US3168834A

US3168834A - Motion converting mechanism

Info

Publication number: US3168834A
Application number: US220238A
Authority: US
Inventors: Charles B Smithson
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-08-29
Filing date: 1962-08-29
Publication date: 1965-02-09
Anticipated expiration: 1982-02-09

Description

Feb. 9, 1965 c. a. SMITHSON 3,168,834

MOTION CONVERTING MECHANISM 5 Sheets-Sheet 1 Filed Aug. 29, 1962 INVENTOR.

B C/zazksBSWow 4 (W/g Feb. 9, 1965 c. B. SMITHSON 3,168,834

MOTION CONVERTING MECHANISM Filed Aug. 29, 1962 5 Sheets-Sheet 2 INVENTOR. C/zarlesflSmzfiwom I I 3 I I a United States Patent 3,168,834 MOTION CONVERTING MEiIHANISM Charles B. Smithson, 33 Country Club Place, Eloomington, Ill. Filed Aug. 29, 1952, Ser. No. 220,238 20 Claims. (Cl. 74-23) This invention relates to improvements in power driven devices generally and more particularly to an improved power driven tool or hand implement such as a toothbrush. More specifically, the invention relates to a novel and improved motion converting means for use in a power driven device.

Various mechanisms have been suggested for power driven toothbrushes whereby the rotary motion of a motor shaft is converted to some type of reciprocating, oscillatory, or orbital motion at the brush or working end of the device. However, the devices heretofore known have had certain disadvantages which have restricted their commercial development and exploitation. For example, the previously known devices have been limited in power output or have been excessive in size in many instances. Furthermore, the motion converting or translating mechanism of such devices has usually been limited with respect to the type of output motion which can be obtained. In addition, in many instances it has been necessary to mount the motor with its drive shaft extending transversely of the longitudinal axis of the casing in order to obtain a desired type of motion at the working end of the device.

The present invention is designed to overcome the foregoing disadvantages ;by means of a novel and improved motion converting or translating mechanism.

Accordingly, a primary object of the invention is to provide a novel and improved motionconverting mechanism for a power driven device, particularly a hand tool or implement.

Another object of the invention is to provide a novel and improved motion converting mechanism for a power driven device which is capable of providing a variety of desired motions at the working end of the device.

A further object of the invention is to provide an improved power driven device having a novel and improved motion converting mechanism characterized by a powerful but compact structure such that the mechanism is particularly useful in a power driven hand tool or implement.

An additional object of the invention is to provide a novel and improved motor driven device wherein the motor is mounted with its drive shaft extending longitudinally of the device and a motion translating mechanism is provided which is capable of converting rotary motion of the drive shaft to a predetermined type of straight line, oscillatory, or orbital motion, or combinations thereof, at the working end of the tool.

Other objects and advantages of the invention will become apparent from the subsequent detailed description taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a reduced scale side elevational view of a power driven toothbrush constituting one specific embodiment of the invention;

FIG. 2 is an enlarged vertical sectional view at the forward end portion of the tooth brush illustrated in FIG. 1;

FIG. 3 is a transverse sectional View taken along the line 3-3 of FIG. 2;

FIG. 4 is a plan view of the interior of the toothbrush with the upper half of the casing removed and. the gear mechanism revolved 90 from the FIG. 2position;

FIG. 5 is a transverse sectional view taken along the line 5-5 of FIG. 4;

FIG. 6 is a schematic view illustrating the different positions of the mechanism shown inFIGS. 2 and 5;

FIG. 7 is a vertical sectional view similar to FIG. 2 but showing a modified form of the invention;

FIG. 8 is a plan view of the interior of the structure shown in FIG. 7 with the upper half of the casing removed and the gear mechanism revolved from the FIG. 7 position;

FIG. 9 is a vertical sectional view similar to FIGS. 2 and 7 but showing another embodiment of the invention;

FIG. 10 is a transverse sectional view taken along the line Iii- 11i) of FIG. 9 with the gearmechanism revolved 90 from the FIG. 9 position;

FIG. 11 is a transverse sectional view taken along the line 11-11 of FIG. 9;

FIG. 12 is a vertical sectional view similar to FIGS. 2 7 and 9 but showing still another embodiment of the invention;

FIG. 13 is a transverse sectional view taken along the line 13-13 of FIG. 12 with the gear mechanism revolved 90 from the FIG. 12position;

FIG. '14 is a vertical sectional view similar to FIGS. 2, 7, 9, and 12 but showing still another embodiment of the invention; FIG. 15 is a transverse sectional view taken along the line Iii-d5 of FIG. 14 with the gear mechanism revolved 90 from the FIG. 14 position;

FIG. 16 is a horizontal sectional view taken along the line 16-1( of FIG. 14 but with the mechanism in a different position;

FIG. 17 is a transverse sectional view taken along the line 17-JL7 of FIG. 14; and

FIG. 18 is a fragmentary vertical sectional view taken substantially along the line 18-18 of FIG. 16.

