Tools – Wrench – screwdriver – or driver therefor – Handle clutched to head
Reexamination Certificate
2000-09-12
2001-11-20
Smith, James G. (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Handle clutched to head
C087S060000
Reexamination Certificate
active
06318215
ABSTRACT:
FIELD OF THE INVENTION
The invention relates in general to hand tools and more particularly to open-end ratchet wrenches for manipulating nuts or bolt heads.
BACKGROUND OF THE INVENTION
Open-end ratchet wrenches and pliers have been designed in many different forms or configurations. They are necessary to provide the tightening or loosening of a threaded bolt or nut in tight or limited spaces. As examples, see U.S. Pat. Nos. 4,604,919; 5,249,487 and 5,924,341.
Problems encountered with open-end ratchet wrenches of the prior art are inadequate and un-uniform drive support of the socket portion of the wrench which directly engages the nut or bolt head to be manipulated, and/or inadequate or sloppy gripping action between the socket portion and the nut or bolt head to be manipulated. It is a principal object of the present invention to eliminate these disadvantages.
For example, in the structure illustrated in U.S. Pat. No. 5,924,341, cogwheel 20 is supported in cradle 28 by opposed pawls 17 and 40 which are spring biased to prevent rotation of cogwheel 20 in one direction. This arrangement provides un-uniform drive support for cogwheel 20 in cradle 28 as it is obvious when viewing the figures that when cogwheel 20 rotates counterclockwise relative to the cradle 28 there is nothing in the bottom of the cradle 28 to support the teeth 22 of cogwheel 20, which are free to engage the bottom U-shaped wall of cradle 28. The same problem arises with the structure shown in U.S. Pat. No. 4,604,919 wherein opposed spring biased pawls 24 prevent rotation in one direction of socket 40, but the bottom annular surface of socket 40 is permitted to slidably engage with friction against the surface 19 of the wrench head 16, providing undesirable friction drive engagement of the socket portion of the wrench.
Similarly, the present inventor's wrench as illustrated in U.S. Pat. No. 5,249,487 utilizes toothed faces 14 of gears to engage the outer faces and corners 20 of the nut 19 which provides a sloppy gripping action between the socket portion and the nut or bolt head to be manipulated.
SUMMARY OF THE INVENTION
The open-end handheld ratchet wrench of the present invention is comprised of a rigid semi-circular jaw cradle defining an interior semi-circular channel which is substantially U-shaped in cross section and oriented so that an open side of the channel faces the axis of the cradle whereby the channel has two spaced apart open-ends. An elongated handle is secured to this cradle and extends radially outward therefrom on a side opposite from the channel. At least two radial recesses are arranged in spaced relationship in a bottom portion of this cradle channel and they face the cradle axis. A gear is mounted in each of these recesses for rotation on a gear axis which is parallel to the cradle axis with a portion of each gear protruding into the channel. At least one ratchet pawl is mounted in the cradle and positioned to prevent rotation of at least one of these gears in one direction. A cogwheel having a toothed outer perimeter is provided and dimensioned for meshing with the gears. The cogwheel is further provided with a polygonal throughbore and a slot extending between the outer perimeter and the throughbore.
The polygonal throughbore is dimensioned to mate a particular nut or bolt head for manipulation and the slot is provided for access of a threaded shaft.
The cogwheel is dimensioned to be freely slidable into the open ends of the channel for resting against and meshing the toothed outer perimeter thereof with the gears.
A rachet pawl may be mounted in the cradle for each one of the gears and positioned to prevent rotation of all of the gears in the one direction. In this regard also, at least two gears are required and four or more such radial recesses with corresponding gears may be provided in spaced relationship in the bottom of the cradle channel.
Generally at least two and normally a number of the cogwheels will be provided which have substantially identical outer diameters for use with the tool, but have respective polygonal throughbores of different sizes for mating and manipulating corresponding nuts and bolt heads of different sizes.
REFERENCES:
patent: 4604919 (1986-08-01), Rollo
patent: 5249487 (1993-10-01), Armfield, IV
patent: 5924341 (1999-07-01), Brooks
Carothers & Carothers
Smith James G.
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