US3078973A - Ratchet mechanism - Google Patents

Description

Feb. 26, 1963 L. E.- KILNESS RATCHET MECHANISM 2 Sheets-Sheet 1 Filed June 30, 1961 /0 INVENTOR. LUTHER E. K/L/VE-S'S 1 /8 BY ATTORNEYS Feb. 26, 1963 1.. E. KILNESS 3,

RATCHET MECHANISM Filed June 30, 1961 2 Sheets-Sheet 2 INVENTOR. LUTHER .E. K/LA/E53 BY W 21 ya A TTORNEYS This invention relates to ratchet mechanisms and more particularly to reversible ratchet wrenches.

The primary object of the invention is the improvement of the controls for the pawl shown in my United States Patent No. 2,5 54,990.

Another object is to provide eiiicient coupling between pawls which utilize all teeth for driving in both directions and a manual reverse control.

Still another object is to provide simplified coupling between one-piece reversible pawls carried by the workturning member and pawl shifting elements which may be operatedby a directional manual reverse on the handle.

A further object is to provide reliable and inexpensive pawl controls adapted for use with pawl systems carried by the work-turning member.

Other objects and advantages of the invention will be apparent from the description and accompanying drawings.

In the drawings, FIGURE 1 is a perspective view of a ratchet wrench illustrating the invention and shown in more detail in FTGURES 2 through 5.

FTGURE 2 is a sectional view of the head of the wrench taken on the line 2-2 of FIGURE 5.

FIGURE 3 is a sectional view taken on the line 3-3 of FIGURE 5.

FIGURE 4 is a detail perspective view of a control spring and shift pin.

FIGURE 5 is a vertical section taken substantially through the center of the wrench head.

FIGURES 6 and 7 are transverse and vertical sections respectively of a modification of the invention. FTGURE 6 is taken along the line 6-6 of FIGURE 7.

The embodiment of the invention shown in FIGURES 1 through 5 has a driving member 1i? having a head 11 at one end. The other end of the driving member has a handle grip 12. The head 11 has a cylindrical opening 13 formed with internal ratchet teeth 14. A work-turning member 15 is journalled in the cylindrical opening by small flats on the teeth 14-. A flan e 16 on the workturning member bears against a shoulder in the cylindrical opening 13 for positioning the work-turning member in the opening. The work-turning member 15' is retained in assembly by a split retaining ring 17 which is entered in a groove in the head 11. The work-turning member has a square 18 at one end for holding detachable sockets. A cap or cover plate it? closes the top of the head 11 and is retained by a split ring 2%? which fits inside grooves in the head 11 and the cover plate 19. The ends of the split ring 21') are formed with indentations extending into recesses 21 and 22, in the cover plate 19 to permit assembly and disassembly of the cover plate.

A pawl 23 is carried in a concave recess or chamber 24 on the side of the work-turning member 15. The pawl 23 has an arcuate side with a series of teeth 25 adapted to concurrent and reversible engagement with the teeth 14- in the head 11. The pawl is of smaller size than the recess 24 to permit circumferential displacement of the pawl and withdrawal of the pawl teeth from the teeth 14. The pawl 23 has two oppositely positioned surfaces for transmitting thrust in two directions through or relative to the pawl body to opposing ends of the recess 24. The ends of the recess converge toward each other in a direction away from the teeth 14. The pawl 23 is resiliently held against the teeth 14 by a spring 26 contained in a bore in the pawl Patented Feb. 26, li53 and which pushes outwardly against a ball 27. The ball engages an inner surface of the concave recess 24.

A control plate 28 has an extension 29 on one side which engages pins 3t) and 31 on the pawl 25 for directing the pawl toward either end of the concave recess. The extension 29 is narrower than the spacing between the pins 3% and 31 to permit freedom of movement for the end of the pawl not engaged by the extension. The control plate 28 is positioned in a concentric recess on top of the work-turning member. The inner wall of the concentric recess forms a hub 32 for rotata-bly mounting the control plate. The top of the hub 32 is peened over against a beveled surface on the control plate 28 to hold the control plate in assembly.