In FIGS. 1-6, one specific embodiment of the invention is illustrated comprising, in this instance, a power driven toothbrush. Although, for the sake of convenience, the

invention is hereinafter described in connection with a toothbrush, it is to be understood that the principles of the invention, including the novel motion converting mechanism, may also :be used for other typesof power driven devices, particularly tools and implements such as a saw, file, polisher, sander, etc.

As seen in FIG. 1, the toothbrush comprises an elongated housing or casing 2-0 of suitable plastic or other nonconductive material, the casing having detachable upper and

lower halves

21 and 22, respectively, which are held together by screws 25. An electric power cord 23 extends from a reducedportion 24 at the rear end of the casing 29, and a detachable toothbrush 26 having a shank portion 27 and a brush portion 28 is mounted at the forward or nose end of the casing 20. A hand switch 2? projects from one side of the casing 20 for starting and stopping the drive of the toothbrush. Instead of electric power from the cord 23, it will be understood that the casing 21) could be provided with a self-contained power supply such as a battery or the like.

Referring to FIGS. 2-5, an elongated cylindrical motor 31 is mounted within the casing 20' with its drive shaft 32 (FIG. 2) extending longitudinally or axially of the casing 20. The rotary motion of the motor drive shaft 32 is converted to a predetermined desired type of motion at the brush 28 by means of a motion converting or translating mechanism indicated generally at 33 and comprising the principal novel feature of the present invention. 36 are driven in opposite directions by means of a pinion 37 mounted on the motor shaft 32. The

gears

34 and 36 are provided with

hub portions

38 and 39, respectively, which are journaled in a pair of upper and

lower brackets

41 and 42, respectively. The

brackets

41 and 42 are rigidly secured to the motor 31 and extendforwardly therefrom in transversely spaced relation, as best seen in FIG. 2. The

brackets

41 and 42 are provided A pair of spaced coaxial bevel gears 34 and v.3 with beveler openings 43 and 44, respectively, with a plurality of

radial ball bearings

46 and 47 being disposed in the respective openings for journaling the

hub portions

38 and 39 of the gears and retaining the latter in driving relation :with the pinion 37.

The power take-off from the gears 34- and 36 i provided by means of a resilient yoke 48 of spring metal or the like having a pair of upper and

lower arms

49 and 51, respectively, which are interconnected by a laterally enlarged central bight portion 52:. The outer axial ends of the

gear hubs

38 and 39 are provided with restricted sockets 53 and 54, respectively, and the outermost end portions of the

yoke arms

49 and 51 are provided with restricted

apertures

56 and 57, respectively, to accommodate a pair of balls 58 and- 59 therebetween. As best seen in FIG. 2, the sockets 53 and 54 are disposed to one side of or in eccentric relation to the axis.

of rotation of the

ring gears

34 and 36. The spring pressure exerted by the resilient yoke 48 holds the

balls

53 and 59 in driving relation between the

gear hubs

38, 39 and the corresponding

yoke arms

49, 51. rality of ball bearing elements 61 are in rolling engagement between the opposed inner faces of the gears .34 and 36 for receiving the axial thrust of the gears.

As hereinatfer described in more detail, the rotary motion of the pinion 37 on the motor drive shaft is converted by the motion converting means 33 to a combined reciprocating and rocking movement of the yoke 43. This combined motion of the yoke 4-8 is transmitted to an outer socket member 62 having a cylindrical side wall 63, an inner axial end wall 64 abutting the yoke center portion *52, and an outwardly extending flange 66 at the open end of the socket. In this embodiment, a loose swivel connection is provided between the yoke center portion 5.2 and the socket end wall 64 by means of a shoulder screw 67 extending through an enlarged unthreaded opening 68 in the end wall 64 and engaged in a threaded opening 69 in the yoke portion 52. As will be evident from FIG. 2, the aligned openings 6-8 and 69 are off-center or eccentric with respect to the center line of the motor shaft 32 and the yoke '48. For a purpose to be described hereinafter, the socket end wall 64 and the yoke portion 52 are also provided with an enlarged unthreaded opening 71 and a smaller threaded opening 72,

respectively, which are coaxial with the drive shaft 32 and thecenter line of the yoke 48.

The outer socket member 62 has a shiftable fulcrum arrangement so as to permit both straight line reciprocating movement of the socket 62 and also side-to-side pivotal movement; Thus, the 'forward or nose end of the casing 20 has' an enlarged end opening 73 through which the outer socket 62 extends with an annular clearance space 74 (FIG. 3) therebetween. The cylindrical wall 63 of the outer socket 62 is provided with a pair of opposed axially extending grooves 76, and acooperating pair of grooves 77 are provided in the housing opening 73. A pair of rollable ball elements 78 are interposed between the two sets of grooves. Accordingly, the outer socket member 62 which is connected to the yoke 48 can move back and forth in-a longitudinal direction and at the same time the socket 62 can pivot from side to side about the balls 78 as a movable fulcrum within the confines of the annular clearance 74.

