US2711110A - Power driven open-end ratcheting wrench - Google Patents

Description

June 21, 1955 A, J, BRAME 2,711,110

POWER DRIVEN OPEN-.END RATCHETING WRENCH Filed oct. 8, 1952 2 sneek-sheet 1 ATTORNEYS June 2l, 1955 A, Jl BRAME v 2,711,110

POWER DRIVEN OPEN-END RATCHETI'NG WRENCH Filed oct. s, 1952 K 2 sheets-sheet 2` l 25 FIG. 5.r

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IN VENTOR ALLEN J. BRAME MTORNEYS United States Patent 0 POWER DRIVEN OPEN-END RATCHETING WRENCH Allen J. Brame, Los Angeles, Calif., assignor to Tubing Appliance Company, Inc., Los Angeles, Calif., a corporation of California Application October 8, 1952, Serial No. 313,728

17 Claims. (Cl. 8158.1)

This invention relates to improvements in open-end ratcheting wrenches of the general type exemplied in my copending applications Serial No. 261,103 tiled December 1l, 1951 and Serial No. 300,260 filed Julyv22, 1952 and in the patent to Fish No. 2,578,687.

More particularly, the invention relates to improved wrenches of the general type indicated above, the improved wrenches being especially although not exclusively adapted to be power driven.

An object of the invention is to provide improved openend wrenches which embody the structurally advantageous features of the above mentioned type of wrenches together with the functionally advantageous features thereof and which involve improvements in the forms and relative arrangements of their components, which endow the improved wrenches with greaterfruggedness mechanic can rotate nuts on tubing, conduit, cable, shaftl;

ing and the like to which the wrench is applied, with greater facility, ease, and eciency than heretofore attainable, and complete the tightening of a nut or the like much more quickly.

lt is also an object of the invention to provide an irn-` proved power-driven wrench of the character Vindicated above wherein the housing or head is composed of two substantially similar stamped sections or halves, each having registered lateral flanges which form the sidewalls of ,g wrenches.

the housing or head when the sections are assembled, and registered extensions which form the bearing support or enclosure for the actuating shaft bearing when the sections are assembled.

A further object of the invention is the provision of i an improved wrench of the character indicated above wherein flanges are provided on the assembled sections for a hub carrying the work gripping component or wrench socket, one of the flanges being a shear ange and another a guide flange, the hub being formed inopposite sides with arcuate concentric grooves which receive the anges, whereby the hub is positively guided the line 4&4 of Figur 3S 2,711,110 Patented June 21, 1955 head or housing, and `Vthe sectionassembling or fasten'- ing means.

A further object of the invention is' to provide im= proved power-driven open-end ratche'ting wrenches which are driven or operated by axially rotated power driven actuating shafts, journalled in bearing means supported and housed within a portion of housings enclosing the ratchet mechanism and Aconstituting the heads of the wrenches, the actuating shafts being located in a plane substantially parallel-to and located between'the webs of the housing sections and being preferably radial with respect to the geometric center of the head or housing, so that the wrenches have atand low profiles enabling reaching and turning nutsvon pipe or the like through conned spaces not much wider than the thickness f the heads or housings of the wrenches and not much longer than the width of the heads or housings.

Av still further object of the invention involves the pro vision of an improved wrench of the character indicated above in which an axially rotatable actuating shaft care ries an eccentric or rotary cam within the housing or head which is operatively engaged with the ratchet pawl carrier for operating the ratchet pwl carriernr one direction.

Another object of the invention is the provision of improved wrenches of the character indicated Vabove wherein the axially rotatable actuating shaft is positioned radl= ally with respect to the center of curvature of the arcuate path of movement of the ratchet pawl carrier whose arcuate movement produces arcuate movement of a hub on which the work engaging member is mounted.

Still another object of the invention is to provide im`- proved wrenches of the character indicated above wherein the rotary actuating shaft is positioned radially also with respect to the center of curvature of the arcuate path of movements of the ratchet pawl carrier and the hub, and the shaft is positioned substantially in the same' plane as the ratchet, carrier and the hub.