The control plate 23 and two control springs 33 and 34 provide resiliently-acting means for biasing the pawl toward a selected end of the recess 24. The resilientlyacting means is employed as a connection or coupling between the pawl and manually adjustable controls, as hereinafter described. The control plate 28 is urged in opposing direct-ions by the control springs 33 and 34. An arm 35 of the control spring 33 engages a bent-up projection 35 of the control plate to urge the control plate in a counterclockwise direction. An arm 37 of the control spring 34 is entered in a small hole 33 in the control plate 28 to urge the control plate in a clockwise direction. For the control spring positions shown in FEGURE 2, the control spring 33 exerts a greater turning force on the control plate 23 than the lesser control spring 34 does and urges the control plate in a counterclockwise direction. With the arm 35 of the control spring 33 shifted to the position shown by the dotted lines in FIGURE 2, the lesser control spring 34 takes over and urges the control plate 28 in a clockwise direction.

The control spring 33 has a U-shaped section 39 which is contained in a hole 49 near the periphery of the workturning member 15. The U-shaped section 3% may be made with one or more loops and provides torsional spring action. An end 4-1 of the control spring 33 is secured in a small hole 42 in the work-turning member 15 to serve as a reference for the spring action.

The control spring 3 is contained in a hole 43 in the work-turning member 15. The hole $3 is of sufiicient size to allow unrestricted movement of the arm 37 which engages the control plate The other end 44 of the control spring 334 is secured in a small hole 45 in the workturning member 15 for maintaining the correct operative position of the control spring 34.

A shift pin 46 is mounted for vertical adjustment in the work-turning member 15 in a hole 47 which parallels and is located at the axis of rotation of the work-turning member. The shift pin d6 may be selectively moved to either of two operable positions at different elevations with respect to the work-turning member. The shift pin 46 has a conically expanded head which is received by a countersunk portion of the axial hole 4 7 when the shift pin is is in its extreme downward position. The diverging surface of the head of the shift pin 46 displaces the arm 35 of the control spring 33 when the shift pin is moved down. The arm 35 is preferably displaced far enough to break contact with the bent-up projection of the control plate 28 and permit the other control spring 3% to take over without restricting its range of action. The upward return movement of the shift pin is provided, at least in part, by the vertical component of force exerted on the head of the shift pin 46 by the arm 35 of the control spring 33. A spring 48 may be placed in the axial hole to ensure the upward movement of the shift pin 46.

Manual control of the direction of driving is given by a reverse control member which determines the vertical adjustment of the shift pin 46. In this embodiment, the reverse control member consists of a shift bar 49 which has two positions relative to the head Ill for indexing the direction of driving. The shift bar 49 has an inclined surface 56 adapted to engage the slightly rounded top of the shift pin 46 and to depress the shift pin when the shift bar is moved forward. The cover plate 19 has an elongated recess 51 to receive the shift bar 49 and permit limited forward movement. The wrench head ll is made with a channel 52 adjacent the cylindrical opening 13 to accommodate the shank of the shift bar 49. The back portion of the shift bar is provided with suitable gripping means to give easy manipulation for both forward and backward movement.

In operation, with the shift bar i) in retracted position as shown in FIGURES 3 and 5, the shift pin 46 would be in the position shown in FIGURE 5. The control spring 33 would then predominate over the control spring 34 to urge the control plate 28 counterclockwise. The pawl 23 would be driven by the control plate to the counterclockwise end of the concave recess 24 as shown in FIGURE 2. Turning the handle counterclockwise would wedge the pawl 23 between the teeth 14 in the head 11 and the walls of the concave recess 24 for driving the work in a counterclockwise direction. Turning the handle clockwise would release the pawl 23 from locking engagement and cause the pawl to engage successive series of teeth 14 in the head 11 until the handle was again turned counterclockwise for the driving stroke.

For driving in a clockwise direction, the shift bar 49 is moved forward to depress the shift pin 46. In its extreme forward position, the horizontal bottom surface of the shift bar extends past the center of the shift pin. The vertical pressure from the shift pin 46 on the horizontal bottom surface of the shift bar 49 maintains the shift bar in the forward position. With the shift pin in its lowest position, the control spring 33 would be disengaged from the control plate 28. The control spring 34 would then take over and urge the control plate in a clockwise direction. Thepawl 23 would be directed by the control plate 28 to the clock-wise end of the concave recess 24 for driving the work in a clockwise direction and for releasable ratcheting action in a counterclockwise direction.

