US2963929A - Ratchet wrench - Google Patents

Description

W. A. BARNES RATCHET WRENCH Dec. 13, 1960 Filed Jan 28 INVENTOR v @m v Q WILLIAM A. BARNES BY WW MW w W XWWF ATTORNEYS zkai ia z United States Patent RATCHET WRENCH William A. Barnes, Utica, N.Y., assignor to Kelsey-Hayes Corporation Filed Jan. 28, 1959, Ser. No. 789,645

'2 Claims. (C]. 8162) This invention relates to ratchet wrench construction in general, and relates -more specifically to an improved pawl actuation means to control rotational direction.

Ratchet wrenches, whether of open end construction or with a socket attachment stud, are generally quite Well known and understood. Improvements have long been confined to refinements'of-operation.

Such ratchet devices employ an external manualcontrol handle, which'handle is used to throw a pawl or pawl means, from one operative position to another. Sometimes one position is a neutral position wherein 'no holding action is effected.

Generally, however, the handlemoves between two positions representing a clockwise drive, and a counterclockwise drive condition.

Further, the prior known constructions commercially available have such control handles located in an exposed position on the wrench 'surface, and in such position this is a hindrance to .placement of the wrench in close quarters. Worse 'still, in such exposed position, contact of the handle by any object can change the intended rotation direction and necessitate resetting of the ratchet direction.

Another principal object of this invention is to provide a manual control for such wrench which is recessed and protected against unintentional control actuation.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a top plan view of a wrenchconstructed according to the principles of this invention;

Figure 2 is a side elevational view of the wrench of Figure 1;

Figure 3 is an enlargement of the head area of the wrench shown in Figure 1 with a cover portion broken away; and,

Figure 4 is a cross-sectional view taken along line 44 of Figure 3.

Referring now to the drawing, the preferred commercial embodiment of the invention is illustrated in suflicient detail that one skilled in this art can appreciate the operative construction and the technique of proper use of the invention.

The reference character refers to the head portion of a wrench body, and the reference character 11 refers to the handle portion. This construction of handle and head portion is substanttially conventional in ap pearance.

The head portion 10 is bored out to provide a bore housing 12 passing laterally through the head 10. In this bore housing 12 resides a drive head 13. Drive head 13 is composed generally of a ratchet gear portion 14 having peripheral teeth therearound, and a rigid drive shaft 15 for the reception of suitable driven members such as socket devices.

Basically, it is the purpose of this wrench, as in con- 2,963,929 Patented Dec. 13, 1960 ventional wrenches, to interconnect the drive head '13 with the wrench proper by means of a pawl detent in order that the handle may ratchet freely in one direction and then apply drive force when the direction of the handle is reversed. However, in this invention, the pawl construction and ratchet operation are unique :and improved with respect to prior devices.

As best seen in Figure 3, a pawl detent 29 is located at one side of'the bore housing 12. The pawl dete11t20 is ofyoke form and has a first toothed end 21 and a-sec- 0nd toothed end 22. Pawl 20 has a fulcrum bearing surface 23, which is seated in asocket recess 27. Thus, the pawl ispivotable on'the fulcrum .23 about the recess 27 asa center, in order to engage, selectively, either the first end.21 or the second end 22 with the toothed periphcry of the gear ratchet portion 14 of drive head 13.

The ratchet gear portion 14 of 'the drive head 13 is counterbored to, provide the recess indicated by reference character 16. A control knob 30 resides in this recess. For the illustrated embodiment of the invention, .a control bar 31 is provided in order to permit .finger grip manual operation of the control knob 30. 1

A resilient C-shaped actuator 35 encompasses the control knob 30. A tab recess notch 26 is provided in knob 30. The actuator 35 is interlocked with knob 30 by means of a tab projection 38 which interfits into the'tab recess notch 26 in the knob 30. Thus, whenever the knob 30 is rotated about its axis, the C-shaped actuator '35 is rotated with the knob.

The actuator 35 has a first cam end 36 and a second cam end 37. In Figure 3 it will be seen that the pawl detent 20 has .two shoulder earns 24 and 25. Shoulder 24 is on the firstend 21 and .is actuated by contact of the actuator end 36 therewith. Likewise, the shoulder 25 on the pawl second-end 22 is contacted by the actuator end 37.