For detachably receiving the shank 27 of the toothbrush 26, an inner cylindrical socket member '81 of plastic or the like is detachably secured within the outer socket member 62 by means of a bayonet slot construction 82 having an; interlocking relation with the inwardly depressed portions of the outer socket wall 63 which define the grooves 76. A flexible seal or boot 83 of rubber or other suitable material encloses the forward or nose end oi the casing 2tl and issecured to the latter by means of an annular hangefor head portion 84 which is seated snugly in a circumferential groove 86 encircling the nose end of the casing. The opposite end of the seal 83 is A plu- Y clamped between the fiange 66 of the outer socket 62 and a flange 87 on the inner socket member 8 1 by means of a hat washer 88 and a resilient spring wave washer 89. The spring action of the resilient washer 89 also serves to retain the inner socket member 81 in engaged relation within the outer socket member 62 While at the same time permitting the two socket members to be disconnected by pressing the socket member '81 axially inwardly and rotating the same to disengage the bayonet slot connection 32. Upon withdrawal of the inner socket member 81, the shoulder screw 67 becomes accessible for the purpose hereinafter described. The inner socket member 81 is provided with a square opening 91 for receiving the correspondingly shaped shank 27 of the toothbrush 26, the shank 27 being releasably retained in the socket member 61 by means of a plurality of depressible detents 92 on the shank 27 which are engageable with cooperating recesses 93 at the inner walls of the socket member 81.

To understand the motion of the yoke 48 of the motion converting mechanism 33, it is helpful to consider an imaginary filament or line stretched between the centers of the powertake-

oifball elements

58 and 59. As the

gears

34 and 36 rotate inopposite directions, the power take-off balls 58 and 591are driven in opposite circular paths so that the imaginary line undergoes a compound movement including a back-and-forth reciprocating motion longitudinally of thecasing 20 and also an oscillating or rocking movement transversely of the casing 20 about the axial center line of the motor shaft 32 as a pivot center. However, regardless of the longitudinal displacement of the imaginary line or its transverse inclination, the imaginary line is always perpendicular to the axial center line through the motor shaft 32. g

In FIG. 2, the power take-

off balls

58 and 59 are shown in their extreme forward position wherein the power take-off balls are disposed vertically one above the other so that the yoke 48 is displaced forwardiy the maximum distance of its stroke. This condition of the power take-oil is illustrated schematically in FIG. 6 by the position A of the imaginary line, extending between the power take-off balls. As the

gears

34 and 36 rotate from the FIG. 2 position to the position shown in FIGS. 4 and 5, the imaginary line between the power take-

off balls

58 and 59 is retracted rearwardly in the casing onehalf of its maximum displacement distance and at the same time the imaginary line is inclined in a transverse plane to the position indicated at B in the schematic view of FIG. 6. As the

gears

34 and 36 rotate-another 90, the

balls

58 and 59 and the imaginary line therebetween again assume a vertical position but are now disposed at their extreme rearwardmost position, as indicated schematically at C in FIG. 6. Continued rotation of the

gears

34 and 36 through another to complete a single revolution will cause the imaginary line between the

balls

58 and 59 to pass through an oppositely inclined ends thereof will trace an ellipse whose major axis has the same dimension as the diameter of'the circles traced by the ends of the line and whose minor axis depends on the distance of the point in question from the axial center" line of the motor shaft. Consequently, when'the yoke v4-8 of the motion converting mechanism 33 has a loosepivotal connection with the socket member62 by means, of

the shoulder screw'67 andthe aligned oil-center holes 68 and 69, as shown in FIG. 2, it will beunderstood thatthe motion of the yoke 48- is being transmitted to the socket member 62 at an ellipse-generating point between the center and the upper end extremity of the imaginary line between the

power takeoff balls

58 and 59.

As seen schematically in FIG. 6, the solid line position of the connecting shoulder screw 67 is substantially midway between the center of the imaginary line and the upper extremity defined by the power take-01f ball 58. Thus, the power take-01f point 67 from the yoke 48 generates an ellipse, as illustrated at the bottom of FIG. 6, whose major axis is the same as the distance between the lines A and C and Whose minor axis is the same as the maximum displacement distance of the take-off point 67 in the oppositely inclined positions of the lines B and D. Because of the loose pivotal connection between the yoke 48 and the socket member 62 and because the socket member 62 is restrained from rotating about its central longitudinal axis by reason of the coaction between the fulcrum balls 78 and their

grooves

76 and 77, the elliptical motion generated at the inner end of the socket 62 is substantially reproduced at the brush 28. However, the dimensions of the minor axis of the ellipse will be altered depending upon the relative distances between the shifteble fulcrum and the opposite ends of the moving mechanism comprising the socket wall 64 and the brush 28. By properly proportioning these distances, it is possible to obtain at the brush a motion that is substantially elliptical or substantially circular, either of which paths may be described generically as orbital or as having both longitudinal and lateral components.

Referring to FIGS. 1 and 2, substantially circular motion of the brush 28 or other tool will result if the ratio ezE is the same as the ratio f:F, where e is the distance from the axial center line of the motor shaft 32 to the center of the shoulder screw 67, E is the distance from the same center line to the center of the eccentric power take-

01f ball

58 or 59, f is the distance from the axis of rotation of the

gears

34 and 36 to the movable fulcrum point 78, and F is the distance from the tool point or brush 28 to the same movable fulcrum 78'. If the ratios e:E and fzF are differenna substantially elliptical or non circular orbital motion will be obtained.