FIGURES 6 and 7 show the invention in application to small rim or ledge 67 for positioning the control springs I 63 and 64-. The rim 67 may be undercut inside for holding a conventional pawl 53. The wrench head 54 should be larger than the wrench head of the previously described embodiment because the conventional pawl 53 engages the wrench head 54 with only a few teeth and increases the stress concentration on the wrench head. In addition, the internal teeth 55 in the wrench head 54 should not be broached through in order to leave a continuous bearing surface for the upper portion of the work-turning member 56.

The pawl 53 shown in FIGURES 6 and 7 is a one-piece pawl contained in a slot or chamber 60 formed on the side of the work-turning member 56. The pawl 53 has teeth 57 on opposite ends 58 and 59. The pawl teeth on the end 58 engage the teeth 55 for driving in a counterclockwise direction, and the pawl teeth on the end 59 engage the teeth 55 for driving in a clockwise direction. The ends of the pawl transmit thrust from the teeth 55 in two different directions or paths through the pawl to a shaft 61. The shaft 61 passes through the slot and has bearing support on both sides of the slot. The shaft 61 is pressed into a central hole in the pawl 53 or otherwise secured to the pawl so that the pawl and shaft rotate as a unit. The limited rotational motion of the pawl 53 within the slot 66 is sufiicient to bring either toothed end of the pawl into engagement with the teeth 55 in the head 54 while the other toothed end is free from engagement.

The top of the shaft 61 is formed with a crank 62 for turning the shaft and associated pawl in either direction. Control springs 63 and 64- engage the crank 62 for urging the pawl 53 in either a clockwise or counterclockwise direction. The control springs 63 and 64 are horizontally placed on top of the work-turning member 56 and have booked ends entered in small holes 65 and 66 in the workturning member. The work-turning member 56 has a the control springs 63 and 64 close to the top of the workt-urning member 56.

When the shift pin 46 is in its highest vertical position, the control spring 63, which provides the greatest force, will override the action of the control spring 64 and urge the pawl 53 to the position shown in FIGURE 6. The pawl 53 will be releasably held against the teeth 55 in the head 54 for driving the work in a counterclockwise direction. Depressing the shift pin 46 with shift bar 4-9 will force the control spring 63 from engagement with the crank 62 and permit the lesser control spring 64 to take over and swing the crank in a clockwise direction to bring the other end 59 of the pawl 53 into engagement with the teeth in the head 54, for driving in a clockwise direction.

While the invention has been shown and described in preferred forms, modifications may be made in various features of the invention by those skilled in the art. The dual control spring arrangement shown here may be applied to a reversible pawl of the type shownin FIGURE 2 but carried by the wrench head instead of the work-turning member. Changes may be made in the spring connections for the combination of one-piece reversible pawls and vertically adjustable control elements while retaining the advantages of resilient coupling for this particular application. Other changes may be made without departing from the invention as defined in the following claims.

What is claimed is:

1. In a ratchet mechanism, the combination of a driving member having a head, a work-turning member mounted for rotation in said head, reversible pawl means carried by said work-turning member for driving engagement with the head, and control means for directing the pawl means in reversible engagement with the head, said control means including two yieldable members mounted on said work-turning member and acting on the pawl means with unequal force, one of said yieldable members urging the pawl means in a direction to drive one way and the other yieldable member urging the pawl means in a direction to drive the opposite way, said control means including displacement means for moving the greater of the two yieldable members in such a direction as to relieve its pressure on the pawl means and permit the lesser of the two yieldable members to determine the direction of ratchet driving, the greater of the yieldable members predominating to determine the direction of ratchet driving in an undisplaced state.

2. A ratchet mechanism according to claim I, wherein said displacement means comprises an adjustable member carried by said work-turning member and having two operable positions in a direction paralleling the axis of rotation of said work-turning member, said adjustable member being so formed as to displace the greater of the yieldable members in one operable position.

