US3621739A

US3621739A - Reversible tool drive

Info

Publication number: US3621739A
Application number: US57950A
Authority: US
Inventors: Wendell Seablom
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-07-24
Filing date: 1970-07-24
Publication date: 1971-11-23
Anticipated expiration: 1988-11-23

Abstract

THIS INVENTION RELATES TO A SOCKET WRENCH DRIVE CHARACTERIZED BY A REVERSIBLE ONE-WAY CLUTCH WHEREIN A ROTATABLE CYLINDRICAL MEMBER IS RELEASABLY LOCKED WITH A CENTRAL CAVITY IN THE HEAD FOR CONJOINT ROTATION BY ROLLERS WEDGED BETWEEN THE CYLINDRICAL MEMBER AND A CAM SURFACE AT THE END OF A RADIAL RECESS OPENING ONTO SAID CAVITY. SPRING ELEMENTS ARE RELEASABLY HELD AGAINST THE ROLLERS BY A CONTROL RING TO BIAS SAME IN EITHER A "FORWARD" OR "REVERSE" POSITION.

Description

1971 w. SEABLOM REVERSIBLE TOOL DRIVE Filed July 24, 197 0 INVENTOR. WENDELL SEABLOM vwvs ATTORNEYS United States Patent 3,621,739 REVERSIBLE TUOlL DRIVE Wendell Seablom, 316 S. 138th St, Tacoma, Wash. 98444 Filed July 24, 1970, Ser. N0. 57,950 Int. Cl. 1325]) 13/00, 13/46 US. Cl. 81--59.1 13 Claims ABSTRACT OF THE DISCLOSURE Socket wrench drives of one type or another are notoriously old in the art, most of them utilizing some form of the ratchet-and-pawl principle. While certainly quite simple in construction, this type of wrench has the disadvantage of having to be reversed a discrete angle to engage the next notch of the ratchet-and-pawl mechanism. Also it is rather susceptible to wear during heavy use such as it would ordinarily be subjected to in a shop or garage. Other types are less sensitive to wear on the Working parts but, at the same time, they involve complex and costly one-way clutches that make the unit expensive as well as subject to malfunction for other reasons than wear.

Head size is another disadvantage of the prior art socket wrenches in that many are either too thick or overly wide to fit into hard to reach places. Ideally, one would like to be able to fit a socket wrench into all places where an end wrench would fit and, since this is virtually impossible due to the space required for the operating mechanism, the best that can be done is to approach this condition.

The socket wrench drive presently disclosed and claimed has the advantage of being continuously engageable over the entire 360 of rotation. This means that in hard to reach places a fastener can be turned very small increments on each stroke or that full advantage may be made of the space available without having to reverse the stroke a discrete engaging notch of the wrench drive.

The socket wrench drive of the instant invention has the further advantage of extreme simplicity Without sacrificing its functionality. The parts are few in number and quite simple to fabricate; yet, their design is such that they are extremely rugged. Case-hardened steel rollers wedged between cam surfaces at the bottom of the recesses and the similarly hardened surface of the central rotating member bear the torque loads with little wear. If parts need to be replaced or repairs made, removal of the cover enables one to completely disassemble the unit with only a small screwdriver. Even compact versions of the unit having rollers of minimal diameter and a thin-walled case bordering the cam-surfaced recesses will ordinarily withstand torque loads several times greater than that which will shear off the bolt or other fastener to which the tool is applied.

The reversing mechanism is simplicity itself in that pairs of coil springs engage opposite sides of each roller and, depending upon the position of the control ring, bias the rollers toward one side of the cam surface or the other. These springs carry none of the torque load and, for this reason, are very light. The non-biasing springs cooperate with the control ring to hold it in either its forward or reverse position.

3,621,739 Patented Nov. 23, 1971 It is, therefore, the principal object of the present inven tion to provide a novel and improved socket wrench drive.

A second objective of the invention forming the subject matter hereof is the provision of a socket wrench having a reversible one-way clutch of unique design.

Another object of the invention herein disclosed and claimed is the provision of a one-way clutch mechanism based upon a wedged-roller locking arrangement whereby the clutch is continuously engageable over the entire 360 of rotation.

Still another objective is to provide a socket wrench drive wherein the one-way clutch is shifted by a simplified forward-reverse actuator.

An additional object is the provision of a socket wrench drive that locks more securely on the work piece as the torque load increases.