A further object of the invention is to provide improved Wrenches of the character indicated above which can be fabricated and assembled at a cost much less than the wrench of the herein mentioned Fish patent, and which can more than adequately replace present open-end wrenches, and which can, by proper heat treatment of the stamped housing sections `and other components of the wrench, take greater working loads than present A still further object of the invention is to provide a preferably power-driven open-end ratchet wrench of Vthe' general. character indicated above wherein the head or' housing is composed of two superimposed stamped sections, the lower section being hollow and open at its to`p` and containing the hub, tlie hub guiding means, the ratchet mechanism, and the tubular carrier, or enclosure forthe bearing of the actuating shaft and being the load bear'-` ing section, the other or upper head or housing section 53 being in the fonn of a at plate serving as a cover for the open upperV end of the lower section and serving merely as a retainer for certain of the components within the hollow' lower section.`

' Other important objects and advantageous features of,l the invention will be apparent from theffollowing d'escription and the accompanying drawings, whereimfor purposes of illustration only, specific embodiments of the invention are set forth in detail.

In` the drawings:

Figure 1 is a side edge elevation of an embodiment;

Figure 2 is atop plan view thereof;

Figure 3 is a plan view with the upper housing or head section removed;

Figure 4 isa vertical longitudinal section taken on Figure 5 is a transverse vertical section taken on the line 5 5 of Figure 4; e

Figure 6 is a fragmentary transverse vertical Sectio taken on the line 6-6 of Figure 3;

Figure 7 is a fragmentary transverse vertical section taken on the line 7 7 of Figure 3;

l Figure 8 is a fragmentary transverse vertical section taken on the line 8 8 of Figure 3;

dFigure 9 is a top plan view of another embodiment; an

Figure 10 is a vertical longitudinal section taken on the line 10-10 of Figure 9.

Referring in detail to the drawings, wherein like numerals designate like parts throughout the several views, and irst to Figures l to 8, the open end ratcheting wrench therein shown and generally designated A, cornprises a head or housing composed of a pair of superimposed and registered head or housing sections 16 and 17, hereinafter conveniently referred to as the upper and lower head or housing sections, respectively, and as the retaining section and load bearing section, respectively.

The sections 16 and 17 consistof substantially identical stampings of generally oval shape in plan, each involvingV a plain flat web 18 having thereon a lateral peripheral flange 19 extending therearound. The sections are provided in one end, hereinafter conveniently referred to as the forward end, with registering longitudinal slots which together form a mouth 20 which opens into a circular' hub receiving opening 21 which extends through both sections. the flanges 19 abut and, as shown in Figure 1, a linger 22 on the upper section 16 engaging a recess 22 on the lower section 17 facilitates orientation of the-sections in being assembled and keeps the sections from shifting out of registery.

Bolts or rivets 23, 23 are passed through peripheral portions of the section Webs 18, as shown in Figures 2 and 7, for holding the assembled sections together, the heads of the fasteners preferably being located in depressions ordimples 24, 24 in the webs to avoid projection of the heads beyond the outer faces of the webs 18, 18.

The webs of the sections are distorted at points adjacent to their rear ends to provide arcuate clearance chambers 25, 25 which extend longitudinally and centrally of the sections and provide roorn for operation of an eccentric or rotary cam hereinafter described.

Semi-cylindrical extensions 26, 26 arranged longitudinally preferably on the center lines of the sections 16 and 17 project rearwardly from the rear ends of the sections and register to form a cylindrical actuating shaft bearing support or enclosure 27. An assembling ring 28 encircles the extensions 26, 26 and serves to hold the extensions together and in supporting relation to the outer race 29 of an annular actuating shaft bearing 3i) positioned longitudinally in the enclosure 27, preferably in axial alignment with the longitudinal center lines of the sections 16 and 17, and preferably axially aligned with a longitudinal line through the housing or head 15 which is midway between and parallel to the webs 18 of the sections.

As shown in Figure 4, the bearing 30 is preferably a needle-type roller bearing, and is held in place in the enclosure 27 by suitable means, such as the retaining ring 31. An actuating shaft 32 extends axially through the inner race 33 of the bearing 30 and projects into the interior of the housing 15 at the rear end` of the housing.

The outer or rear end of the actuating shaft 32 is adapted to be connected in a suitable manner (not shown) to means for rotating the shaft, preferably a motor or other power take-off (not shown).