It will also be understood that if the shoulder screw 67 is installed through the aligned

openings

71 and 72 which are on the center line of the motor shaft 32, the lateral component of movement of the yoke 48 is completely canceled out and the brush 2.8 undergoes straight line reciprocating movement longitudinally of the casing 20. This condition is also shown schematically in FIG. 6 at the dotted line position of the screw 67 from which it will be seen that the maximum reciprocating distance comprises the distance between the lines A and C, but in a transverse plane the movement of the imaginary line be tween positions B and D causes no lateral displacement of the power take-off point 67. Thus, by locating the shoulder screw 67 in the desired set of holes and by properly proportioning the lengths of the pivot arms extending in opposite directions from the shiftable fulcrum 78, it is possible to obtain in a single tool either straight line reciprocating movement or any desired type of orbital movement, including circular and elliptical paths.

Because of the square configuration of the socket opening 91 and the corresponding configuration of the tool brush shank27, it is possible by properly orienting the brush handle in the socket to take advantage of orbital motion of the brush in several different ways without changing the position of the casing 2t). This characteristic may have particular importance in the case of certain types of tools or implements other than a toothbrush. For example, with the device in the position shown in FIG. 1, the orbital motion at the brush 28 can be used for full or continuous contact polishing, sanding, or cleaning of a top surface or the like. By reversing the position of the brush member 180 so that the brush portion or other tool point extends upwardly instead of downwardly, the same type of continuous or full con- 6 tact may be obtained for working on the underside of a surface or the like. In the case of a different type of tool or implement, such as a saw blade or file, the square shank of the tool can be oriented in the inner socket 81 so that the orbital motion is imparted to the tool point in a vertical plane instead of in a horizontal plane as in FIG. 1. Thus, the tool point will have a rolling or stroking motion relative to the work which would provide for automatic cleaning on the return stroke in the case of a saw blade or file.

It will also be evident that with the motion converting mechanism 33, still other modifications may be realized to obtain additional types of output motions. For example in FIG. 2 the outer socket 62 may be rotatably supported in the casing opening 73 by suitable annular bearing means and may also be rigidly connected to the yoke portion 52 with the longitudinal axis of the socket in coaxial relation with the motor shaft 32. With this modification, it will readily be understood that the socket member 62 will undergo straight back and forth reciprocating movement combined with oscillating rotary movement about its longitudinal axis. This motion is particularly useful for chip clearance and removal in a drilltype boring tool.

The use of a pair of

opposed gears

34 and 36 in the manner described has special advantage in the case of relatively small hand tools or implements because of the compactness of the design which at the same time permits the motor 31 to be mounted in longitudinal relation in the casing 20. Inasmuch as only one-half the total power output is being taken from each gear, the gears can be made substantially smaller than would otherwise be the case thereby realizing a compact construction with out sacrificing power output.

FIGS. 7 and 8 illustrate a modification of the motion converting mechanism 33 heretofore described. Those portions of the structure which are essentially the same as in FIGS. 1 to 5 are. identified by the same reference numerals in FIGS. 7 and 8. In this modification the upper gear 34 of the first embodiment has been eliminated and in place thereof a bracket 96 has beensubstituted, the bracket having a horizontal portion 97 extending rigidly from the end of the motor 31 and being pro vided at its underside with a suitable raceway for the thrust ball elements 61. The spring yoke member in this instance is designated generally at 93 and has a lower arm 99 and a central portion 161 which are essentially the same as the arm 51 and the portion 52 in the first described embodiment. The lower arm 99 has a restricted opening 102 for receiving the power take-off ball 59 in the manner previously described. The central portion 101 of the yoke 98 has the same connection with the outer socket member 62 which need not be described in further detail.

At the upper end of the yoke 98 a horizontal arm portron 103 is disposed adjacent the bracket portion 97 and is integrally connected to the central yoke section 101 by means of an inverted U-shaped connecting portion 104. The bracket portion 97 and the opposedyoke arm 163 are provided with confronting

grooves

106 and 167, respectively, and a ball bearing element 103 is disposed therebetween. The groove 1061's arranged parallel to the axial center eccentric power take-off ball 59 undergoes circular movement during rotation of the ring gear 36, the ball bearing element 168 supports the yoke arm 103 for back-andforth reciprocating movement while at the same time accommodating transverse rocking or swivel movement of the yoke arm 193 about the ball element 108 Thus, with the use of only a single gear 36 driven by the pinion 37, the same selective straight line or orbital movement may be obtained from the motion converting mechanism. However, in this case the shoulder screw openings 68 and 69 are aligned axially with the center line of the path of line of the motor shaft 32 so that as the areassa reciprocating movement of the ball 1118 and with the shoulder screw 67 in these openings the socket 62 undergoes straight reciprocating movement. When the

openings

71 and 72 are utilized, orbital motion is obtained.

F168. 9 to 11 illustrate another embodiment of the invention utilizing a diiierent socket fulcrum arrangement and a'dififerent power take-oil means from the rotating gear. The casing comprises two

sections

111 and 112 housing a motor 113 which drives a pinion gear 114. A pair of bevel gears 115 and 117 of plastic or the like have

integral hub portions

118 and 119, respectively, which are journaled in

tubular bosses

121 and 122, respectively, projecting from the wall of the casing. The

gears

116 and 117 are driven in opposite directions by the pinion 114.