3. Ina ratchet mechanism, the combination of a memher having a head, a work-turning member rotatably mounted in said head, one of said members having a circular toothed surface, a pawl carried by the other of said members in position to engage the circular toothed surface, said pawl having an arcuate side provided with teeth, said pawl being adapted for reversible engagement with the circular toothed surface with all of the pawl teeth being used for driving in both directions, and control means for bringing the pawl into reversible engagement with said circular toothed surface, said control means including two yieldable members acting on the pawl in opposing directions and of unequal magnitude, one of said yieldable members urging the pawl into position to drive in one direction and the other of said yieldable members urging the pawl into position to drive in the opposite direction, the greater of said yieldable members predominating to-direct the pawl for engagement with said circular toothed surface for one direction of driving, said control means further including means for relieving the force acting on .the pawl from the greater of the yieldable members, whereby the lesser of the yieldable members may direct the pawl for engagement with said circular toothed surface for driving in the opposite direction.

4. In a ratchet mechanism, the combination of a member having a head and another member rotatably mounted in said head, one of said members having a circular toothed surface and the other of said members having a recess open to said circular toothed surface, a pawl carried in said recess, said pawl being of smaller size than the recess to permit circumferential displacement of the pawl and withdrawal from the circular toothed surface, said recess having two ends adapted to engage the pawl for receiving the thrust of the pawl, the ends of said recess converging toward each other in a direction away from the circular toothed surface, one end of the recess receiving the thrust of the pawl for one direction of driving and the other end of the recess receiving the thrust of the pawl for the other direction of driving, said pawl having an arcuate side having teeth adapted to concurrent driving engagement with said circular toothed surface, all of said pawl teeth being used for driving in both directions, and control means for bringing the pawl into reversible engagement with the circular toothed surface, said control means including resilientlyacting means for selectively directing the pawl toward either one of said ends of the recess, said resiliently-acting means comprising two spring means acting on the pawl in opposite directions, one of said spring means urging the pawl toward one end of said recess while the other of said spring means urges the pawl toward the ther end of said recess, said control means further including manually operable means for displacing at least one of said spring means in such a direction as to change the force acting on the pawl from said last-named spring means so that one of the spring means may predominate to urge the pawl toward a selected one or" said ends of the recess.

5. In a ratchet mechanism, the combination of a member having a head and another member rotatably mounted in said head, one of said members having a circular toothed surface and the other of said members having a recess open to said circular toothed surface, a pawl carried in said recess, said pawl being of smaller size than the recess to permit circumferential displacement of the pawl and withdrawal from the circular toothed surface, said recess having two ends adapted to engage the pawl for receiving the thrust of the pawl, the ends f said recess converging toward each other in a direction away from the circular toothed surface, one end of the recess receiving the thrust of the pawl for one direction of driving and the other end of the recess receiving the thrust of the pawl for the other direction of driving, said pawl having an arcuate side having teeth adapted to concurrent driving engagement with said circular toothed surface, all of said pawl teeth being used for driving in both directions, and control means for bringing the pawl into reversible engagement with the circular toothed surface, said control means including adjustable means carried by one of said members and arranged for movement to different elevations in a direction paralleling the axis of rotation of the member mounted in the head, said control means including means for directing the pawl toward either selected end of said recess, said adjustable means being arranged to act on the last-named means so that the lastnamed means directs the pawl toward one end of the recess when the adjustable means is at one elevation and directs the pawl toward the other end of the recess when the adjustable means is at another elevation.

6. In a ratchet mechanism, the combination of a driving member having a head, a work-turning member mounted in said head for rotation therein, reversible pawl means carried by said work-turning member for driving engagement with said head, and control means engaging the pawl means for directing the pawl means in reversible engagement with the head, said control means including an adjustable member carried by one of said work-turning and driving members and having two operable positions in a direction substantially paralleling the axis of rotation of said work-turning member, said control means including resiliently-acting means adapted to bias'the pawl means to drive in a selected direction and operatively connecting said adjustable member to said pawl means, said adjustable member being arranged to displace said resiliently-acting means so that the resiliently-acting means biases the pawl means to drive in one direction when the adjustable member is in one operable position and biases the pawl means to drive in the other direction when the adjustable member is in the other of said operable positions.

