US2891434A - Ratchet wrench - Google Patents

Description

June 23, 1959 c, LQZENSKY 2,891,434

I RATCHET WRENCH Filed April 21, 1958 4 INVENTOR.

CHARLES fl [aznvsxr ATTORNEY w'rench having a driven I when driving a nut along 2,891,434 RATCI'IET WRENCH Charles Andrew Lozensky, Brooklyn, N.Y. Application April 21, 1958, Serial No. 729,890 Claims. (Cl; 81-60) The present invention relates to ratchet wrenches. More particularly it relates to ratchet wrenches adapted to "drive an object offering low resistance to back-motion, and even more particularly it relates to a hand driven ratchet wrench adapted for use in confined quarters.

It is an object of this invention to provide an improved ratchet wrench of the character indicated. I

It is a further object of this invention to provide a ratchet wrench which ratchets when operating on an object such as a threaded nut or bolt which is so free to advance or withdraw along its thread that it provides insutlicient resistance against back motion to cause a conventional ratchet wrench to ratchet.

It is also an object of the present invention to provide a ratchet wrench which is capable of ratcheting and which will not reciprocate idly even when driving an object having no resistance against back motion.

Another object of this invention is the provision of a midget ratchet wrench which is suitablefor use in closely confined quarters.

Yet another object of the invention is a ratchet wrench which is suitable for use by the fingers of one hand in confined quarters to drive helically threaded objects throughout a course of travel in at least part'of which there is little or no resistance to back motion of the object being driven.

A further object of the invention is to provide such a element located eccentrically in a circular driving handle, thereby providing a continuous finger-gripping surface and a minimum projection of the handle in one direction beyond the axis of the driven element.

A conventional ratchet wrench contains a pawl, click, detent, or similar locking member which in conjunction with a ratchet wheel or similar stepping mechanism provides positive drive in one direction and an escaping action in another. A spring or other biasing means urges the locking member against the ratchet wheel so as to secure positive ratcheting action. In order to overcome the effect of this biasing action 'and cause ratohetin'g'to occur'during the back or return stroke of the wrench, a force or torque sufficient to overcome of the spring must be applied to the driven member of the wrench, or the driven member will follow the reciprocating action of the handle of the wrench. Thus, a conventional ratchet wrench normally will not ratchet a threaded shaft until the nut has approached the limit of the unobstructed free thread and is subjected to sufiicient frictional resistance to back motion 'to overcome the bias of the spring in the ratchet mechanism.

While in some instances this problem maybe overcome by running a nut or screw'al'ong its thread by hand,

the residual bias until the limit of free travel is reached, or by using one hand to drive a ratchet wrench and another to hold the screw or nut (or the driven member of the wrench) so as to prevent back motion and cause ratcheting to occur, such methods are unsatisfactory in closely confined quarterswhere there may bebarely room' for one'hand or a few fingers and where the nut or screw may have to be driven in a recessed opening.

The ratchet wrench of the present invention readily 2,891,434- Patented June 23, 1959 overcomes these problems. In accordance with the present invention, a ratchet wrench adapted to drive an object offering low resistance to back motion and idle reciprocation comprises a handle, a driving member, ratchet means coupling said handle and said driving member, said ratchet means being biasedagainst ratcheting, and frictional braking means coupled to said driving member and adapted to overcome said bias so as to restrain said driving member from free motion, thereby causing ratcheting to occur and preventing idle reciprocation of said driving-member when driving an object lacking sufiicient resistance to back motion to overcome said bias. The present wrench maybe employed to drive a wide variety of sockets, tangs, ezg. screw drivers, bits and the like. The screw drivers, bits and the like may telescope within a socket and have stops thereon so that their length is adjustable as desired.

Other objects and advantages of the present inventionwill become apparent to those skilled in the art from a reading of the present specification in conjunction with the accompanying drawings, which constitute a presently preferred embodiment of the invention.

In the drawings:

Fig. 1 is a side elevation of a ratchet wrench constructed in accordancewith the present invention and illustrated as applied to a socket;

Fig. 2 is a cross-sectional view taken in the plane of Fig. l in-the directionindicated;

Fig. 3ris abottcm view of the wrench of'Fig. l with the finger ring 34*of Fig. l omitted for convenience of illustration.