The inner or forward end 34 of the actuating shaft 32 which projects into the rear part of the interior of the housing 15 is eccentric with respect tothe axis of the shaft 32. On the eccentric shaft end 34 is ixed the inner race 35 of a rotary carn bearing 36, preferably a needle- In their assembled relation, the free edges of 4 type roller bearing. The outer race of the cam bearing 36 is in the form of a cam ring or face 38. A retaining i ring 39 is seated in a groove 40 in the eccentric shaft end 34 for holding the bearing 36 in place between the ring 39 and an annular thrust shoulder 37 formed on the shaft 32 at the rearward end of the cam bearing 36, as shown in Figures 3 and 4.

A ratchet pawl carrier 41 is positioned within the housing 15 in the space between the rotary eccentric cam tively deep depending right angular flange 43 which is' arcuate in horizontal cross section so as to conformably and slidably bear against the rearward side, constituted by an annular row of ratchet teeth 44, of a substantially v semi-circular rotary hub 45. On its yforward edge the carrier plate 41 has a relatively shallow depending arcuate guide flange 46 which engages downwardly in an arcuate guide groove 47 provided in the hub 45. The top surface 48 of the carrier plate 41 is slidably engaged by the underf surface of the web 18 of the upper housing section 16; as shown in Figure 4, and is thereby held down in place in operative engagement, as above described, with the hub 45. .The carrier plate 41 operates in a plane parallel lto the webs 18 of the housing sections and parallel to the axis of the cam ring 38 and the actuating shaft 32.

Operative connection between the carrier plate 41 and the rotary cam ring 38 is provided by a earn lobe or v follower 50 which is in the form of a nger projecting rearwardly from the rearward edge of the carrier plate" 41 at a slightly obtuse angle to the axis of the. rotary cam. The follower 50 terminates at its free end in' a cam surface or end 51 conformably engaging the periph-l eral surface of the cam ring 38. Expanding compressible helical springs 52, 52 are compressed between lugs 53,. 53 on the sidewall of the housing 15, defined by the section flanges 19 and portions on the upper and lower-V sides of the cam follower 50. The springs 52 are located in the housing 15 at the same side of the cam as the cani follower and serve to yieldably maintain the cam surface 51 in constant engagement with the peripheral' surface of the cam ring 38. The arrangement of the K springs 52, 52 atand in thrust engagement with the carrier plate/41 at opposite sides' of the carrier plate 4i.l

serves to stabilize and case the operation of the carrier plate and to maintain constant the predetermined angle of engagement of the cam follower with the cani.

lt will be obvious from the foregoing that upon rotation of the actuating shaft 32, by suitable means, the eccentric rotation of the cam willproduce reciprocalion of the carrier plate 41 crosswise of the housing aud back and forth along the row of ratchet teeth 44 on the hub 45, and in so doing produce step-by-step rotation annulus 58 which is formed with the aforementioned` ratchet teeth 44. The upper and lower sides ofthe toothed annulus 58 are axially spaced from vthe edges 56 and 57, respectively, of the annulus 55. The upper.

side of the toothed annulus 58 contains the guide groove 47l which vis engaged bythe vshallow'er `ange 460i thecarrier plate 41. The lower side of the toothed annulus 58 is provided with an arcuate load carrying groove 61 registering with and coextensive with the guide groove 47. The load carrying groove 61 engages an arcuate load carrying or shear iiange or rib`62 which is formed on and projects upwardly from the web 18 of the lower housing section 17, as shown in Figure 4. The hub 45 is thereby stabilized in the housing 15 and eased in its rotation relative thereto. In addition, the conf forming and closely .sliding interengagement of the grooves 47 and 61 of the toothed annulus 58, with the flanges 43 and 46 of the ratchet pawl carrier plate 41, and the engagement of the hub and the carrier plate with the webs 18 of the housing sections together elimi nate twisting and shearing strains upon the moving parts and transmit or transfer all shearing' stresses directly and almost exclusively to the housing and to the fasteners 23 securing the housing sections together. Further, and importantly, through the engagement of the load carrying groove 61 and load carrying iiange 62, the lower housing section is made to serve as the load carrying member of the wrench. The load carrying flange 62 is arcuate and extends around the circular opening 21 of the housing 15 in which the hub 45 rotates. The ratchet pawl carrier guide flange 46 is similar to the load carrying fiange 62 and is opposed to the load carrying flange 62 and is engaged in the groove. 47 of the hub 45. Because of this the iianges 46' and 62 actas oppositely directed shear iianges which support the hub in its rotative movements occurring in the. use and operation of the wrench. The forces thus introduced into the wrench are transmitted from the hub 45 to the lower housing section 17 and to the ratchet pawl car` rier 41 when a torsional moment is applied to a nut engaging member, such as the member 67, heldby the hub 45. The moments applied to the pawl` carrier 41 by the pawls 42, 42 are taken out through the flange 46 and groove 47, forming parts of `hub reinforcing means.

