Tools – Wrench – screwdriver – or driver therefor – Rigid jaws
Reexamination Certificate
1999-11-09
2001-08-21
Morgan, Eileen P. (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Rigid jaws
C081S186000
Reexamination Certificate
active
06276240
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to hand tools, and more particularly to wrenches of the type known as open end. The novel wrench can drive many different sized fasteners by a single tool with ratcheting action, and can do so in two opposite directions. The present invention finds application in any field wherein hexagonal or similar headed fasteners are employed to assemble machines, furnishings, and objects of all types.
2. Description of the Prior Art
Hand wrenches for tightening and slackening threaded fasteners having polygonal heads are old and well known. These wrenches have made the use of such fasteners quite practical, since they readily enable necessary force to tighten and slacken fasteners. Varieties of wrenches include two headed open end wrenches typically formed from a single piece of steel. Open end wrenches have the advantage of lacking relatively movable parts. However, certain minor yet annoying deficiencies in the use of wrenches remain. One deficiency is that each head of most wrenches is configured to engage only one size fastener head. Since heads vary in size, usually in proportion to shank size, mechanics and craftsmen are usually obliged to have available an extensive plurality of wrenches to assure possessing a wrench suitable for each fastener head size frequently encountered.
A second problem frequently encountered in utilizing hand wrenches is their propensity to deform corners or apices formed at the juncture of two flat facets of the polygonal fastener head or nut. Frequently, deformation takes the form of rounding of the usually sharp line of intersection of two flat facets. In some cases, plastic deformation results in a distortion of a hexagonal or other polygonal configuration. In this case, an originally flat facet may bulge to the extent that the head of the fastener does not conform to a tool having a polygonal opening configured to receive the head of the fastener.
Box and ratchet wrenches apply a significant portion of force at the apices of the fastener head. Therefore, likelihood of rounding and deformation is significant. Simultaneously, if a fastener head has been deformed, a wrench may lose its ability to turn that fastener. The fastener may become useless, and if deformed in the installed, tightened condition, may prevent ready disassembly of the article to which it is fastened.
Another aspect in which hand wrenches are deficient is that because many fasteners require a large number of rotations of their threaded shanks to fully install and remove, an open end wrench is frequently removed from engagement with the fastener head and replaced thereon in an advantageous position to turn the fastener. The effort of frequently removing and replacing an open end wrench is laborious in that it noticeably increases the amount of time to install and remove fasteners compared to the use of ratchet action wrenches which do not need to be removed from engagement with the head.
The prior art has sought to improve hand wrenches in various ways. U.S. Pat. No. 2,671,368, issued to Fritz Diebold on Mar. 9, 1954, describes a wrench which can engage a plurality of fastener sizes, albeit only one at a time. This alleviates the necessity of possessing many wrenches. The wrench of Diebold also imposes force on flat facets of the fastener head between the apices thereof, thereby reducing likelihood of damage to fastener heads. However, the wrench of Diebold does not provide ratchet action, as can the present invention.
U.S. Pat. No. 1,479,772, issued to Walter Herbert Cook on Jan. 1, 1924, describes an open end wrench which provides ratcheting action, and can engage selectively any one of several nominal sizes with one wrench head. However, the wrench of Cook cannot apply torque to a polygonal fastener head only at the flat surfaces, while sparing the apices of the head from potentially deforming force.
U.S. Pat. No. 999,968, issued to Edwin A. Denham on Aug. 11, 1911, illustrates a wrench which accepts plural fastener sizes, which provides ratcheting action, and which applies torque to the flat facets of polygonal heads of fasteners. However, cooperation between the wrench head of Denham and a polygonal fastener is such that the fastener fits perfectly into the wrench, as illustrated in FIGS. 5, 6, and 7 in Denham. By contrast, adjacent flat surfaces of the novel wrench are arranged at an angle which prevents the facets of the wrench from abutting in flush contact with the wrench. A space or gap is created which accommodates potential deformation of the fastener in the present invention. This feature is absent in Denham.
U.S. Pat. Nos. 446,324 and 463,137, issued to Daniel H. Carpenter on Feb. 10, 1891, and Nov. 17, 1891, respectively, illustrate wrenches which receive plural fasteners, which ratchet, and which apply torque to facets of the fastener. However, unlike the present invention, there is no abutment of flat surfaces of both the wrench and of the fastener. Also, the wrenches of Carpenter do not provide the amount of accommodation of deformation of the fastener, as seen in the present invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The present invention sets forth an open end wrench which can engage plural fastener heads with one wrench head, which offers ratchet action, and which avoids rounding the apices of polygonal fastener heads. The novel wrench presents a generally conventional appearance upon first glance, having an elongate flat shank terminating at each end in an open head having two jaws. Configuration of the jaws, however, departs from prior art practice in that the features confer three characteristics none of which operates to the exclusion of the others.
One characteristic is that the interior surface of one jaw imposes torque to the fastener in a manner avoiding rounding or otherwise deforming the apices of the fastener head. One jaw of each head is stepped and the opposing jaw of the same head is specially curved to engage the fastener head in a manner assuring that torque is imposed mostly on a flat facet of the fastener head. Each step formed in the stepped jaw, taken with the interior surface of the opposing jaw, corresponds to one nominal fastener head size. Configuration of the steps and of the opposing jaw is such that torque is imparted to the flat facets of a polygonal fastener head, with little if any being imposed on the apices.
Furthermore, angles of the steps are such that only one flat facet of the head of the fastener is engaged in surface contact. This feature accommodates polygonal heads which have been deformed so that bulges are formed near the apices. The novel wrench is thus usable not only with new fasteners in perfect condition, but also with old fasteners which have suffered distortion as a result of abuse.
A second characteristic is that the steps are so configured that turning the wrench in one direction rotates the fastener, and turning the wrench in the opposite direction causes slippage between the wrench and the fastener head. This motion is, in effect, ratcheting action between the wrench and the fastener, although the wrench is slightly displaced relative to the rotational axis of the fastener when it slips. For purposes of tightening and slackening fasteners, this minor degree of displacement is not objectionable and indeed may possibly not even be noticed by the user.
A third characteristic is that each wrench head has sufficient steps formed therein that the wrench head accepts more than one nominal fastener size. In summary, any one novel wrench fits many nominal fastener sizes, ratchets relative to the driven fastener, and avoids deforming or rounding the fastener head.
Accordingly, it is one object of the invention to provide an open end wrench which fits a plurality of nominal fastener sizes.
It is another object of the invention that the novel wrench ratchet relative to a driven fastener, so that it need not be manua
Danganan Joni B.
Morgan Eileen P.
Siemens Patent Services LC
LandOfFree
Multi-sized, reversible ratcheting action open end wrench does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Multi-sized, reversible ratcheting action open end wrench, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multi-sized, reversible ratcheting action open end wrench will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2517738