Implements having elongated members disposed for cooperative engagement about a joint are widely used by those desiring to transmit a force through the joint to a working piece engaged by the working surfaces of the implement. In particular, tools such as scissors generally comprise two elongated members disposed for cooperative engagement about a pivotable joint. To facilitate operation of the implement by the user, handles conforming to the fingers or hands of the user are preferably molded onto the force applying end (also called tang) of each elongated member, or in the case of anvil-type implements, one of the elongated members is entirely typically made of molded material.
As is well known, the joint in most of these implements commonly comprises a rivet or screw to maintain the members in suitable cooperative position, and washers when desired. Assembling such pivoted tools typically requires production personnel to bring apertures formed in the separately manufactured elongated members into registration to install the rivet or screw (and washers as necessary) to maintain those members in assembled relationship. In addition, to adjust the friction between the members to the desired amount, post-manufacturing finishing and adjusting operations are almost always required.
It has been found, however, that pivoted implements having screws or rivets tend to lose their original factory adjustment due to mechanical wear in the joint during normal operation. This deficiency has already been recognized and addressed by those skilled in the art and more particularly by those skilled in the scissors art. For example, U.S. Pat. No. 2,626,460 to Wahl discloses a pair of scissors in which the hinge is designed to enhance the durability of the frictional adjustment between the pivot members. Another approach to address mechanical wear has been disclosed in U.S. Pat. No. 3,735,763 to Shannon et al. In Shannon, one handle member is secured by a retaining clip to a hub formed integrally with the other handle. The clip, having an internal diameter smaller that the hub, causes frictional engagement between the hub and clip ensuring that the handles are maintained in assembled relationship.
From the foregoing, it can be readily recognized that prior art tools having elongated members maintained in cooperative position, such as scissors or the like, typically include a pivot member comprising several components which are susceptible to wear. In addition, the members to be joined are also typically provided with suitable apertures to permit their assembly. Necessarily, the manufacturing and assembling of such prior art tools usually includes several operations which, as a result, increase the cost of these items. These ultimately are all drawbacks, either for the manufacturer or the user.
Thus, it is desirable to provide tools such as scissors which are constructed to alleviate problems associated with prior art devices, i.e., in which the pivot member is modified or replaced, thereby eliminating problems associated with the mechanical wear in the pivot. The present invention responds to those needs while at the same time providing a new structure requiring fewer manufacturing and assembling operations.
USPTO Backgrounds
USPTO Backgrounds