The upper housing section 16 carries practically no loads and acts merely as retaining and positioning means for the hub 45 and pawl carrier 41, the only moments applied to the upper housing section -I6 occurring by the action of the pawl carrier 41 as it is moved-first by the cam 36 and then by the springsv 52, S2 in oppo site directions. l

The annulus of the ratchet wheel or hub 45,1ike. the hubs or ratchet wheels of the above mentioned copending applications, is formed with a diametrical slot arranged to be registered with the mouth 20 inthe forward end of the head or housing 15 in an appropriate. rotated position of the hub 45. .The hub 45 has an axial opening or concave surface whereby the hub serves as a socket receptor for a conforming shank 66 of any selectedwork-engaging member,` such as the semi-annular socket 67. The semi-annular shan-k 66 terminates at its ends in radially disposed abutments or. drive shoulders 68, 68 for engagement with hook-shaped abutments or shoulders 69, 69 formed on the ends of the hub 45, as shown in Figures 2 and 3, whereby upon rotation of the hub 45 in either direction the shank 66 of the socket 67will be positively rotated.

The concavesurface 65 of the hub 45 is provided between its ends with a spring pressed ball detent 70 arranged for retaining engagement with a4 complementary recess 71 provided in the socket shank 66 so as to prevent axial displacement of the socket 67 relative to the huby 45 when in place therein.

Referring nowy to Figures 9 and i0 of the drawings, themodified form ofthe invention shown` thereinand gen-v erally designated B, operates like form A, but differs from form A described hereinabove in the structure of the housing 75.. Instead of the. housing 75 being corn.-v posed of two similar housing sections, the housing 75; is composed of a relative deep lower or load bea-ring.

housing section .77, and an upper or retaining housing section 76 which serves as a cover for the open upper end of the lower section 77. Further, 'the actuating shaft bearing enclosure 87 of the modified form B is formed entirely on the lower housing section 77.

The upper or cover housing section 76 comprises a flat plate `88 which in plan shape is substantially like the web Y18 of the upper housing section 76 of the first described form of the invention, and conformably ts into the open upper end 89 of the lower housing section 77. The plate 88 has a depending enlargement 90 in its underside which bears upon the top surface of the ratchet pawl carrier plate 41, as shown in Figure '10. The cover plate 88 is held down in place by fasteners 23 engaging the lower housing section 77.

I claim: l l. In a wrench, a head comprising a housing provided with an opening for accommodating a work-engaging element, said housing being hollow and composed of a retaining section and a load bearing section, means securing said sections together in superimposed relation, said load bearing section being hollow and having an open side facingrsaid retaining section with the retaining section closing said open side, a shear fiange on said load bearingsection, said shear fiange being arcuate and extending around said opening, a rotary hub having a portion within said housing and operatively engaging said shear ange and a portion exposed in said opening for operative engagement with a work engaging element located in said opening, said retaining section, having a portion sIidably engaging said hub, and serving to hold said hub in engagement with said shear iiange, and actuatingmeans on said housing and operatively connected to said hub for rotating the hub along and relative to said shear liange.

2. A wrench'according to claim 1 wherein said retaining section is hollow and has an open side facing said load bearing section.

3.`A wrench according to claim l wherein said retaining section is hollow and has an open side facing said load bearing section, said retaining and load bearing sections being substantially similarly shaped stampings.

4. A wrench according to claim 1 wherein said actuating means comprise an actuating shaft extending radially with respect to the housing and projecting from the housing, at least one of the sections having a radial extension defining a bearing enclosure, and a bearing confined within said bearing enclosure and supportably surrounding saidactuating shaft.

5. A wrench according to claim 1 wherein said actuating means comprise an actuating shaft extending radially with respect to said housing and projecting from the housing, s aid retaining section and said load bearing section having registered extensions together defining a bearing enclosure, a bearing confined in said enclosure and supportably surrounding said actuating shaft.

6. A wrench according to claim l wherein said actuating means Vcomprise an actuating shaft extending radially with respect to said housing and projecting from the housing, said load bearing section having a tubular extension defining a bearing enclosure, a bearing confined in said enclosure and supportably surrounding said actuating shaft.