7. A ratchet mechanism according to claim 6, wherein the control means further includes a manually shiftable member carried by said driving member and having two positions relative to said driving member whereby the direction of ratchet motion may be indexed, said manually shiftable member being arranged to act on said adjustable member so that said adjustable member is directed to one of its operable positions when the manually shit'table member is in one of its positions and directed to the other of its operable positions when the manually shiftable member is in the other of its positions.

8. In a ratchet mechanism, the combination of a member having a head with inwardly extending teeth, a work-turning member rotatably mounted in said head, a reversible pawl carried by said work-turning member in position to engage the teeth in said head, said pawl having a plurality of teeth for engagement with the teeth in said head, said pawl being adapted to transmit thrust in two directions through the pawl to the workturning member, and control means for bringing the pawl into reversible engagement with the teeth in said head, said control means including an adjustable member mounted for movement to either of two operable positions with respect to said work-turning member in the direction of the axis of rotation of the work-turning member, said control means including means resiliently engaging the pawl for urging the pawl to drive in a selected direction, the last-named means operatively con necting the adjustable member and the pawl, said adjustable member being arranged to move the last-named means according to the operable position of the adjustable member so that the last-named means has a reversible action on the pawl.

9. In a ratchet mechanism, the combination of a memher having a head with inwardly extending teeth, a workturning member rotatably mounted in said head, a pawl carried by said work-turning member in position to engage the teeth of said head, said pawl having teeth for engaging the teeth of said head, the pawl being adapted for driving in both directions, and control means engaging the pawl for directing the ratcheting action of the pawl, said control means including two resiliently-acting members acting between the pawl and said workturning member, one of said resiliently-acting members urging the pawl to drive in one direction and the other resiliently-acting member urging the pawl to drive in the other direction, the forces exerted on the pawl from the resiliently-acting members being of difi'erent magnitude, the resiliently-acting member of greater magnitude predominating to control the direction of driving, said control means including means for selectively displacing the resiliently-acting member of greater magnitude to reduce its force on the pawl, whereby the resilientlyacting member of lesser magnitude may control the direction of driving.

10. In a ratchet mechanism, the combination of a driving member having a head with inwardly extending 7' teeth, a work-turning member rotatably mounted in sm'd head, a reversible one-piece pawl carried by said workturning member in position to engage the teeth in said head, said pawl having a plurality of teeth for engaging the teeth in the head, said pawl being adapted to transmit thrust in two directions, relative to the pawl, to the work-turning member, and control means for bringing the pawl into reversible engagement with the teeth in said head, said control means including an adjustable member carried by one of said driving and work-turning members and arranged to have two operable positions at difierent elevations in a direction paraileling the axis of rotation of said work-turning memher, said control means including means responsive to the operable position of said adjustable member for selec-tively biasing the pawl to drive in either direction.

11. A ratchet mechanism according to claim 10, wherein the last-named means comprises two spring 5 members acting on the pawl, one spring member urging the pawl to drive in one direction and the other spring member urging the pawl to drive in the other direction.

References Cited in the tile of this patent

Claims (1)

1. IN A RATCHET MECHANISM, THE COMBINATION OF A DRIVING MEMBER HAVING A HEAD, A WORK-TURNING MEMBER MOUNTED FOR ROTATION IN SAID HEAD, REVERSIBLE PAWL MEANS CARRIED BY SAID WORK-TURNING MEMBER FOR DRIVING ENGAGEMENT WITH THE HEAD, AND CONTROL MEANS FOR DIRECTING THE PAWL MEANS IN REVERSIBLE ENGAGEMENT WITH THE HEAD, SAID CONTROL MEANS INCLUDING TWO YIELDABLE MEMBERS MOUNTED ON SAID WORK-TURNING MEMBER AND ACTING ON THE PAWL MEANS WITH UNEQUAL FORCE, ONE OF SAID YIELDABLE MEMBERS URGING THE PAWL MEANS IN A DIRECTION TO DRIVE ONE

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