US3149707A - Ratchet adapter for torque-applying tool - Google Patents

Description

P 1964 A. M. MOINNIS v 3,149,707

RATCHET ADAPTER FOR TORQUE-APPLYING TOOL Filed June 1961 2 Sheets-Sheet 1 Sept. 22, 1964 A. M. MOINNIS RATCHET ADAPTER FOR TORQUE APPLYING TOOL 2 Sheets-Sheet 2 Filed June 2, 1961 INVENTOR. Awoeaw M Mt/NN/J United States Patent 3,149,707 RATCHET ADAPTER FGR TORQUE- APPLYING T6012 Andrew M. Mcl'nnis, West Covina, (Ialih, assignor, by mesne assignments, to Pendleton Tool Industries, Inc,

Los Angeles, Calit., a corporation of Delaware Filed June 2, 1961, Ser. No. 114,413 1 Claim. (Cl. 192-43.1)

This invention relates generally to torque-applying tools which ratchet and, particularly, with improved ratchet means for such tools.

Ratcheting torque-applying tools which are designed for low torque applications generally utilize but one ratchet pawl. This single ratchet pawl engages the ratchet teeth without difiiculty to condition the tool for transmission of a torque to a workpiece.

Torque-applying tools designed for high torque applications, on the other hand, must employ two ratchet pawls in order to reduce the load on each pawl and its engaged ratchet tooth to a safe value. In ratcheting tools of this type, both ratchet pawls must be properly engaged with the ratchet teeth during the application of a torque load. Otherwise, if only one ratchet pawl were engaged, an excessive load would be transmitted through this pawl and its engaging ratchet tooth which would possibly cause shearing of the ratchet tooth. If this happens, the handle of the torque-applying tool is suddenly released with the result that the user of the tool may incur injury. Moreover, in most cases, the ratchet teeth are marred beyond repair.

The manufacturing tolerances in dual pawl ratcheting tools are such that the ratchet teeth adjacent one pawl may be properly aligned to permit that pawl to drop into engagement with the teeth while the ratchet teeth adjacent the other pawl may be slightly misaligned so that the latter pawl is held out of engagement with the teeth. Under these conditions, the engaged ratchet tooth may shear, as just discussed.

A general object of this invention is to provide an improved dual pawl ratchet means for ratcheting torqueapplying tools, which ratchet means is so constructed and arranged as to insure that both ratchet pawls will be properly engaged with the ratchet teeth before a torque load is applied, whereby shearing of the ratchet teeth due to engagement of only one ratchet pawl is prevented and the possibility of injury to the user of the tool is eliminated.

Another object of the invention is to provide a dual pawl ratcheting means of the character described which is sim- Other objects, advantages, and features of the inventron will become readily apparent as the description proceeds.

Briefly, the objects of the invention are attained by providing a ratchet means equipped with an outer driving part or body to be rotated and an inner driven part or rotor, having ratchet teeth, rotatably fitted in a bore in the body. Formed in the body are two diametrically opposed, axially extending, semicircular recesses in which are fitted, respectively, two semicylindrical ratchet pawls. These pawls are spring loaded into engagement with the ratchet teeth, in the known way, to provide a reversible ratcheting action.

The invention resides in providing the flat faces of these pawls with upstanding ribs engageable by the ratchet teeth. During ratcheting movement of the body and rotor,

the ratchet pawls are held out of engagement with the ratchet teeth, by engagement of the latter with the pawl ribs, until the ratchet teeth clear the ratchet pawls. The

dddhfi? Patented Sept. 22., 1964 ratchet pawls are then released to drop into engagement with the ratchet teeth. In this way, the ratchet teeth must clear the ratchet pawls before the latter are released for engagement with the teeth so that proper engagement of both ratchet pawls with the ratchet teeth is assured.

The rotor has a slight loose fit in the body. If, by some possibility, one ratchet pawl is held out of engagement by the ratchet teeth when the other drops into engagement, and a torque load is applied to the outer driving part, the inner driven part rocks in such a way as to positively clear the disengaged pawl and release the latter for engagement with the ratchet teeth.

A better understanding of the invention may be had from the following detailed description thereof, taken in connection with the annexed drawings, wherein:

FIG. 1 is a perspective View of a ratchet adapter embodying the present improved ratchet means;

FIG. 2 is a section taken along line 2-2 in FIG. 1;

FIG. 3 is a section taken along line 3-3 in FIG. 2;

FIG. 4 is a section taken along line 4-4 in FIG. 2;

FIG. 5 illustrates one ratchet pawl of the present ratcheting means in one position of engagement with the ratchet teeth;

FIG. 6 illustrates the ratchet pawl of FIG. 5 in its other position of engagement with the ratchet teeth;

FIG. 7 is a perspective view of the ratchet pawl;

FlG. 8 is a perspective view of a ratchet pawl reversing spring which is used in the present ratchet means; and

FIGS. 9-13 illustrate the actions which occur during ratcheting of the present ratchet means.