7. In a wrench, a head having a work receiving opening, a hub on said head,r guide means on said` head confining said hub to movement in a fixed path around said opening, said hub having a row of ratchet teeth, a carrier plate mountedy on saidl head for movement along said row of ratchet teeth in aplane parallel to that in which said hub moves, at least one ratchet pawl pivoted on said carrier plate, first spring means acting between said carrier plate and said ratchetv pawl and yieldably engaging said ratchet pawl with said rowvof ratchet teeth, a camfollower on said carrier plate, an actuating shaft journalled on said head, a vrotary cam fixed on said actuating shaft and engaging said cam follower, second spring means acting between said head and said carrier plate and urging said carrier plate in a direction to keep said cam follower engaged with said rotary cam, said actuating shaft and said rotary cam being positioned with their axes in planes parallel to the plane in which the carrier plate moves, and means connected to said actuating shaft for rotating said shaft in a direction to move said hub around said opening.

8. In a wrench, a housing having a work receiving opening, a hub mounted on said housing for movement around said opening in an arcuate path, ratchet teeth formed on said hub, said ratchet teeth being arranged in an arc, a carrier mounted on said housing for movement relative to said hub in a path substantially concentric with the arc of the ratchet teeth on the hub, at least one spring pressed ratchet pawl pivoted on said carrier and engaging the arc of teeth on the hub, a cam follower on said carrier, a rotary cam mounted on said housing and engaging said cam follower, and means for rotating said cam. v

9. In a wrench, a head having a work receiving opening, a hub mounted on said housing for movement around said opening, said hub having a row of ratchet teeth thereon, a carrier mounted on said head for movement relative to said hub and along said row of ratchet teeth, said carrier having at least one spring pressed ratchet pawl thereon engaging said row of teeth, a'cam follower on said carrier, a rotary eccentric cam mounted on said head and engaging said cam follower, return spring means acting between said carrier and said head serving to hold the cam follower yieldably engaged with said rotary cam, and an actuating shaft journalled on said head and carrying said rotary cam, said shaft and rotary cam being positioned in planes parallel to the plane in which said carrier moves.

10. ln a wrench, a head comprising a hollow housing comprising two similar sections involving websand peripheral, lateral flanges on the webs, means securing the sections together with their lateral anges registered and abutted so as to dene sidewalls extending between said webs, said sections having concave extensions on one end thereof which are in registry and dene a hollow bearing enclosure, the end of said housing remote from said bearing enclosure being formed with a work receiving opening, a rotatable hub having a gripping portion outside of said housing and another portion projecting into the interior of the housing, guide means on said sections engaging said other portion and confining said rotatable hub to a predetermined path of movement around said opening, said other portion of said hub having a row of ratchet teeth thereon on the side thereof remote from said gripping portion, a carrier plate within said housing, means confining said carrier plate to movements along said row of ratchet teeth in a plane located between and parallel to the webs of the sections, at least one ratchet pawl pivoted on said carrier plate, rst spring means acting between carrier plate and said housing and urging said ratchet pawl into engagement with said row of ratchet teeth, a cam follower on said carrier plate, a bearing enclosed in said bearing enclosure, a rotary actuating shaft extending through said bearing and into the interior of the housing, an eccentric rotary cam fixed on the part of the actuating shaft within the housing, said cam being engaged with said cam follower, spring means acting between said carrier plate and said housing and maintaining said cam follower yieldably engaged with said rotary cam, said bearing and said actuating shaft being positioned with their axes parallel to the webs of the sections and normal to the housing sidewalls.

Cir

ll. In a ratcheting wrench, a head comprising a hollow housing provided with an opening for accommodating a work engaging element and with a slot in one end of the housing communicating with said opening toA admit a ywork-piece into said opening, a tubuiar bearing enclosure projecting radially outwardly from the other end of the housing, a bearing enclosed in said enclosure, a rotary actuating shaft extending axially through said bearing and having one end within said housing, a rotary eccentric cam on said one end of the shaft, a carrier plate mounted Within said housing for movement in an arc substantially concentric with said opening, spring pressed, ratchet pawls pivoted on said carrier plate, a cam follower on saidicarrier plate engaging said rotary cam, spring means acting between said carrier plate and said housing serving to maintainV constant engagement of said cam follower with said Vro'- tary camysaid housing having spaced parallel webs including a retaining web and a load bearing web between which said carrier plate is positioned, a semiannular rotary hub positioned Within and concentric to said opening, said hub having an arcuate portion positioned in the housing between said webs, said arcuate portion having sides spaced from said webs, the

