The present disclosure is directed to a ratchet wrench mechanism, and one which is different in operation in that it does not include a ratchet mechanism which advances by a finite measure. This structure incorporates a toothless drive which thereby enables rotation by an infinitely varied amount.
In the use of hand tools, there is a well appreciated need for ratchet type mechanisms. Indeed, ratchets in conjunction with socket drives are used by practically all machinist and repair personnel. As a generalization such devices are extremely handy for service work. There is however a limitation at times arising from the physical locale at which the socket connection is somewhat constrained. Sometimes, rather than use a socket connected with a ratchet, the only choice which is permitted by the circumstances of use is to engage a nut or bolt with an open end wrench. Nonadjustable box and open end wrenches are normally available for this purpose. Especially with an open end wrench, a nut can be engaged from the side without having to slip the wrench over the head. This type of motion permits one to engage the bolt head or nut on the bolt laterally. Sometimes, that is the only access which is permitted.
One of the difficulties with use of a ratchet wrench is the fixed incremental movement. The fixed increment of travel is determined by the spacing of the teeth involved in the ratchet mechanism. These teeth are normally arranged in a regular spacing. Since the device moves a catch mechanism from the first tooth to the next tooth, each advance of the ratchet requires a finite advance. In other words, the ratchet mechanism must drive the socket through a fixed angle of rotation, or some multiple thereof. If it is convenient, the handle can be moved so far that several incremental steps are achieved during the ratchet advance. If it is not handy or if the external working space is constrained, then difficulties arise in this regard. As will be understood, if the arcuate motion of the user is constrained by half, then tightening requires twice as many ratcheting movements to achieve the same amount of wrench transferred rotation.
The foregoing is especially true in a system which utilizes a wrench which has a fixed step or lead in the ratchet mechanism. Briefly, that describes those devices which are in popular fashion nowadays. Such a device is exemplified by the disclosure in U.S. Pat. No. 3,204,496. Briefly, this patent is directed to a ratchet mechanism which uses a spring loaded FIG. 8 shaped tooth caught in a raceway on the exterior of a socket and on the interior of a housing. In U.S. Pat. No. 3,398,612 a ratchet mechanism is shown which has spheres captured in a raceway, the raceway having one wall which is a cylinder and another wall which has an undulating surface which creates a wedge shaped cavity. It is a sphere related ratchet mechanism.
Another structure is shown in U.S. Pat. No. 4,491,043 illustrating a number of different embodiments which utilize a sphere which moves into a locking or unlocking position in conjunction with a tapered cavity. Last of all U.S. Pat. No. 3,590,667 sets forth a roller as opposed to a sphere, and the roller is captured in a tapered chamber.
The device of the present disclosure can be readily distinguished from the structures described above in the four specific references noted. The present apparatus utilizes a socket of conventional six sided construction but one which omits one side so that it functions as an open end wrench or socket. The structure further utilizes a surrounding, external, centered rib, halfway between the top and bottom, which rib provides a working surface on the top and bottom. The rib is incorporated to support, in frictional sliding engagement, two opposing wedges. One wedge is located above the rib and another is located below the rib. The wedges are enclosed in internal cavities each of which has a tapered surface positioned to drive the wedge frictionally into contact with the surrounding rib around the socket. This movement by the two opposing wedges provides a clamping action, thereby preventing further movement. On clamping, the wedges prevent further rib and socket rotation and assist in locking the socket against rotation. The wedges are long enough to span the gap in the rib at the open side of the socket. In summary, the locking action occurs when the ratchet mechanism is rotated in the direction resulting in wedge latching, and that can occur after any amount of angular rotation in the opposite direction. That might occur anytime when the user operates the device in the opposite direction to achieve latching. The incremental movement is not a fixed angle of rotation as occurs with a tooth equipped ratchet mechanism.