Abstract:
The disclosure relates to a specimen holder for a grip used in materials, or similar testing. The user can position a specimen or testing sample within the open jaw, and then remove his or her hands to a safe location before activating the grip to grip the specimen.

Description:
BACKGROUND OF THE INVENTION 
     This application is national phase of PCT/US2010/025078 filed Feb. 23, 2010, and claims priority under 35 U.S.C. §119 (e) of U.S. provisional application serial no. 61/165,203 filed Mar. 31, 2009. 
     1. Field of the Disclosure 
     The present disclosure pertains to a specimen holder for tensile or materials testing, which is mounted directly in the grip of the testing device. 
     2. Description of the Prior Art 
     In materials testing, the specimen or testing sample is typically gripped and then pulled or compressed in order to measure the material properties of the specimen. The gripping mechanism can be of several types, including the automatic side-action grip, which can be pneumatic or hydraulic. Typically, the user holds the ends of the specimen between the jaws of the grip and then actuates a switch, typically by the user&#39;s hand or foot, to cause the jaws to come together and to grip the specimen. The closing of the jaws is often fast and with enough force that, should the user&#39;s fingertips be between the jaws, the user can receive a severe pinch injury. This hazard increases as the jaw face opening increases because this allows more space for a user to insert a finger between the jaws. Industry practice with respect to grips with large jaw face openings is to slow the grip closing speed enough to allow sufficient time for the user to withdraw the finger. However, the slowing of the speed of the jaw face slows the productivity of the user. 
     It can therefore be difficult to place the specimen or testing sample into position accurately, while maintaining both safety and high work volume. 
     OBJECTS AND SUMMARY OF THE DISCLOSURE 
     It is therefore an object of the present disclosure to provide a device for materials testing, or similar devices, wherein the specimen or testing sample can be engaged and positioned within a grip by a device with low operating forces, thereby allowing the user to move to a safe distance from the grip before activating the grip. 
     This and other objects are obtained by providing a spring-loaded device that holds a specimen in position between the jaws of a grip in a materials testing, or similar machine, for the purpose of allowing the user to remove his or her hand from the grip before actuating the grip, while leaving the specimen in position. 
     The device of the present disclosure provides an apparatus and method by which a user can remotely operate a grip of a material testing, or similar, device without being exposed to the potentially severe pinch hazard from the grip jaw faces. 
     The device of the present disclosure employs a low-force spring mechanism with sufficient holding force to support the weight of the specimen. Additionally, the device includes an adjustable specimen stop to allow users to more quickly position the test specimen to a fixed location. The user is able to load a rigid specimen into the grips very quickly by simply pushing the specimen into the device until the specimen abuts an adjustable stop. The user can then simply let go of the specimen and it will remain in place while the user remotely actuates the grip. 
     Furthermore, the design of the holder allows the user to easily open the holder and keep the holder open while inserting a specimen. This is particularly useful when loading flexible specimens that cannot be pushed into the holder. 
     The hold is mounted on the grip and can be positioned close to the jaw face of the grip, on either side of the jaw face. In cases where the specimen holder must be positioned in the testing side (or gauge side) of the specimen, an optional pneumatic cylinder can be added to allow the specimen holder to automatically open once the grip force on the specimen reaches a certain preset point. This feature prevents any stray forces being induced into the specimen while it is undergoing testing. The same cylinder can then also reset to the holding position when the forces decrease to a preset point. 
     Finally, once the test is complete, the specimen holder may hold the broken ends of the specimen from falling from the grips. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further objects and advantages of the disclosure will become apparent from the following description and from the accompanying drawings, wherein: 
         FIG. 1  is a front perspective view of an embodiment of the specimen holder of the present disclosure, shown mounted in a grip. 
         FIG. 2  is a rear perspective view of an embodiment of the specimen holder of the present disclosure, shown mounted in a grip. 
         FIG. 3  is an exploded view of a further embodiment of the specimen holder of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings in detail wherein like numerals indicate like elements throughout the several views, one sees that  FIGS. 1 and 2  are respective front and rear perspective drawings of the grip  100 , including an embodiment the specimen holder  10  of the present disclosure.  FIG. 3  discloses a further embodiment of the specimen holder  10 . 
     As is known in the art, the grip  100  includes first and second jaws  102 ,  104  with respective first and second jaw faces  106 ,  108 . First and second jaw faces  106 ,  108  reciprocate toward and away from each other, and grip a specimen or testing sample (not shown) therebetween, typically compressing or expanding the sample in a direction parallel to the face of the jaw faces  106 ,  108 . 
