Tools – Tool jaw – Jaw features
Reexamination Certificate
1998-08-20
2001-04-17
Scherbel, David A. (Department: 3723)
Tools
Tool jaw
Jaw features
C081S418000, C029S268000, C072S379200
Reexamination Certificate
active
06216568
ABSTRACT:
BACKGROUND OF THF INVENTION
The present invention relates generally to a novel set of pliers and to a method for using said pliers to remove knockouts from steel outlet boxes, electrical conduit boxes or junction boxes and the like.
In the construction industry, it is widely known to use steel outlet boxes or junction boxes to serve as the point of origin, termination or coupling for electrical wiring, conduit and the like. The junction boxes are usually comprised of four side walls and a back wall. Since the direction of entry to the junction boxes varies, the side walls contain a plurality of removable knockouts. Further, to customize the placement of such metal boxes while also maintaining their integrity, the knockouts are only removed from the sides of the junction boxes which will receive wiring, conduit or the like. Normally the knockouts are coined or cut into the metal side walls of the respective junction box except for a tab, where the tab primarily secures the knockouts to the junction box.
The normal practice in the industry for removing knockouts is to place the head of a screwdriver within the circumference of a knockout and to strike the screwdriver with a blunt object, such as a hammer. This normally produces a force in one direction that fractures a portion of the knockout thereby causing the knockout to bend in relation to the supporting side wall of the junction box. The head of the screwdriver can then be used to further pry or bend the knockout in relation to the supporting side wall. With one side of the knockout now accessible, a pair of pliers or other gripping means can be used to secure the knockout and bend and twist the knockout until the remaining portion of the knockout is fractured thereby releasing the knockout. This process is time consuming and has a potential for damaging the junction box.
Also, it is sometimes the case that modification of junction boxes that are already installed will be performed. Under the normal practice in the industry, this may be problematic because fracturing the concentric knockout with a hammer and screwdriver requires adequate clearance and installed junction boxes may be located in tightly fitted areas.
The pliers that are currently available do not provide an adjustable plier jaw structure capable of quickly and easily removing knockouts. For example, as it is known in the art, pliers typically include two plier arms which are pivotally and adjustably interconnected, where the two plier arms further include opposing jaw portions that abut one another. As is further understood by those skilled in the art, the abutting portions of the pliers jaw allows the pliers to grip objects of varying sizes. This is typically performed by pivoting the plier arms in a manner to cause the two opposed jaw portions to form an open jaw, placing a particular object within the jaws, and then pivoting the plier arms in an opposite manner to cause the two opposed jaw portions to close on the object. The plier arms can also be adjusted to provide a larger or smaller jaw opening. An example of means for adjusting the size of the jaw opening are more clearly disclosed in U.S. Pat. No. 5,134,908. This patent discloses several different embodiments for pivotally and adjustably interconnecting two plier arms. Specifically, the jaws can be selectively adjusted to a variety of preset positions. Further examples of adjustable pliers may also be seen in U.S. Pat. No. 4,890,519, U.S. Pat. No. 4,901,609 and U.S. Pat. No. 5,676,029.
While the adjustable pliers shown in the prior art work well for their intended purpose and for removing knockouts once they have been fractured, they are not capable of quickly and easily fracturing the knockouts. In fact, this is why pliers are not currently used in the process of fracturing knockouts. This results from the fact that pliers are designed to provide force at a single point, and in primarily, equal and opposite directions. Thus, such pliers are not capable of providing the torque necessary to shear or fracture the knockout.
As a result of these noted deficiencies in the prior art, it is an object of the present invention to provide a set of pliers having an improved means for quickly and easily removing knockouts and improved means for providing opposing and offset forces which produce a greater quantity of sheer force upon a concentric or standard knockout.
SUMMARY OF THE INVENTION
The subject invention overcomes the deficiencies in the prior art by providing a set of pliers capable of providing two opposing and offset forces upon concentric and disc knockouts with a single tool and a method for removing said knockouts from steel outlet boxes, electrical conduit boxes or junction boxes and the like. This includes the various elements of the invention which act in conjunction with one another to quickly and easily remove knockouts. For example, the pliers include a first arm having a first end and a second end and a second arm having a first end and a second end, where the first arm and the second arm are pivotally connected with respect to each other by an interconnecting mechanism located between the first and second ends thereof. The first arm forms a first jaw located above the interconnecting mechanism of the first arm and the second arm forms an opposing, second jaw located above the interconnecting mechanism of the second arm. The first jaw includes a first projection that extends from an area between the end of the first jaw portion and the interconnecting mechanism. The second jaw of the second arm includes a second projection that extends from the end of the second jaw. The end of the first projection abuts the second jaw and the end of the second projection abuts the first jaw. Thus, the first and second projection are offset from one another so that they do not touch. By strategically placing one of the projections within the circumference of a knockout located on a junction box and the other projection along the outer periphery of said knockout and squeezing the first and second arms, opposing and offset forces are applied to the knockout and junction box frame, respectively, and at least one end of the knockout is easily and quickly fractured. The pliers in accordance with this invention could also include an adjustable interconnecting mechanism and could be used for a wide range of other purposes. Therefore, this invention is not limited to the usages described herein.
The foregoing features and advantages of the present invention will be apparent from the following more particular description of the invention. The accompanying drawings, listed hereinbelow, are useful in explaining the invention.
REFERENCES:
patent: 354313 (1886-12-01), Galloway
patent: 1585903 (1926-05-01), McIntyre
patent: 1664081 (1928-03-01), Means
patent: 2948171 (1960-08-01), Lucibello
patent: 3357460 (1967-12-01), Gawura
patent: 4014226 (1977-03-01), Karamarkovich
patent: 4890519 (1990-01-01), Le Duc
patent: 4901609 (1990-02-01), Crum
patent: 5011491 (1991-04-01), Boenko et al.
patent: 5058414 (1991-10-01), Hayes
patent: 5134908 (1992-08-01), Fisher
patent: 5283936 (1994-02-01), Pickles et al.
patent: 5676029 (1997-10-01), Putsch
Carrillo Michael A.
Danganan Joni B.
McDonough Thomas C.
Scherbel David A.
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