The illustrated ratchet adapter 10 comprises an outer cylindrical part or body 12. Extending into one end of this body is a flat-bottomed bore 14- which defines, at the other end of the body, an end wall 16. Extending from this end wall, coaxially with the body 12, is a cylindrical extension 18. This extension has a square socket or recess 26 extending through it from its upper end for receiving a square stud 22 of a non-ratcheting wrench 24. The present ratcheting adapter 10, then, provides the nonratcheting wrench 24 with a ratcheting action.

Rotatably received within the bore 14 of the body 12 is an inner driven part or rotor 26 of the adapter. This rotor has, within the bore 14 of the body 12, an enlarged, generally cylindrical end 28 which is formed about its periphery with ratchet teeth 30. The outer diameter or" these ratchet teeth is slightly less than the diameter of the bore 14.

Below its enlarged cylindrical end 28, the rotor 26 is formed with a reduced coaxial, smooth, cylindrical shoulder 32. This shoulder extends through a central hole 34 in a retainer disc or plate 36 fitted in the open end of bore 14. The opening 34 in the plate 36 has a diameter which is slightly greater than the diameter of the shoulder 32. Rotor 26 is completed by a square stud 38 below the shoulder 32 for receiving a wrench socket, for example. The stud is provided with a spring-pressed locking ball til.

Body 12. is formed internally with two diametrically opposed, generally semicylindrical recesses 42. Plate 36 has diametrically opposed lobes or tongues 44 which fit in these recesses tolock the plate 36 against rotation and close the ends of the recesses. A snap spring 46, fitted in an internal groove in the wall of bore .14, locks the plate 36 in the body.

Loosely and rotatably fitted within the recesses 42 of the body 12 are two generally semicylindrical ratchet pawls 48. As shown best in FIG. 7, each ratchet pawl 43 comprises a semicylindrical end 50 which is cut away at its upper end to provide the pawl with a slender upper extension 52. The flat chord face of the pawl has a rounded, upstanding central rib or lobe 54 which extends the length of the pawl, as shown. The intersection of the chord face of each pawl with the cylindrically curved surface of the pawl defines a pair of axially extending teeth 4.8T on each pawl.

The semicylindrical recesses 42 of the body 12 extend through the end Wall 16. Resting on the upper surface of this end wall, and rotatably fitted on the cylindrical extension 18 of the body, is a washer 56 (FIG. 3). This washer has two diametrically opposite, radially extending slots 58. Resting on the top of the washer 56 is a curved spring 60 (FIG. 8). Spring 6% has a semicircular part 62 and two downwardly bent ends 64. The ends 64 of the spring 60 extend through the washer slots 58 into the upper ends of the recesses 42 in the body 12 and engage behind the reduced ends 52 of the pawls 48, which ends are located in the upper ends of the body recesses 42. The pawls are urged toward the ratchet teeth 30 by the spring 60.

As shown in FIGS. and 6, when an end 64 of the spring 66 engages the pawl extension 52 at one side of the center line of the pawl, the latter is rotated in one direction to engage one pawl tooth 53T with the ratchet teeth 30 to lock the rotor 26 against rotation in one direction in the body 12. In FIG. 5, for example, the rotor 26 is locked against counterclockwise rotation in the body 12 by the pawl 48 but is permitted to rotate in the clockwise direction past the pawl. As each ratchet tooth 39 moves past the pawl, of course, the latter rocks in the counterclockwise direction against the action of the spring end 64 and snaps in behind the ratchet tooth, which action is repeated for each ratchet tooth as it rotates past the pawl. When the direction of the rotor is changed, the pawl again engages behind a ratchet tooth 30 to lock the rotor 26 against counterclockwise rotation in the body.

When the spring end 64 is shifted to a position of engagement with the pawl extension 52, at the opposite side of the axis of rotation of the pawl, the latter is rotated to its position of FIG. 6 wherein the other pawl tooth 58T engages the ratchet teeth 30 to lock the rotor 26 against clockwise rotation in the body 12 and permits counterclockwise ratcheting movement of the rotor in the body.

The above discussion applies to the other ratchet pawl, of course.