       FIGS. 1 and 2  show that the specimen holder  10  includes a machined plate  12  which is secured to mounting block  14  so as to extend into the space between first and second jaws  102 ,  104 . The combination of the machined plate  12  and the mounting block can be considered to be a mount. As shown in  FIG. 3 , mounting block  14  may be secured to the rear of grip  100 , using conventional mounting hardware such as mounting screws  19 ,  21 . As further shown in  FIG. 3 , machined plate  12  may be adjustably mounted to mounting block  14  by providing mounting block  14  with slotted passageway  15  through which threaded pin  17  passes and can travel vertically therewithin. Threaded pin  17  further passes through an aperture in machined plate  12  and receives adjusting knob  23 . This configuration allows for the adjustment of the vertical position of machined plate  12 . Adjustable specimen stop  31  passes through machined plate  12  and is held in by specimen stop block  25 . The position of adjustable specimen stop block  25  is adjustable by way of adjusting knobs  27 ,  29 . As will be described herein, the adjustable stop  31  is used to accurately position, or to limit the position of, the specimen or testing sample (not shown) within specimen holder  10 . 
     The specimen holder  10  further includes first and second opposed specimen holding fingers  16 ,  18 , typically formed from bent metal wire or tubular steel or other metal. Those skilled in the art will recognize a wide range of equivalents after review of the present disclosure. The first and second opposed specimen holding fingers  16 ,  18  include respective first and second axle portions  20 ,  22  which pass through respective first and second apertures  24 ,  26  formed in machined plate  12  and are rotationally mounted therein thereby allowing the first and second specimen holding fingers  16 ,  18  to reciprocate toward and away from each other. Additionally, first and second inter-engaging gears  28 ,  30  are affixed to respective first and second axle portions  20 ,  22  immediately to the rear of machined plate  12 . First and second inter-engaging gears  28 ,  30  cause the first and second specimen holding fingers  16 ,  18  to rotate an equal amount away from and toward the central location of the first and second specimen holding fingers  16 ,  18  illustrated in  FIGS. 1 and 2 . Additionally, the affixing of the first and second inter-engaging gears  28 ,  30  to the respective first and second axle portions  20 ,  22  longitudinally secures first and second axle portions  20 ,  22  within respective first and second apertures  24 ,  26  thereby preventing the removal thereof. 
     As shown in  FIG. 2 , first inter-engaging gear  28  includes a radially-extending spring mounting stud  32 . Spring  34  includes a first end  36  secured to the machined plate  12  and a second end  38  secured to spring mounting stud  32 . Spring  34  serves to rotationally bias the first and second specimen holding fingers  16 ,  18  to hold a specimen or testing sample (not shown) therebetween, thereby allowing the user to remove his or her fingers prior to activating the first and second jaw faces  102 ,  104 . The strength of the spring  34  is chosen so as to provide sufficient engaging strength of first and second specimen holding fingers  16 ,  18  for securing the specimen or testing sample (not shown) while allowing simple manual manipulation by the user and not presenting a physical hazard to the user. 
     Distal ends of first and second specimen holding fingers  16 ,  18  further include respective first and second downwardly extending portions  40 ,  42 , generally perpendicular to respective first and second axle portions  20 ,  22 . Respective first and second sample holding portions  44 ,  46  extend perpendicularly (i.e., horizontally in the orientation illustrated in  FIGS. 1 and 2 ) from first and second downwardly extending portions  40 ,  42  and generally parallel to first and second axle portions  20 ,  22 . First and second sample holding portions  40 ,  42  are illustrated engaging each other in  FIGS. 1 and 2 , as a result of the biasing provided by spring  34 . Typically, the specimen or testing sample (not shown) is engaged between first and second sample holding portions  44 ,  46  with a position buttressed by adjustable speciment stop  31 . First and second sample holding portions  44 ,  46  further include respective first and second outwardly flared portions  48 ,  50  thereby forming V-shaped lead  52  which allows a user to simple push a specimen or testing sample therebetween, thereby spreading the first and second specimen holding fingers  16 ,  18  apart by the manual force applied to the specimen or testing sample and positioning the specimen or testing sample between first and second sample holding portions  44 ,  46 . Furthermore, adjustable stop  31  (see  FIG. 3 ) can be positioned above or otherwise adjacent to the first and second specimen holding fingers  16 ,  18  for aiding in positioning the specimen or testing sample (not shown) by limiting the insertion of the specimen or testing sample. First and second downwardly extending portions  54 ,  56  extend downwardly from respective first and second outwardly flared portions  48 ,  50  thereby providing the user with a convenient way of manually rotating the first and second specimen holding fingers  16 ,  18 . 
     As generally described above, in order to use the specimen holder  10  of the present disclosure, the user typically separates the first and second jaw faces  106 ,  108 , inserts a specimen or testing sample (not shown) between first and second specimen holding fingers  16 ,  18  so that the specimen or testing sample is held in place. The specimen or testing sample may be inserted so as to abut the adjustable stop  31  thereby positioning the specimen or testing sample. The user then removes his or her fingers and any other extremities safely away from the grip  100  and activates the grip  100  so that first and second jaw faces  106 ,  108  grip the specimen. Materials testing, such as tensile testing, can then be commenced. 
     Thus the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.