Patent Application
20070130776
The present disclosure is directed to a shear, and more particularly, to a heavy duty shear having a replaceable shearing tip.
A conventional heavy duty shear typically employs relative movable upper and lower jaws with shear blades of hardened steel on both the upper jaw and the lower jaw. The distal end of the jaw members is provided with a cutting and piercing tip by which a workpiece is pierced and severed during closure of the one jaw member relative to the other. Such jaw tips are subject to extreme wear and accordingly require frequent replacement. Replacement of the tips is expensive both from the standpoint of the cost of the tip and the down time required to remove, repair and reconnect a damaged or worn tip or, if beyond repair, to replace with a new tip component. Accordingly, repairing or replacement of the tip is required each time the piercing and cutting edges become worn or damaged, whereby maintenance costs and down time are undesirably high.
In addition, high lateral forces are exerted on the tip, great tension is also exerted upon the tip, and direct shear bearing loads are also applied to the tip when shearing. All these factors will cause a removable tip to easily break off the upper jaw.
U.S. Patent Publication No. 2004/0093739 provides a shear having a replaceable shearing tip. The shearing tip of 2004/0093739 only has one cutting edge, and therefore, the shearing tip has to be replaced once this single cutting edge is worn. In addition, the shearing tip of 2004/0093739 is mounted to the upper jaw by screws, and those screws may easily break off the upper jaw.
The shear with a replaceable shearing tip of the present disclosure solves one or more of the problems set forth above.
In one aspect, the present disclosure is directed to a replaceable shearing tip for using with a shear. The shear has a fixed lower jaw and a movable upper jaw pivotally connected to the lower jaw. The upper jaw has a left portion, a right portion, a front portion between the left portion and the right portion, and a replaceable shearing tip mounted on the upper jaw. The replaceable shearing tip includes a left part having two edges, a mounting section extending between the two edges for mounting the left part on the left portion of the upper jaw, and a front section connected to the mounting section for covering the front portion of the upper jaw. The shearing tip also includes a right part having two edges, a mounting section extending between the two edges for mounting the right part of the shearing tip on the right portion of the upper jaw, and a front section connected to the mounting section for covering the front portion of the upper jaw. The left part and the right part are interchangeable. In one embodiment, the left part and the right part are substantially identical. In one embodiment, the two edges of the left part are symmetrical, and the two edges of the right part are symmetrical.
In one aspect, the present disclosure is directed to a method of replacing a shearing tip on an upperjaw of a shear. The upper jaw has a right portion, a left portion, and a front portion between the right portion and the left portion. The method includes disassembling a right part of the shearing tip from the right portion of the upper jaw, and disassembling a left part of the shearing tip from the left portion of the upper jaw. The method also includes mounting the right part of the shearing tip to the left portion of the upper jaw, and mounting the left part of the shearing tip to the right portion of the upper jaw.
As shown in
As shown in
An example of the left part 40 or the right part 50 is shown in
The replaceable shearing tip 30 may be made of a hard metal, for example, hardened steel.
The disclosed replaceable shearing tip may be applicable to any shear that includes demolition shears and scrap shears. The operation of the replaceable shearing tip will now be explained.
The shearing tip 30 has two interchangeable parts including a left part 40 and a right part 50. In one embodiment, the left part 40 and the right part 50 are substantially identical. The left part 40 has two symmetrical cutting edges including an upper edge 42 and a lower edge 44. The right part 50 has two symmetrical cutting edges including an upper edge 52 and a lower edge 54. The tip 30 is mounted on the upper jaw 14. The lower edges 44 and 54, which are mounted at a distal end 100 of the upper jaw, may be worn after a period of time of use. The left part 40 and the right part 50 of the tip 30 can be disassembled from the upper jaw 14. The left part 40 of the shearing tip 30 can be turned upside down and installed on the right portion 18 of the upper jaw 14 in a reversed position. In other words, the left part 40 of the shearing tip 30 may be installed to the right portion 18 of the upper jaw 14 with the lower edge 44 in a proximal position and the upper edge 42 at the distal end 100 of the upper jaw 14. Similarly, the right part 50 also can be turned around and installed on the left portion 16 of the upper jaw 14 in a reversed position. Thereby, the upper edges 42 and 52 at the distal end 100 of the upper jaw 14 can be used for another period of time before the shearing tip 30 is worn out and needs to be replaced by a new shearing tip.
Several advantages over the prior art may be associated with the disclosed replaceable shearing tip 30. The tip 30 is mounted to the upper jaw 14 by bolts 60, and therefore, the tip 30 can be easily mounted on and dissembled from the upper jaw 14. The replaced shearing tip 30 further has bushes 80, and the bolts 60 are received in the bushes 80, which lock the tip 30 to the upper jaw 14, and prevent the tip 30 from breaking off the upper jaw 14 despite high direct and lateral forces, as well as shearing and tensional forces exerted on the tip 30. The tip 30 also covers the complete front portion 20 of the upper jaw 14, and therefore, protects the front portion 20 of the upper jaw 14 from wearing. The tip 30 includes two interchangeable parts 40 and 50, each having two symmetrical cutting edges. After a first set of edges is worn, the two interchangeable parts 40 and 50 can be turned around and installed on the other side of the upper jaw 14 in a reversed position, so that a second set of edges can be used. Therefore, the tip can be used twice and has a longer life time.
It will be apparent to those skilled in the art that various modifications and variations can be made to the shear with replaceable shearing tip. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed shear with replaceable shearing tip. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.