Fig. 4 is an enlarged sectional view taken in the plane 4-4 of Fig. 1; and

Fig. Sis an auxiliary'lever handle which may be used in conjunction with the wrench of Fig. l to increase the torque applied thereto.

Referring to the drawings, a drive shaft 2 is journaled in and extends through a cylindrical body or handle 4 near the outer periphery thereof. The handle is knurled or ridged on its outer face so as to facilitate finger gripping.

The drive shaft 2 carries a toothed ratchet wheel 6 which is recessed within the handle 4. The teeth of the ratchet Wheel engage a pawl'S having two pairs of teeth 10, a recessed segment 12, and a dual track 14 cut on its periphery. The pawl is mounted on a pin 16 which extends through and is free to swivel in the body of the handle 4. Mounted on the upper end of the pin is a head18 carrying an arm' 20. A spring 22 urges a ball 24 into one half of the track in the periphery of the pawl, thereby providing a detent action.

As is apparent, rotation of the arm 20 serves to swivel the pawl 8- so as to change the portion of'the track in which the ball 24 rides from one half thereof to the other, thereby reversing the direction in which the shaft 2 drives and ratchet.

The lower extremity of the shaft 2 is square in crosssection and is provided with a detent 25 so as to accept and hold conventional drive sockets. Thesesockcts may be of any shape such as square, hexagonal, round, etc.

The upper extremity of the shaft 2 terminates in a ball 26. The ball is received in a clamp assembly 30 having a hollow socket clamp 32 at one end thereof and a finger ring 34 at the other end. The ball and the socket clamp constitute a swiveling friction brake as an integral part of the wrench, tension on the clamp being adjusted by means of a screw 35;

In use, a socket 36, shown in dotted outline in Fig. l, is placed on the lower end of the drive shaft 2. The index finger of one hand is slipped through the finger ring3'4 which is then held stationary by the finger. Alternatively any type of finger or hand grip such as a palm ring can be used and reference to the finger ring includes such means. The knurled driving handle 4 is operated by the thumb and middle finger of the same hand.

During the drive stroke, i.e., clockwise rotation of the driving handle when the swivelling pawl is in the position illustrated in Fig. 4, the teeth of the ratchet wheel ride on the periphery of the pawl which is held in position by the influence of the spring-loaded ball 24 in the track 14. On the back or return stroke, i.e., counterclockwise rotation of the driving handle when the swivelling pawl is in the position illustrated in Fig. 4, it is necessary to overcome the resistance of the spring 22 in order to cause the pawl to swivel the short distance (i.e., a portion of the half of the track in which the ball 24 is inserted) necessary to cause ratcheting to occur. (If this resistance is not overcome, the drive shaft will follow the driving handle as it is oscillated, and thus will reciprocate idly without ratcheting.)

The resistance necessary to accomplish ratcheting is transmitted to the drive shaft through the frictional braking assembly, i.e., the ball and socket clamp, from the finger which is inserted in the finger ring 34 and held stationary.

Thus, the ball slips in the stationary socket 32 and unidirectional positive coupling between the driving handle 4 and the drive shaft 2 is realized on the drive stroke. On the return stroke of the handle, contradirectional ratcheting of the drive shaft is accomplished even in the absence of any resistance to back motion on the part of the nut or screw being driven by the socket aflixed to the wrench. This occurs because the frictional resistance to slippage of the ball 26 in the socket 32 of the stationary clamp assembly 30 is greater than and overcomes the bias of the spring 22, thus causing the pawl to compress the spring and swivel to permit ratcheting.

The finger ring and socket clamp assembly may be positioned perpendicular to the drive shaft 2 as illustrated, or may be set at any convenient or comfortable angle.

The driving handle 4 is provided with tapped recesses 38 (Figs. 2, 3 and 4) into which a threaded lever handle 40 (Fig. 5) may be inserted when space permits so as to avail of greater additional driving torque.