A pair of

metal swivel balls

123 and 124 are rotatably mounted in corresponding sockets in the

gears

116 and 117 in eccentric relation with respect to the axis of rotation of the gears and projecting slightly from the opposed faces of the gears. The balls may be molded in place during fabrication of the plastic gears and thereafter may be broken free of the plastic material. The sockets are then suitably lubricated to permit free swivel movement of the balls. The

halls

123 and 124 are interconnected by means of a shaft segment or pin 126 which performs the essential function of the

yoke

48 or 98 in the previously described embodiments of the invention. The opposite ends of the pin 126 are slidable in suitable bores in the

balls

123 and 124 to accommodate rotation of the gears. An intermediate swivel ball element 127' is axially bored and is slidably andadjustably mounted on the pin 126 intermediate the

end ball elements

123 and 124. The swivel ball element 127 is also rotatably retained in swivel relation in a complementary socket portion formed at the inner end extension 128 of a plastic socket member 129 having a square or non-circular external cross-section. The socket member 129 is also provided with an inner opening 131 of square cross-section for detachably receiving the toothbrush shank 27 or other tool in the same manner as heretofore described. The outermost end of the socket member 129 has a circumferentially grooved flange portion 132 for receiving the beaded end 133 of a flexible rubber seal 134. The opposite end 136 of the seal 134 is retained in a groove 137 at the end of the casing. Asbefore, the function of the seal 134 is to enclose an enlarged opening 135 at the forward end of the casing and through which the socket member 129 extends.

In this instance, the fulcrum for the socket member 129 comprises a square tubular section 138 having the square socket member 129 slidably disposed therein but restrained against rotation about its longitudinal axis. The fulcrum member 138 has oppositely extending integral shaft extensions or pin portions'139 and 141 which are rotatably journaled in and axially shit-table in a pair of tubular bearing bosses 1 12 and 143, respectively, extending inwardly from the casing. A coil spring 14-4 is interposed between one side of the fulcrum member 138 and the casing section 111 for urging the fulcrum member 138 toward the opposite casing section 112. An adjusting screw 146 is threaded into the tubular bearing boss 143 and has an enlarged head portion 147 disposed at the exterior of the casing for manipulating the same. The inner end of the screw 146 abuts the pivot pin 141 of the fulcrum member 138. By reason of the slid-able relationship between the swivel ball 127 and the shaft segment i 126, it will be seen that the position of the swivel ball element 127 relative to the

rotating ball elements

123 and 124 can readily be adjusted by means of the screw 146 which regulates the transverse position of the vfulcrum member 138.

By adjustment of the position of the swivel ball element 127, it will be understood that the power take-off point for the socket member 129 is correspondingly adjusted

halves

151 and 152 which contain a motor 153having a plane therethrough.

thereby determining the straight line or orbital character of the path of movement transmitted to the brush or other tool. axial center line of the motor shaft, the socket member 129 will undergo a simple back-anddorth straight line reciprocating movement. However, when the swivel ball element 127 is located in a position intermediate the motor shafit center line and one of the

balls

123 or 124,

an orbital movement is transmitted to the brush which may be either circular or elliptical dependent upon the proportioning factors heretofore discussed. It will also be understood that if the ball 127 is located between the center line of the motor shaft and the ball element 123, the path of orbital movement will be in one direction, whereas if the ball element 127 is located between the motor shaft center line and the opposite swivel ball element 124, the path of orbital movement will be in the opposite direction. Thus, the invention provides a very simple and convenient method of reversing the direction of orbital movement of the tool point without the necessity tor a reversible motor. 7.

In the position of the motion converting mechanism shown in FIG. 9, the eccentrically located

swivel ball elements

123 and 124 are disposed one above the other in a vertical line and are located at the point of maximum forward displacement. It will be understood that when the

gears

116 and 117 have rotated 180 from the FIG. 9 position, the

balls

123 and 124 will again be disposed one above the other in vertical relation but at the point of maximum rearward displacement. Consequently, a back- .and-forth reciprocating movement is imparted to the socket member 129 longitudinally of the casing. At the same time, as the

gears

116 and 117 rotate and 270 from the FIG. 9 position, the

ball elements

122 and 123 are disposed at opposite sides of'the gear axis (FIG. 10) to impart a lateral component of movement in a plane transversely of the casing.

A further variation in this type of motion at the brush or tool point may be obtained by locating the swivel balls posed adjacent opposite sides of .the casing in a transverse seen that the center point of the pin 126 undergoes lateral back-and-ttonth movement in a straight line transversely of the casing, and if the swivel ball 127 is located at the center point of the pin 126, a similar lateral backand-forth swinging movement will be imparted to the brush or tool point. Actually, because of the pivoted fulcrum 138 the brush or tool point will have a slight arcuate path from side to side but the curvature is so minute that to the eye it will appear as a straight line. Thus, by varying the eccentric locations of the swivel balls 12?: and 124 relative to the gears and to each other and by varying the location of the intermediate swivel ball 127 relative to the end balls 123 and 124-, a wide variety of compound motions may be obtained at the brush or tool point.