Further objects of the invention are to provide a socket wrench drive that is easy to operate, rugged, wear-resistant, compact, reliable, simple to service and repair, versatile and even somewhat decorative.

Other objects will be in part apparent and in part pointed out specifically hereinafter in connection with the description of the drawings that follows, and in which:

FIG. 1 is a side elevation view of a socket wrench employing the herein described reversible drive;

FIG. 2 is a fragmentary section to an enlarged scale taken along line 22 of FIG. 1 showing the rollers in a position for tightening a right-hand thread fastener;

FIG. 3 is a view substantially identical to FIG. 2 except that the control ring is shown in a position to shift the rollers into a position for tightening a left-hand thread fastener;

FIG. 4 is a view substantially identical to FIG. 2 except that the control ring is shown in. a position to shift the rollers into a centered or neutral position; and

FIG. 5 is a fragmentary section view taken along line 5-5 of FIG. 4 with the cover plate shown in position.

Referring next to the drawings for a detailed description of the present invention and, initially, to FIG. 1 for this purpose, reference numeral 10 has been chosen to broadly designate the socket wrench drive in its entirety while numeral 12 refers specifically to the handle thereof and numeral 14 to the head on one end of said handle. The head 14 has a tool holder 16 of rectangular cross section projecting through an essentially flat planar cover plate 18 thereof, while the control ring 20 which functions as the reversing actuator completely encircles the top portion of the head 14.

The handle 12 in the manner of most socket wrench drives is straight and includes a checkered end portion 26 to provide a better hand grip. The head 14, on the other hand, comprises a shallow generally cylindrical enlargement with tool holder 16 projecting upwardly from the center thereof and through cover plate 18.

Next, with reference to FIGS. 2-5, inclusive, the details of the reversible one-way clutch assembly that has been designated broadly by reference numeral 30 and which is housed in the head 14 will be set forth in detail. The head contains a centrally-located generally cylindrical cavity 32 having, in the particular form shown, three equiangularly-spaced radial recesses 34 radiating therefrom that terminate in concave cam surfaces 36. This central cavity is terminated at the bottom by the inside face 24 of the head 14 and is open at the top of head 14 and adapted to receive cover plate 18.

Seated within the bottom of this cavity 32 is a rotating element 40 which includes a cylindrical portion 42 freely rotatable within said cavity and having the tool holder 16 projecting axially therefrom as an integral part thereof. Rotating element 40 is partially held in position by a cylindrical axial extension 43 on the bottom thereof which fits into guide hole 45 bored in the inside face 24 of the central cavity. Cylindrical portion 42 of the rotating element 40 cooperates with cylindrical rollers 44 seated in the bottom of the radial recesses 34 and the cam surfaces 36 at the base of the latter to define the one-way clutch 30, the operation of which will be described in detail presently.

Surrounding the central cavity is the upstanding annular side wall 46 of the head 14. The cover plate 18 with central aperture 50 fits onto the top of this side wall and is held in place by machine screws 52. The outside of side wall 46 is reduced in diameter around its top portion leaving a flange 54 formed by the bottom portion of head 14. Control ring 20 then encircles this outside wall, rests on flange 54, and is held in place by cover plate 18 which is sized large enough to extend out over the control ring.

Each of the cylindrical rollers 44 seated in the radial recesses are acted upon by a pair of biasing elements which operate on substantially opposite sides thereof and tend to urge the rollers in opposite directions around the rotating element 40. In the particular embodiment shown these biasing elements are coil springs 56 which fit into passages 58 drilled through the head side wall which are equally spaced around the central cavity and essentially parallel to lines tangent to the cylindrical portion of rotating element 40. The passages thus form openings from the radial recesses 34 which terminate in holes 60 in the outside of side wall 46. The coil springs are fitted on the outside end with a bearing cap 62 and are inserted into the passages so that the uncovered end bears against the rollers 44. The springs are of a length which causes the rollers to be equally biased on both sides when the bearing cap of each spring is flush with the outside of the side wall.