In Figure 3 the finger grip bar 31 has been rotated to move the knob 30 and the actuator 35 in a clockwise direction and thus the actuator end 37 has been caused to sweep along the shoulder 25 and lock the pawl detent against the right-hand side of the bore housing '12. Thus, the first end 21 of the pawl detent is brought into engagement with the peripheral teeth of the drive head 13. In such condition, as illustrated in Figure 3, if a pull is applied upon the handle 11 in an effort to rotate the head 10 in a clockwise direction about the axis of the shaft 15, adriveforce will be imposed through 'the shaft 15. The reason that relative movement of the head 10 and the drive head 13 is prevented is the fact that the pawl 20 is interlocked with the gear ratchet portion 14. Those skilled in the art of ratchet wrench construction will be readily able to visualize this locked condition. The C formation, and resilient nature of the actuator serves to hold the pawl yoke firmly in position, but allows reverse stroke ratcheting to take place. Upon reverse stroke of the drive handle, the engaged teeth of gear and detent are cammed apart. The actuator allows the yoke detent to pivot against the holding urge of the actuator to accomplish such ratcheting.

The finger grip bar 31 may be said to have a neutral position lying along the longitudinal axis of the handle, although in reality the bar is never maintained in such a neutral position. Hence, the neutral position is referred to only for the purposes of comparative reference. In Figure 3, as previously described, the finger grip bar 31 has been rotated in a clockwise direction with respect to the neutral position. Such rotation has caused the C-shaped actuator 35 and the related cam surfaces of the pawl detent '20 to move to a drive condition wherein drive through the shaft 15 can be accomplished in a clockwise direction. This accomplishment is unique in ratchet wrench construction. In conventionva1 construction, whatever control lever is provided for ft'ion. provides the proper type of control, and this. control is considerably desired by mechanics using thistool. There is no reverse thinking necessary in order to determine which way to throw the control handle to provide 1 the proper hand of operation.

It follows, that reversal of the position of the finger grip bar 31 to a position counterclockwise of the neutral position of that shown in Figure 3 will actuate the yoke detent 20 into a reversed position and create a counterclockwise driving direction of the tool.

To complete the assembly, a cover plate 32 is held over the top of the bore housing 12 by means of a holding screw 33. This cover plate will hold the C-shaped actuator 35 and the control knob 30 in the counterbore 16 and yet allow relative actuating movement of the control knob 30. In order to prevent excessive loosenessof the control 'knob, a pressure spring 34 is positioned at the bottom of the recess 16 as illustrated best in Figure 4.

It should be noted that the control knob 30 resides completely within the plane of the surface of head 10 and this is recessed to prevent accidental contact by an associated work member which causes an unwanted change of wrench direction of operation, and also permits a far more streamlined form for the wrench which vwill allow access in tight places.

Although this invention has been descibcd in its'preferred form with a certain degree of particularlity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is: a

1. A ratchet wrench comprising, a handle having an enlarged drive end, said drive end having a bore and a coaxial counterbore, a drive body rotatably carried by the handle and having a tool drive portion projecting .axially through the bore, the body also having a geared actuation portion disposed in the counterbore, means to 'hold the body against axial movement relative to the handle, said geared actuation portion including a periph eral gear and a bottomed bore extending generally axially from the end opposite said drive portion, a selector knob having a guide portion pivotally carried in said 4 bottomed bore, the handle also having a recess formed therein and in communication with the counter bore, a yoke pivotally carried in the recess, the yoke having first and second gear segments formed at its ends, a split ring spring operatively engageable with said yoke and in operative engagement with said selector knob, said knob having first and second adjustment positions, said first gear segment being held by the spring in yieldable engagement with the geared actuation portion when the knob is in the first adjustment position, said second gear segment being held by the spring in yieldable engagement with the geared actuation portion when the knob is in the second adjustment position, and means to retain the wrench in an assembled condition. 7

2. A ratchet construction and control, comprising, a body housing member, said housing member having walls defining an internal housing recess, a drive member, said drive member having a geared portion housed in said recess, said body housing member and said gear portion being relatively rotatable about a common axis, a

pawl yoke carried by said body laterally of said geared portion, said yoke having a pivotal axis generally par-allel said common axis, said yoke having a first and second gear engaging detent end, said yoke having a first posii tion wherein said first end is in detent engagementw-ith said geared portion and a second position wherein said second end is in engagement with said geared portion, a O-shaped control actuator spring having a first and second cam end, said actuator being positioned and guided for revolving movement around the said common axis, said first cam end in cam actuation contact with said yoke first detent end, said second cam end in cam actuation contact with said yoke second detent end, and said yoke being yieldable in the plane thereof to allow yoke pivotal movement to take place against the holding force of the actuator for reverse ratcheting of said geared portion past the holding detent.

References Cited in the file of this patent UNITED STATES PATENTS

Images