FIGS. 12 and 13 illustrate a modification of the. arrangement shown in FIGS. 9-11 whereby oscillatory movement of the .tool socket and tool or brush about its center line is obtained. The casing has upper and lower pinion 154 on its shaft. A pair of

plastic bevel gears

156 and 157 are journaled in

tubular bosses

158 and 159 extending from the casing wall and are driven in opposite directions by the pinion 154 in the same manner as in the previous embodiment of FIGS. 9 to 11. Power takeoff from the

gears

156 and 157 is again accomplished by means of a pair of

swivel balls

161 and 162 retained in swivel relation in corresponding socket portions in the

gears

156 and 157 and interconnected by a shaft segment When the swivel ball element 127 is located on the With this relationship, it will'be 9 opening 166 therethrough for slidably receiving an elongated rearward extension 167 of a plastic socket member 168.

The socket member 168 is cylindrical but has a rectangular opening 169 for detachably receiving the shank of a brush or other tool member in the manner previously described. The forward end of the casing has a reduced diameter nose portion 171 with an opening 172 through which the socket 168 extends. A cup-shaped flexible rubber seal 173 has a flanged end 174 retained in a circumferential groove 176 around the outside of the nose POD" tion 171, and the outer end of the seal 173 comprises an apertured wall or annular lip portion 177 in resilient engagement with an annular flange 173 extending integrally and outwardly from the socket member 168. The socket member 168 and the opening 172 are provided with opposed

circumferential grooves

179 and 181, respectively, with a plurality of ball bearing elements 182 disposed therebetween for rotatably supporting the socket member.

The motion imparted to the shaft segment 163 by means of the oppositely

rotating gears

156 and 157 is the same as in the embodiment of FIGS. 9-11. However, in this instance, the socket member 168 is restrained against longitudinal or axial movement by the ball elements 182 but is free to rotate about its central longitudinal axis. Consequently, the socket extension 167 remains in fixed position longitudinally of the casing but the enlarged section 164 of the shaft segment slides back and forth between the full line and dotted line positions shown in FiG. 12 as the

gears

156 and 157 rotate. During rotation of the gears, the shaft segment 163 also rocks from side to side transversely of the casing between the full line and dotted line inclined positions shown in FIG. 13, and the keyed relationship between the shaft segment portion 164 and the socket extension 167 causes the socket 168 to oscillate back and forth about its longitudinal axis through an arc of about 60. Accordingly, the tooth brush or other tool point undergoes the same rotary or oscillating movement.

A combination of the above-described oscillatory motion and straight axial reciprocation can also be obtained with the structure of FIGS. 12-13 by changing the support for socket 168 to permit both types of motion and at the same time rigidly connecting the socket extension 167 and the segment 163 at the center point of the latter.

FIGS. 14-18 illustrate a further modification of the embodiment of FIGS. 9-11 wherein the shiftable fulcrum for the socket is disposed rearwardly of the gear axis and the connecting shaft segment rather than forwardly thereof. The casing has upper and

lower halves

136 and 187 with a motor 188 contained therein, a pinion 189 mounted on the motor shaft, and a pair of plastic gears 191 and 192 journaled in tubular bosses extending from the easing walls and driven in opposite directions by the pinion 189. The power take-off swivel ball elements are designated at 193 and 194 and are interconnected by a shaft segment 196 in the same manner as previously described.

An intermediate swivel ball element 197 is provided on the shaft segment 196 and is retained in swivel relation in an elongated extension 193 projecting rearwardly from a socket member 199 of rectangular external shape. The socket extension 198 is fork shaped, as best seen in FIG. 16, and has a pair of laterally spaced arms 291 projecting rearwardly beyond the axis of the ring gears 191 and 192. Each arm 261 extends between a pair of upper and

lower shoulders

202 and 203, respectively, provided in the easing. The arms 201 are slotted, as at 264, and the shoulders 2G2 and 203 are provided with corresponding grooves 206 with a pair of ball elements 207 disposed between each groove 206 and the confronting side of the slot 204. Thus, a pair of movable fulcrums are provided rearwardly of the power take-off connection which accommodate both back-and-forth reciprocating movement 1d and side-to-side pivotal movement of the forked socket extension 198.

The nose end of the casing has a rectangular end opening 208 with outwardly tapering side wall portions 209 (FIG. 16) to accommodate side-to-side swinging move ment of the socket member 199. Bearing support for the socket member 199 is provided by means of a pair of ball elements 211 seated in a pair of shallow circular recesses or sockets 212 and rollably engaging the flat upper and lower surfaces of the socket member 199. The circular recesses 212 are of relatively large diameter compared to the diameter of the balls 211 so as to accommodate combined back-and-forth reciprocating and side-toside pivotal movement of the socket member 199.

As before, the socket member 199 has a square central opening 213 for detachably receiving the shank of a tooth brush or other tool member. Likewise, the forward end of the socket member 199 has a grooved construction similar to that shown in FIG. 9 and is provided with a flexible rubber seal 214 extending between the grooved end of the socket member and a similar groove in the nose of the casing.

