Patent Application
20060070501
This invention relates to a precision shear for the removal of material from metallic parts, and more particularly, to a precision shear which has the ability to remove undesirable machining tabs from finished metallic parts in a quick and efficient manner.
Many aerospace aluminum and titanium parts are fabricated by machining from a solid billet or hand forging. In most cases the finished part is held in place by leaving a surrounding frame of solid material and leaving tooling tabs to hold the finished part within the surrounding frame. Typically this picture frame is cut away with a band saw, abrasive wheel or other method. Then the remaining sections of the tooling tabs must be cut away. This is typically done by hand grinding and sanding operations.
The deburring and finishing of the tooling tabs can be a time consuming process and can consume as much as 20% of the total cycle time for fabricating a part.
Currently removing tooling tabs from a picture-framed metallic machined part requires die grinding and hand sanding operations. These hand operations can be time consuming, hazardous and imprecise. Grinding operations produce fine metallic particles and special stations must be used to collect and dispose of these particles to prevent inhalation.
As can be seen, there is a need for a device that can quickly and precisely remove the unwanted portions of a work piece. There is also a need for a simple and efficient means to remove tooling tabs from a picture-framed metallic part. Moreover, there is a need for a finishing method that quickly and precisely cuts away the tooling tabs leaving only the finished part and does not require additional hand blending or sanding operations. In addition, there is a need for significantly reducing or completely eliminating the airborne particles produced in finishing operations.
In one aspect of the invention, an apparatus for shearing material is provided comprising a scissor mechanism comprising a first handle pivotably connected to a second handle. Also provided is a first jaw associated with the first handle and a second jaw associated with the second handle. A cutter is disposed between the first and second jaw, and the cutter is configured to cut through a predetermined thickness of material as the first jaw and the second jaw are moved to a closed position. An alignment surface configured to align with the cutter at a predetermined position in relation to a workpiece is also provided and a support is provided which is configured to buttress the workpiece as the cutter is forced through the material.
In another aspect of the present invention, a precision shear for removing tabs from a picture-framed metallic machined part is provided which comprises a first handle having a first jaw and a second handle having a second jaw. A pivot is disposed on the first handle and the second handle, wherein the pivot is configured to move the first and second jaws selectably to an open and closed position. A cutter mechanism is provided that is disposed intermediate the first and second jaws, and the cutter mechanism is configured to remove the tabs from the machined part. Also provided is an alignment surface configured to align the cutter along a predetermined position in relation to the machined part and a spring is provided which is configured to bias the first jaw and the second jaws to an open position.
In yet a further aspect of the present invention, a method for shearing material is provided that comprises the steps of providing a scissor mechanism comprising a first handle pivotably connected to a second handle. A first jaw associated with the first handle and a second jaw associated with the second handle is provided and a cutter is disposed between the first and second jaw, where the cutter is configured to cut through a predetermined thickness of metal as the first jaw and the second jaw are moved to a closed position. An alignment surface is configured to align the cutter at a predetermined position in relation to a workpiece and a support is configured to buttress the workpiece as the cutter is forced through the material to be sheared. Next, the cutter is aligned with the material to be removed and pressure is applied to the first and second handle to force the cutter through the material to be sheared.
In a still further aspect of the present invention, a device for the removal of material from a machined metal part is provided which comprises a cutter vertically opposed from a support. Also provided is a scissor mechanism configured to move the cutter toward the support. An alignment surface is configured to align the cutter with the material to be removed from the machined metal part wherein the cutter is forced through the machined part to remove material thereby producing a finished machined part that requires little or no finishing operations.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description, and claims.
The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
The precision shearing device described herein is suitable for use for the production of machined metal parts. More specifically, the precision shear lends itself particularly well to the removal of machining tabs that require precision removal from a machined part thereby reducing or eliminating the need for finish grinding or polishing. In addition, the device may be operated by hand or adapted for use with a hydraulically or pneumatically powered apparatus.
The precision shearing device described herein provides a unique means for the quick and economical removal of unwanted material from a finished machine part. The device provides an alignment feature which allows the operator to quickly and easily determine the cut line which will require little or no additional grinding or polishing. The prior art required the use of large machines such as a band saw to remove the unwanted material. Typically, the use of a band saw or other method would also require additional finish machining operations such as filing or polishing to produce an acceptable part. The unique cutter provided with the current device is configured to produce a clean cut through the cut line that leaves an edge along the finished part that meets the finish requirements of the machined part. The unique high strength cutter is held in precise alignment with the desired cut line and the cutter is configured to produce an accurate, clean cut through the material.
Referring now to
A cutter 16 and a support 20 are vertically opposed from one another. The cutter 16 may be in contact with the first jaw 14a and the support 20 may be affixed to the second jaw 14b. With the first jaw 14a not affixed to the cutter 16, the force applied to the cutter 16 can be optimized to eliminate any rotating moment that may act to bind the cutter 16 as it moves up and down. The support 20 is configured to buttress the work piece 30 and may extend from the plane of the cutter. A pair of tabs 25 extend from the cutter 16 and are configured to be slidably received by a respective pair of slots 24 that are disposed on a respective first bar 18a and a second bar 18b. The tabs are configured to maintain the alignment of the cutter 16 as it is forced through the material that is to be removed from the work piece 30 thereby creating a clean cut which requires little or no finishing. A base 26 and a top bar 22 extend across the width of the cutter 16 to affix the location of the first and second bar 18a and 18b.
An optional resilient material (not shown) may be provided that acts to bias the shear to the open position. This resilient material may be a spring or an elastomeric material. Typically, this resilient material would be disposed between the first jaw 14a and the second jaw 14b and would force the jaws to an open position to allow insertion of the material to be removed.
Referring now to
It is also contemplated that an embodiment of the present invention may allow the shear 10 to be installed in machinery such as a pneumatic or hydraulically powered press which would allow the removal of thicker material as well as increase the speed at which the shear 10 operates.
Referring again to
Once the flange 32 is placed beneath the cutter 16 and surface 36 is abutted against first and second bar 18a and 18b, the operator will apply closing pressure to the first and second handle 12a and 12b and force the cutter 16 through the material along the cut line 34. In this manner, the operator has quickly and easily removed unwanted material from the machined work piece 30 without the need for finish grinding or polishing.
It should be understood, of course, that the foregoing relates to preferred embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