Referring now to FIG. 4, it will be observed that the pawl spring ends 64 are arranged to position their pawls in corresponding positions so that in the pawl positions illustrated in FIG. 4, for example, the rotor 26 can rotate in the clockwise direction in the body 12 but is restrained, by both pawls 48, against rotation in the counterclockwise direction in the body 12.

The pawl spring ends 6 5- can be shifted from one side to the other side of their respective pawls, to reverse the position of the pawls and thereby the ratcheting direction of the adapter, by rotation of the spring 6t) about the axis of the adapter. To this end, the washer 55 is formed with a radial key as which fits in a notch 68 in a pawlreversing or cover disc '70. In FIG. 2, it will be observed that the washer 56 is slightly smaller in diameter than that of the body 12 and that the cover disc 70 has a cylindrical flange 72 which fits about the outside of the washer and rests against the upper face of the body 12. The notch 68 is formed in this flange '72. The cover disc '70 is locked in position by means of a snap ring '74 which fits in an external groove in the cylindrical extension 18.

From this description, it is evident that rotation of the cover disc 79 rotates the Washer 5e and, therefore, the spring 60 to shift the spring ends 64 from one side of their respective pawls to the other. Thus, the ratcheting direction of the adapter may be reversed by turning the cover disc'7tl in one direction or the other.

The actions which occur during ratcheting of the parts of the illustrated ratchet adapter will'now be described by reference to FIGS. 9-13. In the following discussion, it'will be assumed, for convenience, that the rotor 26 rotates in a counterclockwise direction and the body 12 remains stationary. In actual operation, of course, the

i rotor 26 remains stationary and the body 12 is rotated during a ratcheting action. The relative movements of the parts are the same, however, in both cases.

We start in the position of FIG. 9 wherein one half 48a of the flat chord face of pawl 48 rests fiat against the side face of ratchet tooth 30a. The locking edge 480 of the pawl, defined between the cylindrical pawl surface and the flat pawl face 48a, engages in the space between the pawls. In these positions of the parts, the rotor 26 is restrained against clockwise rotation in the body 12 so that in actual operation, the body would be rotated in a counterclockwise direction to transmit a counterclockwise torque to the rotor 26.

During initial relative ratcheting rotation of the rotor 26 in the counterclockwise direction, the tip of tooth 30a exerts a camming action on the pawl face 48a which rotates the pawl in a clockwise direction against the action of its biasing spring end 64. This camming action and pawl rotation continueduring movement of the parts through the positions illustrated in FIGS. 10 and 11.

As rotor 26 continues to rotate past the position of FIG. 11, ratchet tooth 30a reaches a position at or close to the upper end of the ratchet pawl, as it is viewed in the drawings, wherein the pawl spring end 64 is located to rock the pawl 48 about the tooth 30:: as a center to the position shown in phantom lines in FIG. 11. In this position, the pawl faces 48a and 48b rest flat against the tips of ratchet teeth fitia and 3012. At this time, the tooth 30b is just about to contact the pawl lobe 54 or is just in light contact with the lobe. Continued clockwise rotation of the rotor 26 now forces the ratchet tooth 3012 against the lobe. A camming action is thereby created on the cam, which camming action develops a force having the two force components Pa and Pb. Force component Fa moves the pawl 48 to the right, as viewed in thedrawings, out of contact with the tips of the ratchet teeth 30a and 39b, as illustrated in FIG. 12. The force component Fb forces the pawl upwardly and its upper edge 480 into frictional contact with the surface. of recess 42 in which the pawl is positioned. It will also be observed that the direction line of force component Fb is offset to the left of the point of contact of the upper corner of the pawl with the recess wall. As a result, a moment is created on the pawl tending to rotate the latter in a clockwise direction about the point of contact of the pawl lobe 54 with the surface of ratchet tooth 3% as a center. This moment and the frictional resistance between the upper corner of the pawl and the recess wall resist clockwise rocking of the pawl under the action of the pawl spring end 64.

As a result, as tooth 3% moves past the pawl lobe 54, it cams the pawl 48 to the right and prevents counterclockwise pivoting of the pawl, under the action of its spring end 64, to a position behind ratchet tooth 36a. In FIG. 13, it will be observed that a short time before the tip of ratchet tooth 3% reaches a position on the center line of the pawl lobe 541, which position mustbe reached before the pawl is released for rocking toward the ratchet teeth under the action of its spring 64, the previous ratchet tooth 315a is just starting to move out from under the upper end of the pawl. As a result, when the tip of ratchet tooth finally does reach the center line of the pawl lobe 5e, and releases the pawl, the ratchet tooth 39a is sufiiciently clear of the upper end of the ratchet pawl as to not impede rocking of the latter into engagement with the ratchet teeth. The rotor 26 is then locked against clock wise rotation with respect to the body 12. It is obvious that the above action occurs in both pawls and for each ratchet tooth.

it is'clear, then, that by properly positioning theparts of the present ratchet means, the movement of each ratchet tooth beyond the end of the ratchet pawl, which is necessary before the ratchet pawl is released, may be made suificient'to accommodate all dimensional variations permitted within the manufacturing tolerance of the tool without presenting the possibility of interference between the ratchet teeth and pawl. In the present ratchet means, therefore, the rotor 26 and body 12 must be relatively rotated a distance beyond the position in which the teeth clear the ratchet pawls before the latter are released.