As will be recognized, the location of the swivel ball element 197 along the shaft segment 1% is fixed in this instance so that the mechanism cannot be adjusted to provide either straight line or orbital movement, as may be desired. In the arrangement shown in FIGS. 14-18, the ball element 197 is located between the center line of the motor drive shaft and the lower swivel ball 194 so as to transmit an orbital motion to the socket member 199 in one direction. If the swivel ball 197 is located between the motor shaft center line and the upper swivel ball 193, and orbital path in the opposite direction is provided.

Although the invention has been described with particular reference to certain specific structural embodiments thereof, it shouldbe understood that various alternatives and equivalent structures may be resorted to Without departing from the scope of the invention as defined in the appended claims.

I claim;

1, Motion converting means for use in a power driven tool or the like comprising, in combination, a rotatably driven gear element, a power take-01f member having spaced end portions, means providing a swivel driving connection between one of said end portions and said gear element in eccentric relation to the axis of rotation of said gear element, means axially spaced from said gear element providing a swivel support for the other of said end portions, means mounting said swivel support for movement of said other end portion relative to said axis during rotation of said gear element, and movably supported means connected to said power take-01f member at an intermediate portion thereof between said end portions for receiving and transmitting the resultant motion of said powertake-olf member.

2. In a power driven device, the combination of an elongated housing, a motor in said housing having a drive shaft extending longitudinally of said housing, a drive gear element mounted on said shaft, a socket member movably supported at one end of said housing for mounting a tool or the like, and motion converting means interconnecting said drive gear element and said socket member, said motion converting means comprising a driven gear element meshed with said drive gear element and mounted for rotation in said housing on an axis extending transversely of said drive shaft, a power take-off member having spaced end portions, means providing a swivel driving connection between one of said end portions and said driven gear element in eccentric relation to said axis, means axially spaced from said driven gear element providing a swivel support for the other of said end portions, means mounting said swivel support for movement of said other end portion relative to said axis during rotation of said driven gear element, and means connecting said socket member to said power take-01f member at an intermediate portion thereof between said end portions.

3. In a power driven device, the combination of a motor driven shaft, a pinion on said shaft, a gear element mounted for rotation on an axis transverse to said shaft and meshed with said pinion, a yoke member having spaced arm portions and a central portion between said arm portions, means providing a swivel driving connection between one of said arm portions and said gear element in eccentric relation to said axis, means axially spaced from said gear element providing a movable swivel support for the other of said arm portions, and movably supported means connected to said central portion of said yoke member for receiving and transmitting the resultant motion of said yoke member.

4. In a power driven device, the combination of a motor driven shaft, a pair of spaced coaxial gear elements mounted for rotation on an axis transverse to said shaft, means driven by said shaft for rotating said gear elements in opposite directions, a power take-off member having spaced end portions, means providing a swivel driving connection between each of said end portions and one of said gear elements in eccentric relation to said axis, and movably supported means connected to said power take-off member at an intermediate portion thereof between said end portions for receiving and transmitting the resultant motion of said power take-off member.

5. In a power driven device including an elongated housing and a motor mounted in the housing with its shaft extending longitudinally of the housing, the combination of a pair of spaced coaxial gear elements mounted for rotation on an axis transverse to said shaft, a pinion on said shaft meshed with said gear elementsfor rotating the latter in opposite directions, a yoke member having resilient spaced arm portions disposed adjacent said gear elements and a central portion between said arm portions, means comprising a pair of ball elements in swivel engagement with said arm portions and the respective gear elements in eccentric relation to said axis for providing a driving connection between said gear elements and said yoke member, a socket member extending longitudinally of said housing and movably supported therein for mounting a tool or the like, and means connecting said socket memher to said central portion of said yoke member.

6. The structure of claim 5 further characterized in that said socket member and said casing are provided with longitudinally shiftable fulcrum means for said socket member and'means for restraining said socket member against rotation about its axis, and said socket member has an axial end wall pivotally connected to said central portion of said yokemember whereby to accommodate rocking of said yoke member relative to said socket member. I

7. The structure of claim 6 further characterized in that said end wall portion of said socket member and said central portion of said yoke member are provided with one pair of aligned apertures disposed on the axis of said shaftand atleast one other pair of aligned apertures offset from the axis of said shaft, and detachable pivot connecting means is provided for selective engagement in either pair of apertures whereby to provide either straight line reciprocating or orbital movement of said socket member.

8. In a power driven device including an elongated housing and a motor mounted in the housing with its shaft extending longitudinally of the housing, the combination of a gear element mounted for rotation on an axis transverse to said shaft, a pinion on said shaft meshed with said gear element for rotating the latter, a rigid support spaced axially from said gear element, a yoke member having resilient spaced arm portions disposed adjacent said gear element and said support, respectively, and a central portion between said arm portions, means comprising a first ball element in swivel engagement between one of said arm portions and said gear element in eccentric relation to said axis for providing a driving connection therebetween, means comprising confronting guide portions on said support and. on the other of said arm portions and a second ball element received therebetween for providing a movable swivel support for said other arm portion, said guide portions being disposed so as to restrict movement of said second ball element in a straight path parallel to the axis of said shaft, a socket member extending longitudinally of said housing andmovably supported therein for mounting a tool or the like, and means connecting said socket member to said central portion of said yoke member.