side of said arcuate portion adjacent to said retainingA web being provided with an arcuate guideV groove and said carrier plate having a guide ilange' positioned in said guide groove, said retaining web being engaged with` said carrier plate and coniining said guide ange in said' guide groove, the side of said arcuate portion adjacent to the load bearing web being provided with an arcuate load bearing groove, said load bearing web having an arcuate shear flange engaged in said load bearing groove, said load bearing web beingV engaged with the adjacent side of said arcuate portion, said arcuate shear flange being concentric with and extending around said opening, and ratchet teeth on the side of said arcuate portion of the hub adjacent to said carrier plate with' I which said ratchet pawls are operatively engaged.

i2. A ratcheting wrench according to claim 11 where,-

in said housingis composed ofa load bearing sectionl .Y containing said load bearing web and a retaining section containing said retaining web, and said bearing enclosure comprises registered extensions on said sections.

13. A ratcheting wrench according to claim 1l wherein said housing is composed of Va load bearing section containing said load bearing web and said arcuate shear flanges and a retaining section containing said retaining web, and said bearing enclosure consists of a tube xed on said load bearing section.

14. A wrench of the type described, comprising: a I

head; a hub; support means for mounting said hub o n said head for rotative movement; an annular series of ratchet teeth formed onisaid hub; a pair of oppositely directed pawl means; a carrier member mounted for arcuate movement on said head in a path concentric with said annular series of ratchet teeth; means for pivotally mounting said pawl means on said carrier for `engagement with said ratchet teeth;A an eccentric rotary cam mounted on said housing and engaging said carrier; and means for rotating said cam whereby said carrier is arcuately moved to cause said pawl means,

-.l' engaged with the ratchet teeth, to rotatably drive said Y hub. i

l5. A wrench, comprising: a housing having a wor receiving opening; a hub rotatable in said housing, said Y.

to be mounted on said hub; means forming a driving-- connection between the nut engaging member and said hub, whereby said member is rotatably driven with said hub; a plurality of ratchet teeth circumferentially formed on said hub; a pawl carrier mounted on saidV housing for arcuate movement in a path substantially concen- Y n' tric with said circumferential ratchet teeth; a pairiof l pawl means carried by said pawl carrier spaced cir- 1 cumferentially of said hub and engageable with said ratchet teeth; and means including an eccentric cam engaging said carrier for intermittently moving said pawl carrier in opposite directions along said arcuate path whereby said pawl means alternately operates to drive said hub.

16. A wrench of the type described, comprising: a head having a work receiving opening; a hub; means carried by said hub and interengaging with means of said head for mounting and supporting said hub on said head for rotative movement; a replaceable nut en gaging member; means for mounting said nut engaging member on said hub for rotative movement therewith; an annular series of ratchet teeth formed on said hub; a pair of oppositely directed pawl means; a carrier member mounted for arcuate movement on said head in a path concentric with said annular series of ratchet teeth; means for pivotally mounting said pawl means on said carrier; resilient means holding said pawl means in engagement with said ratchet teeth; an eccentric rotary cam mounted on said housing and engaging said carrier; and shaft means adapted to be connected to a power source for rotating said cam whereby said carrier is arcuately moved to cause said pawl means, engaged with the ratchet teeth, to rotatably drive said hub and the nut engaging member mounted thereon.

17. A wrench of the type described, comprising: a head; a hub; support means for mounting said hub on said head for rotative movement thereon; an annular series of ratchet teeth formed about the periphery of said hub; a carrier member; means on said carrier member coacting with means on said hub for mounting said carrier member for arcuate movement within said head in a path concentric with said annular series of ratchet teeth; at least one pawl mounted for pivotal movement on said carrier member; a spring element holding the pawl in engagement with said ratchet teeth; and means including an eccentric cam engaging said carrier member for intermittently moving said carrier member in opposite directions along said arcuate path whereby the pawl engaged with the ratchet teeth rotatably drives said hub.

References Cited inthe file of this patent UNITED STATES PATENTS Fish` Dec. 18,

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