The angular relationship between the pawl lobes 54 and the ratchet teeth is such that if the direction of rotation of the rotor 26 is reversed from ratcheting direction to locking direction at any point between the positions illustrated in FIGS. 913, the pawls will settle back to their original positions. Now, let us assume that upon reaching the position of FIG. 13, one of the pawls drops into engagement behind a ratchet tooth. When this happens, the rotor 26 becomes loose in the body 12, for a brief instant of time, because of the clearance that exists between the rotor and the body. The ratchet teeth on the rotor can now no longer hold the other disengaged pawl in its disengaged position of FIG. 13. As a result, the latter pawl is released and is urged toward the ratchet teeth by its spring 60. Since the presently engaged ratchet pawl is now engaged behind a ratchet tooth, the ratchet teeth adjacent the previously disengaged pawl will be located to receive the latter pawl. The previously disengaged pawl, therefore, is urged into engagement with the ratchet teeth by the action of its spring end 64 to condition the ratchet means for transmission of a torque from the body to the rotor, through the pawls and ratchet teeth, by rotation of the body in the locking direction.

During ratcheting movement of the parts, the ratchet teeth snap by the ribs 54 on the ratchet pawls. This snapping action produces irnpacts which facilitate proper interengagement of the pawls with the ratchet teeth.

Clearly, therefore, the invention herein described and illustrated is fully capable of attaining the several objects and advantages preliminarily set forth.

What is claimed is:

A ratchet adapter comprising:

a body member having a bore opening through one end of said body member,

a rotor member rotatable in said bore and having ratchet teeth about its periphery,

there being two diametrically opposed, generally semicylindrical recesses in the wall of said bore extending parallel to the axis of and opening to said bore,

said recesses opening through said one end of said body member and through the opposite end of the body member,

a retainer disc fixed in said one end of said body member to retain said rotor member in said bore and having lobes closing the adjacent ends of said recesses,

said rotor member having a reduced portion extending rotatably through a central hole in said disc,

a pair of generally semicylindrical ratchet pawls rotatably positioned in said recesses, respectively, each having a first chord face confronting said rotor member and a cylindrically curved surface intersecting said chord face to define a pair of axially extending teeth on each pawl,

said pawls being rotatable in their respective recesses between first positions wherein one tooth of one pawl and one tooth of the other pawl engage said ratchet teeth to lock said body and rotor members against relative rotation in one direction and second positions wherein the other teeth of said pawls engage said ratchet teeth to lock said body and rotor members against relative rotation in the opposite direction,

the end of each pawl adjacent said opposite end of the body member having a second chord face facing in the opposite direction to the first chord face of the respective pawl,

a pawl-reversing disc rotatably mounted on said opposite end of said body member for turning on the axis of said bore,

resilient means engaging said second chord faces of said pawls, respectively, and operatively connected to said pawl reversing disc for rotation between one position wherein said resilient means engage said second chord faces at one side of the pawl axes, respectively, to yieldably urge said pawls to said first position and a second position wherein said resilient means engage said second chord faces at the other side of the pawl axes, respectively, to yieldably urge said pawls to said second position,

said pawls being rotatable in their respective recesses against the action .of said resilient means by a caming action of said ratchet teeth against said first chord faces when said pawls are in said first or second positions whereby to permit relative rotation of said body and rotor members in a direction opposite to the direction in which said pawls prevent relative rotation of said body and rotor members,

means on one of said members for rotating said one member, and

means on the other member for driving connection to an element to be driven.

References Cited in the file of this patent UNITED STATES PATENTS 1,199,738 Ayer Sept. 26, 1916 1,510,059 Holle Sept. 30, 1924 1,854,513 Hummel Apr. 19, 1932 2,020,883 Gagne Nov. 12, 1935 2,544,795 Knudson Mar. 13, 1951 2,583,617 Walraven et a1. Jan. 29, 1952 2,627,330 Gantz Feb. 3, 1953 2,851,914 Zeckzer Sept. 16, 1958

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