Patent Application
20140035214
The present invention relates generally to fixtures and more particularly relates to a self-locking fixture for adjustably positioning a work piece relative to a machine.
Fixtures are commonly used to hold and position a work piece relative to a machine for various applications. For example, in the testing or machining industries, a fixture may be used to position and hold a work piece steady while a machine acts upon the work piece. In such applications, particularly those involving partially automated machines, there is often a desire to optimally position the work piece relative to the machine in order to achieve a correct and accurate test reading or a precise material working. Accordingly, known fixtures may provide a degree of adjustability that allows the work piece to be held in multiple positions relative to the machine.
For example, known dovetail-type fixtures that allow for adjustment along an axis may include engageable threads or teeth on the dovetail for locking the work piece at discrete positions relative to the machine. However, the adjustability of such fixtures may be limited to movement along a single axis and may be further limited to the discrete positions dictated by the pitch of the threads or teeth. Additionally, optimal positioning of the work piece using such fixtures may be cumbersome and time-consuming because of the need to engage the threads or teeth with mating structure, and perhaps the need to disengage and reengage the features if further adjustment is necessary. Time spent positioning the work piece equates to time that the machine is not doing useful work, which may result in a productivity loss of the testing or machining operation. Furthermore, incorporating, mating structure that releaseably engages the threads or teeth often results in a fixture that is too complex and bulky to be used for certain applications, particularly those involving work pieces that are small or miniature.
There is a desire for a fixture having improved adjustability for optimally positioning a work piece at any position along multiple axes relative to a machine. Such an improved fixture should be simple, compact, and easy to use in large-scale or small-scale applications. Such an improved fixture also should allow for quick positioning of the work piece and locking of the fixture once an optimal position has been reached, without the need to engage manually a locking feature.
The present application provides a self-locking fixture for adjustably positioning a work piece relative to a machine. The self-locking fixture may include a first base, a work piece holder slideably connected to the first base, and a first resistance element for resisting the work piece holder sliding relative to the first base.
The present application further provides a method of positioning a work piece relative to a machine. The method may include the steps of inserting the work piece into a work piece holder located near the machine, sliding the work piece holder along a first axis relative to the machine and a first base, locking the work piece holder along the first axis, sliding the first base along a second axis relative to the machine and a second base, and locking the first base along the second axis.
The present application further provides a self-locking fixture for adjustably positioning a work piece relative to a machine. The self-locking fixture may include a first base, a work piece holder, a first resistance element, a second base, and a second resistance element. The work piece holder may be slideably received by the first base and may be able to slide along a first axis relative to the first base. The first base may be slideably received by the second base and may be able to slide along a second axis relative to the second base. The first resistance element may be able to lock the work piece holder at any position along the first axis relative to the first base. The second resistance element may be able to lock the first base at any position along the second axis relative to the second base.
These and other features and improvements of the present application will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.
Referring now to the drawings, in which like numerals refer to like elements throughout the several views,
The self-locking fixture 100 also may include a second base 400 connected to the first base 200. The second base 400 may include a first end portion 410 and a second end portion 420. The first end portion 210 of the first base 200 may be connected to the second end portion 420 of the second base 400. The first base 200 is preferably slideably connected to the second base 400, which connection may allow the first base 200 to slide along a second axis Y relative to the second base 400. Preferably, the second axis Y is not coincident or parallel to the first axis X. More preferably, the second axis Y may be perpendicular to the first axis X. Consequently, a work piece 10 that is received by the second end portion 320 of the work piece holder 300 may also move along, or parallel to, the second axis Y relative to the second base 400.
The work piece holder 300 preferably may include a biasing element 370 connected to each of the holder portions 330, 340, which biasing element 370 is able to draw the holder portions 330, 340 toward one another. The biasing element 370 may be an extension spring, elastic band, or other known device for drawing components toward one another. The biasing element 370 may be connected to each of the holder portions 330, 340 by a pin connection, a weld, or other known fastening connection. Upon insertion of the work piece 10 between the holder portions 330, 340, the biasing element 370 draws the holder portions 330, 340 toward one another to ensure that each of the holder portions 330, 340 contacts an opposite surface of the work piece 10. The biasing element 370 may be selected to provide sufficient force drawing the holder portions 330, 340 toward one another such that the work piece 10 may be securely held between the holder portions 330, 340 at any position along the longitudinal grooves 350 of the holder portions 330, 340. In other words, the frictional forces generated between each of the holder portions 330, 340 and the opposite surfaces of the work piece 10 are sufficient to secure the work piece 10 when the work piece 10 does not contact the lateral grooves 355 of the holder portions 330, 340. However, such frictional forces may be temporarily overcome by manually moving the work piece 10 along a third axis Z relative to the work piece holder 300. The third axis Z preferably may be perpendicular to each of the first axis X and the second axis Y.
The first end portion 310 of the work piece holder 300 preferably may be slideably connected to the second end portion 220 of the first base 200 by a dovetail connection. As shown in
In a similar manner, the first end portion 210 of the first base 200 may be slideably connected to the second end portion 420 of the second base 200 by a dovetail connection. As shown in
The self-locking fixture 100 preferably may include one or more first resistance elements 500 that are able to resist sliding of the work piece holder 300 relative to the first base 200. The first resistance elements 500 may be ball plungers 505, compression springs, or other known devices for resisting movement between slideably connected components. As shown in
In a similar manner, the self-locking fixture 100 may include one or more second resistance elements 600 that are able to resist sliding of the first base 200 relative to the second base 400. The second resistance elements 600 may be ball plungers 605, compression springs, or other known devices for resisting movement between slideably connected components. As shown in
The above-described example of the self-locking fixture 100 having the, first base 200, the work piece holder 300, and the second base 400 thus would provide improved adjustability for optimally positioning the work piece 10 relative to a machine. Specifically, the work piece 10 may be moved to any position along the first axis X, second axis Y, and third axis Z within the ranges allowed by the slideable connections of the self-locking fixture 100. Furthermore, the biasing element 370 and the resistance elements 500, 600 provide self-locking of the slideable connections, thus eliminating the cumbersome and time-consuming steps of locking manually the fixture 100 once an optimal position has been achieved or unlocking manually the fixture 100 if further adjustment is necessary. Overall, the self-locking fixture 100 incorporates a simple and compact design that would be easy to use in large-scale and small-scale testing or machining applications.
It should be apparent that the foregoing relates only to certain embodiments of the present application. Numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof.