While there has been disclosed and illustrated that which is presently considered to be a preferredembodiment, it is apparent that variations may be made and equivalents substituted within the scope of this invention. Thus, although in the illustrated embodiment the drive shaft is eccentrically mounted within a cylindrical handle so as to realize greater torque in conjunction with diminished overhang and increase clearance on one side of the handle, it is clear that the drive shaft may be concentrically mounted within the handle, and that handles of noncylindrical shape may be employed. It will also be apparent to those skilled in the art that a wide variety of frictional braking means may be substituted for the ball and socket joint presently illustrated, and that the handle" referred to herein need not be a finger operated handle but may be any suitable drive means on which a force is exerted in any appropriate manner.

It will also be apparent that the integral braking principle of this invention may be applied to a wide variety of ratchets, however the present embodiment is considered especially desirable in view of the fact that it is readily operable by the fingers of only one hand and may be used in closely confined quarters. While the invention has been described with reference to one embodiment thereof as hereinbefore set forth, it is to be clearly understood that the invention is not limited thereto, but includes various modifications and equivalents within the scope of the appended claims.

What is claimed is:

1. A ratchet Wrench adapted to drive an object olfering low resistance to reverse movement comprising a handle, a driving member, ratchet means coupling said handle and said driving member, said ratchet means being biased against ratcheting, and frictional braking means coupled to said driving member and adapted to overcome said bias so as to restrain said driving member from free motion, thereby causing ratcheting to occur and preventing idle movement of said driving member when driving an object lacking suflicient resistance to reverse movement to overcome said bias.

2. A ratchet wrench adapted to drive an object offering low resistance to reverse movement comprising a handle, a drive shaft mounted movably in and extending through said handle, said shaft terminating at one end in means for attaching a socket member and at the other end in a circular member, ratchet means disposed within said handle and coupling said handle and said shaft, said ratchet means being biased against ratcheting, and a swivelling brake in frictional engagement with said circular member, the frictional resistance of said brake being greater than said bias, thereby causing ratcheting to occur and preventing idle movement when driving an object lacking suflicient resistance to reverse movement to overcome said bias.

3. A ratchet wrench adapted for use by the fingers of one hand in driving an object offering low resistance to reverse movement comprising a finger driven rotating cylindrical handle, a drive shaft mounted movably in an eccentric position within and extending through said handle, said shaft terminating at one end in a means for attaching a socket member and at the other end in a ball, a spring-biased ratchet disposed within said handle and coupling said handle and said shaft, said spring causing said ratchet to ofier resistance against ratcheting, and a finger-held clamp in frictional engagement with said ball whereby sufficient frictional resistance may be transmitted to said shaft to overcome said resistance and cause ratcheting of said wrench to occur when driving an object lacking resistance to reverse movement.

4. A ratchet wrench as set forth in claim 3 wherein said clamp is a socket clamp to which is atfixed a finger nng.

5. A ratchet wrench adapted to be held and operated in confined quarters by the thumb and fingers of one hand and suitable for driving an object lacking resistance to reverse movement comprising a cylindrical handle, a drive shaft mounted movably near the periphery of and extending through said handle, said shaft terminating at one end in means for attaching a socket member and at the other end in a ball, a spring-biased reversible ratchet journaled in said handle and coupling said handle and said drive shaft, said spring causing said ratchet to offer resistance against ratcheting, a socket clamp in frictional engagement with said ball, said clamp having compression-adjusting means for adjustment of the friction between said clamp and said ball, and a finger-fitting ring afiixed to said clamp, said cylindrical handle, ball-carrying drive shaft extension, and ring-carrying clamp being disposed for easy accommodation within the grasp of the thumb and fingers of a single hand, said cylindrical handle being adapted to be spanned and rotated by the thumb and a finger of one hand and said ring-carrying clamp being adapted to be held stationary by another finger on the same hand, whereby sufficient frictional resistance may be transmitted to said shaft from said finger-held clamp to overcome said resistance and cause ratcheting of said wrench to occur when driving an object lacking resistance to reverse movement. I

References Cited in the file of this patent UNITED STATES PATENTS 1,868,839 McNaught et al. July 26, 1932 2,542,241 Fors Feb. 20, 1951 2,735,324 Goldwater et al Feb. 21, 1956 2,778,396 Swain Ian. 22, 1957 2,803,980 Vogel Aug. 27, 1957

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