Wireworking – Implements – Stretchers
Reexamination Certificate
2000-10-13
2002-04-30
Larson, Lowell A. (Department: 3725)
Wireworking
Implements
Stretchers
C007S131000
Reexamination Certificate
active
06378569
ABSTRACT:
TECHNICAL FIELD
The present invention relates generally to tools; and, more specifically, to a multipurpose hand tool useful in working with flexible duct, the hand tool comprising, in combination, a knife, a wire cutting tool, and a band-clamp tensioning means.
BACKGROUND ART
Tools are a necessary and essential asset of any tradesman. Having the proper and most efficient tool for a given task can result in an enormous cumulative reduction in man-hours and material, and, thus, costs. One particular trade in which the preferred embodiment of the present invention can be utilized is the installation and maintenance of heating and air-conditioning ventilation systems. Within this trade, flexible ductwork must be cut to fit a specific leg or piece of the ventilation system.
Well known in the art, this ductwork is comprised generally of an outer sheath of protective flexible, sheet-like material, usually silver in appearance. The outer sheath typically overlies a bat of conventional fiberglass-type insulation. The form of the ductwork is maintained through the use of a wound, continuous or semi-continuous plastic or metal wire, contained within a sheet-like barrier. The configuration of such flexible ductwork may vary by manufacturer and by type of ductwork. The advantage in the use of flexible ductwork is that it may be conveniently cut and shaped to a customized configuration.
During the installation of the flexible ductwork, the ductwork must be attached to a confronting, adjoining piece, such as, for example, a manifold, vent, or in-line adapter. Such pieces typically include a short, thin walled, cylindrically-shaped adapter over which the flexible ductwork may be positioned and attached during installation. It is typical to utilize for such purposes a type of flexible clamp known as a band-clamp. While several forms of band-type clamps are well-known in the art, a particular form has come into widespread use during recent years. This form of band-clamp is manufactured principally of a flexible, narrow, strap-like material, often of plastics or nylons. One end of the clamp comprises a tapered tip; the other, a clamp head. Closely spaced, tooth-like ridges are formed upon one of the flat sides of the band, along the area between the tip and the head. The head has a slot through which the tip of the band may be presented. Within the slot is a flat, tongue-like element, bent at its end, and further shaped for ratchet-like engagement with the tooth-like ridges of the band. This arrangement provides for unidirectional insertion and locking of the band at each tooth-like ridge, as the band is inserted and drawn through the head.
During the typical installation process, one end of the flexible ductwork is applied over the adapter of the confronting piece. A band-clamp is then positioned over both the flexible ductwork and the underlying adapter, whereupon the band-clamp is tightened according to preferred installation parameters. Finally, the excess portion of the band-clamp is cut-off so that it will not subsequently hang or otherwise interfere with the system.
Prior art installation methods, and the devices attendant to such purposes, however, have required that the installer have access to up to three separate tools in order to perform these tasks. That is, he must have one tool, such as a knife, for cutting the outer sheath and insulation portions of the flexible ductwork; a second tool, such as a wire cutter, for cutting the plastic or metal wire portion; and, a third tool, such as a cable tie tensioning tool, for tightening and cutting the band-clamp. Because the installer typically works in close confines such as attics and crawl spaces, the need to carry and utilize three separate tools to perform the installation of flexible ductwork is both cumbersome and inefficient.
In an attempt to overcome some of these deficiencies, certain integrated tools have been proposed. Examples of such devices may be found by reference to U.S. Pat. No. 5,185,930 to Hamlin; U.S. Pat. No. 5,226,237 to Rancour et al.; U.S. Pat. No. 5,303,475 to Baker; and, U.S. Pat. No. 5,625,951 to Hamlin. In light of the present invention, however, the aforementioned designs are cumbersome to use, relatively expensive to purchase, and heavy to carry.
It is, thus, readily apparent that a new and improved, multipurpose tool is needed that is relatively lightweight, easy to use, and inexpensive. It is, therefore, to the provision of such an improvement that the present invention is directed.
BRIEF SUMMARY OF THE INVENTION
Briefly described, in a preferred embodiment, the present invention overcomes the above-mentioned disadvantages by providing a multipurpose flexible duct hand tool comprising, in combination, a knife, a wire cutting means, and a band-clamp tensioning means, the tool being relatively compact, lightweight, easy to use, and inexpensive.
More specifically, the present invention, in the preferred embodiment, comprises a knife portion having a blade member, a cutting notch and a wire cutting member, a band-clamp head grasping means, and a handle member; a cutter portion having a wire cutting member, a band-clamp band grasping means, and a handle member; a pin for pivotally joining the knife and cutter portions; a spring for biasing the handle member of the cutter portion to the open position; and, a hook for locking the device in the closed position.
Preferably, the cutter portion is pivotally secured to the handle member of the knife portion via a screw, rivet, or pin member. One end of the spring is attached generally to the handle member of the knife portion, and the other end is attached generally to the handle member of the cutter portion; thus, urging the handles away from each other. In the preferred embodiment, the band-clamp head grasping means is positioned on the handle member of the knife portion in such a position to limit the travel of the cutting member of the cutter portion. Thus, in use, the cutter portion is in the open, ready-for-use position. For carrying and storage safety concerns, a lock mechanism comprising a hook-like member, carried preferably on the cutter handle, and a capturing means, carried or formed on the knife handle, is provided to lock the two handles together in the closed position.
The cutting member comprises wire cutting member having a cutting edge that generally travels in a curved path when the cutter handle is pivoted, and in close proximity to the cooperating notch and wire cutting member formed on the knife handle. As such, in use, the wire to be cut is extended through the notch and the user simply squeezes the handles together; thereby, pivoting the cutter edge to and through the wire and, thus, severing the wire.
Accordingly, for flexible ductwork cutting applications, the blade of the knife portion is utilized to cut the periphery of the outer sheath material and the fiberglass insulation. Upon contact with the wire, the wire is inserted through the notch and the cutter handle is squeezed toward the knife handle; thus, severing the wire. It should be noted that the preferred embodiment of the present invention may be utilized for numerous applications requiring the cutting of a variety of materials.
Provided on the cutter portion and on the knife portion are means for grasping and subsequently tensioning a band-clamp of a type utilized in the heating, ventilation, and air-conditioning field. Upon looping and presenting the band portion through the head portion of the band-clamp, the operator places the head of the band-clamp adjacent the knife portion grasping means, and the band portion through the cutter portion grasping means. Upon operation of the tool handle, the band-clamp is tightened in successive increments according to the tension desired by the operator. The cutter portion of the device of the present invention may then be utilized to shorten any excess band portion to an appropriate length.
In an alternate embodiment, the respective handles of the device are reconfigured into a plier-like shape and form in order to provide additional operato
Hughes & Kaplan
Kaplan, Esq. Barry E.
Larson Lowell A.
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