9. The structure of claim 8 further characterized in that said socket member and said casing are provided with longitudinally shiftable fulcrum means for said socket member and means for restraining said socket member against rotation about its axis, and said socket member.

has an axial end wall pivotally connected to said central portion of said yoke member whereby to accommodate rocking of said yoke member relative to said socket member.

10. The structure of claim 9 further characterized in that said end wall portion of said socket member and said central. portion of said yoke member are provided with one pair of aligned apertures disposed in axial alignment with said=path and at least one other pair of aligned apertures offset from said path, and detachable pivot connecting means is provided for selective engagement in either pair of apertures whereby to provide either straight line reciprocating or orbital movement of said socket member.

11. In a power driven device the combination of a motor driven shaft, a pinion on said shaft, a pair of spaced coaxial gear elements mounted for rotation on an axis transverse to said shaft and meshed with said pinion for rotating said gear elements in opposite directions, swivel means carried at the opposed faces of said gear elements in eccentric relation to said axis, an elongated connecting member extending between said gear elements with the opposite ends of said connecting member movably engaging said swivel means, and movably supported means connected to said connecting member at an intermediate portion of the latter between said ends for receiving and transmitting the resultant motion of said connecting member.

12.. The structure of claim 11 further characterized in that said swivel means comprises a pair of ball elements having a swivel mounting in said gear elements and said connecting member comprises a pin with its opposite ends slidably received in said ball elements.

13. The structure of claim 12 further characterized in that said movably supported means comprises a socket member connected to said pin intermediate the ends of the latter by means slidably adjustable lengthwise of the pin and mounted in swivel relation to said socket member.

14. The structure of claim 12 further characterized in that said pin has an intermediate ball element slidably mounted thereon intermediate said pair of ball elements and said movably supported means comprises a socket member having an extension with said intermediate ball element mounted in swivel relation in said extension.

15. The structure of claim 14 further characterized by the provision of a tubular fulcrum support for slidably, receiving said socket member and restraining the same against rotation about its axis, means pivotally mounting the provision of a pair of pivots extending from opposite sides of said fulcrum support, means supporting said pivots for rotary and axial sliding movement, spring means 13 at one side of said fulcrum support for urging said fulcrum support in one direction, and threaded adjustm nt means at the opposite side of said fulcrum support for regulating the position of said fulcrum support and said socket member.

17. The structure of claim 12 further characterized in that said movably supported means comprises a socket member supported for rotary oscillation about its axis With means providing a non-rotatable but longitudinally slidahle connection between said socket member and an intermediate portion of said pin.

18. The structure of claim 17 further characterized in that said pin has an enlarged intermediate portion With a non-circular aperture and said socket member has an elongated extension of non-circular cross-section slidably disposed through said aperture.

19. The structure of claim 12 further characterized in that said movably supported means comprises a socket member supported for orb a1 movement forwardly of said pin, a rearward extension on said socket member having a swivel connection with an intermediate portion of said pin and a pair of yoke arms projecting rearwardly beyond said pin, and means coacting With said yoke arms and providing a pair of oppositely disposed shiftable fulcrum supports for said yoke arms.

20. The structure of claim 19 further characterized in that said last-named means comprises guide portions confronting said yoke arms and ball means interposed thereoetween.

References Cited in the file of this patent UNITED STATES PATENTS 1,956,281 Granberg Apr. 24, 1934 2,372,731 Nalbach et a1 Apr. 3, 1945 2,648,787 Smithson Aug. 11, 1953 2,657,321 Smithson Oct. 27, 1953

Claims

1. MOTION CONVERTING MEANS FOR USE IN A POWER DRIVEN TOOL OR THE LIKE COMPRISING, IN COMBINATION, A ROTATABLY DRIVEN GEAR ELEMENT, A POWER TAKE-OFF MEMBER HAVING SPACED END PORTIONS, MEANS PROVIDING A SWIVEL DRIVING CONNECTION BETWEEN ONE OF SAID END PORTIONS AND SAID GEAR ELEMENT IN ECCENTRIC RELATION TO THE AXIS OF ROTATION OF SAID GEAR ELEMENT, MEANS AXIALLY SPACED FROM SAID GEAR ELEMENT PROVIDING A SWIVEL SUPPORT FOR THE OTHER OF SAID END PORTIONS, MEANS MOUNTING SAID SWIVEL SUPPORT FOR MOVEMENT OF SAID OTHER END PORTION RELATIVE TO SAID AXIS DURING ROTATION OF SAID GEAR ELEMENT, AND MOVABLY SUPPORTED MEANS CONNECTED TO SAID POWER TAKE-OFF MEMBER AT AN INTERMEDIATE PORTION THEREOF BETWEEN SAID END PORTIONS FOR RECEIVING AND TRANSMITTING THE RESULTANT MOTION OF SAID POWER TAKE-OFF MEMBER.