Control ring 20 is constructed with its inside surface having three equiangularly-spaced pockets 64 adapted to register with corresponding holes 60 of each roller-biasing mechanism and relieve three of the corresponding biasing springs when so registered. It will be noted that the control ring is limited in its rotational movement by the stopping action of the following edges 65 of the pockets acting against the bearing caps 62 which protrude into the pockets. When the control ring is in a position so that the pockets are not aligned with any of the holes 60, the bearing caps 62 are all held inside the periphery of the head side wall and each pair of springs pushes against the rollers with equal force thereby tending to hold them in a neutral position as shown in FIG. 4. A shift in the control ring from the neutral position of FIG. 4 into one or the other of the actuated positions of FIGS. 2 or 3 will relieve the lead element of each pair of springs while causing the following element to push the roller ahead thereof inwardly along the cam surface to a position where it begins to wedge between the latter surface and the cylindrical bearing surface 42 of the rotating element. Once this occurs, the one-way clutch 30 engages to lock the rotating element 40 within the head 14 for conjoint rotation in the direction opposite to that in which the rollers are are biased, i.e., in the direction of the arrows in FIGS. 2 and 3. In other words, in FIG. 2, the tool holder (not shown), which projects upwardly, will presumably be fitted with a socket that is, in turn, engaged with a work piece which resists rotation; therefore, counter-clockwise motion of the head 14 will act to roll the rollers 44 counterclockwise also and they will tend to clamp further up the cam surface and wedge even more tightly against the rotating element. The opposite is, of course, true of the operation of the one-way clutch in the reverse position of FIG. 3.

Again, with reference to FIG. 2, when the head is turned clockwise, the action of the rollers will be such as to roll down the cam surface toward the neutral position of FIG. 4 thus withdrawing the wedge formed thereby and releasing the rotating element 40 to remain in fixed position while the head 14 turns, as aforesaid, clockwise relative thereto.

The cam surfaces 36 must, obviously, be concave and have a radius of curvature substantially greater than that of the rollers 44. These surfaces are preferably symmetrical on opposite sides of a radial line passing through the midpoint thereof. Most important, of course, is that the neutral area 66 of the cam surface located approximately midway between the ends thereof be spaced away from the bearing surface 42 of the rotating element a distance greater than the diameter of the roller 44 that moves therebetween. Of equal importance is that the end portions 68 of the cam surface on opposite sides of the neutral area 66 gradually approach the bearing surface 42 of the rotating element until the distance separating the latter is less than the diameter of the roller 44. A cylindrical cam surface works quite well for the purposes of the present invention although the preferred form thereof is to make both end portions 68 thereof cylindrical surfaces of essentially the same radius of curvature but separate them by a flattened neutral area of a greater radius of curvature or even a planar surface.

As illustrated, the clutch subassembly 30 includes three radially-disposed recesses located apart and this is the preferred number; however, it is obvious that more than three can be used although no particular advantage exists in so doing and the unit becomes more complicated and expensive. On the other hand, two diametricallyplaced recesses could probably be made to workas, for that matter, could a single one; however, in so doing, a portion of the bearing surface of the rotating element would have to bear directly against the wall of the central cavity which is not designed to resist the type of sliding contact occasioned by each retraction stroke as opposed to the work stroke where little relative motion takes place.

Another rather obvious modification is to substitute balls for the rollers 44. Here again, while this would surely work, to do so results in a concentration of the torque loads at three points rather than spreading these loads out along lines extending the length of each roller as has been done here. Accordingly, the roller construction shown is preferred.

Furthermore, the biasing elements can take many alternative forms, such as leaf springs, torsion rods, or even coil springs under tension, without departing from the basic teaching of the present invention. Also the disclosed drive could be made non-reversible, and thereby simplified, by deleting all of the biasing elements on corresponding sides of each roller. While all of these modifications are possible and may be practical in certain applications, the embodiment shown and described is the preferred one.

I claim:

1. The reversible tool drive which comprises: handleforming means; a head rigidly connected to the handleforming means for rotation therewith, said head including a tool-receiving cavity in one face thereof adapted to accept the cylindrical body portion of a tool for rotation therein, at least three concavely arcuate cam-forming recesses opening radially inward onto the cavity, an outwardly-facing generally-cylindrical control ring track encircling the recesses and cavity, and chordal biasing element passages extending from opposite sides of each camforming recess onto the adjacent surface of the control ring track; a tool having a cylindrical body portion mounted in the tool-receiving cavity for rotational movement in either direction about its own axis, said tool having means projecting axially from its cylindrical portion adapted for releasable connection to a Work piece or another tool; roller means mounted in each recess in tangential contact with the arcuate surface of the latter and the cylindrical body of the tool, said roller means c0- operating with their respective arcuate cam surfaces to define a centrally located neutral position adapted to permit free rotation of the tool means in either direction, and said roller means cooperating with their respective cam surfaces on both sides of said neutral position to define a pair of operative positions, one of said operative positions permitting free relative clockwise rotation of said tool while locking the latter against relative counterclockwise rotation, and the other of said operative positions permitting free relative counterclockwise rotation thereof while locking same against relative clockwise rotation; shiftable spring-biased detents mounted in each chordal passage bearing against opposite sides of their respective rollers, opposed pairs of said detents cooperating with one another in one position to exert an unequal bias on each of the rollers in a clockwise direction and in a second position an unequal bias on each of said rollers in a counterclockwise direction, all of the detents on one side of their respective rollers defining a first set thereof while the detents on the other side define a second set; and, means comprising a control ring mounted on the cylindrical track for both clockwise and counterclockwise rotation relative thereto, said ring including on the inner surface thereof first and second sets of cam surfaces; said first set of cam surfaces being positioned and adapted in one operative position of said ring to simultaneously actuate the first of detents so as to bias the rollers clockwise and said first set of cam surfaces being positioned and adapted in a second operative position of said ring to simultaneously actuate the second set of detents so as to bias said rollers counterclockwise and said second set of cam surfaces in the first operative position of said ring being positioned and adapted to cooperate with the first set of cam surfaces so as to simultaneously release said second set of detents into their deactivated positions and in the second operative position of said ring to similarly release the first set of detents into their deactivated positions.

2. The reversible tool drive as set forth in claim 1 in which: a centrally-apertured cover plate is removably attached to the head and is sized to cooperate therewith so as to hold the control ring, detents, rollers and tool means in assembled relation.

3. The reversible tool drive as set forth in claim 1 in which: the rollers are cylindrical.

4. The reversible tool drive as set forth in claim 1 in which: the arcuate cam-forming recesses are equiangularly-spaced around the cavity.

5. The reversible tool drive as set forth in claim 1 in which: the arcuate cam-forming recesses are substantially cylindrical.

6. The reversible tool drive as set forth in claim 1 in which: there are three concavely arcuate cam-forming recessess opening inward onto the cavity.

7. The reversible tool drive as set forth in claim 1 in which: the cam surfaces in the inner surface of the control ring are adapted and located whereby the control ring can be rotated to a position holding both sets of detents in an actuated position to exert substantially equal forces on each side of the rollers thereby allowing the tool means to freely rotate in either direction.

8. The reversible tool drive as set forth in claim 1 in which: the spring-biased detents each include a coil spring having a bearing surface on each end with one end in engagement with the roller and the other end projecting sufficiently outwardly in the said chordal passage to engage the said first set of cam surfaces.

9. The reversible tool drive as set forth in claim 1 in which: the spring-biased detents each include a coil spring in engagement with the roller and a pin projecting sufficiently outwardly in the said chordal passage to engage the said first set of cam surfaces.

10. The reversible tool drive as set forth in claim 11 in which: the set of detents in the deactivated position cooperative with the second set of cam surfaces to form a stop limiting the rotation of the control ring.

11. The reversible tool drive as set forth in claim 1 in which: the axes of the chordal biasing element passages extending from opposite sides of each cam-forming recess are substantially collinear along a line passing through the roller and parallel to a line tangent to the cylindrical body portion of the tool means.

T2. The reversible tool drive as set forth in claim 1 in which: the axes of the chordal biasing element passages extending from opposite sides of each cam-forming recess are substantially collinear along a line passing through the roller and perpendicular to a line through the axis of rotation of the tool means and the center of the roller when said roller is in the centrally-located neutral position.

13. The reversible tool drive as set forth in claim 1 in which: the axes of the chordal biasing element passages extending from opposite sides of each cam-forming recess are substantiallly collinear along a line passing through the center of the roller when said roller is in the centrally located neutral position and perpendiculatr to a line through the axis of rotation of the tool mean and the center of the roller when said roller is in said centrallylocated neutral position.

References Cited UNITED STATES PATENTS 2,119,622 6/1938 Freber 8159.1 X 3,362,267 1/1968 Rozmus 81-59.1 2,584,256 2/1952 Brown 81-591 X FOREIGN PATENTS 1,121,260 2/1956 France 19212 B JAMES L. JONES, Jr., Primary Examiner US. Cl. X.R.