US2262084A

US2262084A - Metal testing machine

Info

Publication number: US2262084A
Application number: US369901A
Authority: US
Inventors: Alexander James Wolfe
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-11-28
Filing date: 1940-12-12
Publication date: 1941-11-11
Anticipated expiration: 1958-11-11

Description

Nov. 11, 1941. J w ALEXANDER 2,262,084

METAL TESTING MACHINE Filed Dec. 12, 1940 5 Sheets-Sheet 1 Fig.1

Nov. 11, 1941. J. w. ALEXANDER METAL TESTING MACHINE Filed Dec. 12, 1940 5 Sheets-Sheet 2 Nov. 11,1941 J. w. ALEXANDER METAL TESTING MACHINE Filed Dec. 12, 1940 3 Sheets-Sheet; 3

Fig.4

Patented Nov. 11, 1941 UNITED sr TESPATE QFFICE Application December 12, 1940, Serial No. 369,901 In Great Britain November 28, 1939 2 Claims.

This invention relates to metal testing machines of the kind in which a specimen sheet is forced into or through a die by a punch.

The object of the present invention is to provide a simple and convenient means whereby a graphic record can be made of both the pressure exerted on the specimen and the relative axial movement of the punch and die.

The invention comprises the combination of a torsionally resilient rotary driving means for eifecting the relative movement between the punch and die, a style and operating mechanism therefor carried on and operable by the said means, and a stationary chart holder mounted or adapted to be mounted adjacent to the style.

In the accompanying sheets of explanatory drawings:

Figure 1 is a sectional front elevation and Figure 2 a plan of a metal testing machine embodying the invention, Figure 1 being a section on the line l-l of Figure 2.

Figure 3 is a section on the line 33 of Figure 1.

Figure 4 is a fragmentary side view of the style and driving means looking from the right of Figure 1.

In carrying the invention into effect as shown, I employ a testing machine comprising a hollow body part a having mounted in its open upper end a stationary tool in the form of a die I) through which can pass a movable toolin the form of a punch c on the upper end of a vertical plunger d. The upper portion of the plunger d is screw threaded and engages a complementary screw thread in an axially movable but non-rotatable nut or sleeve e having at its upper end an annular support 1 for the flat sheet metal specimen 9 to be tested, the punch being arranged to pass through the specimen support. The sleeve e extends through and is in screw thread engagement with a worm wheel h which is held against axial movement on a shoulder or bush 2' in the body part a by a stationary retaining ring 7' surrounding the sleeve, this ring being provided with a key k which by engagement with a longitudinal groove m in the sleeve serves to prevent rotational movement of the latter. The worm wheel 72. is in engagement with a worm n on the inner end of a spindle 0 which extends through the front of the body part a, and which is provided at its outer end with an operating hand wheel 12. For determining the relative positions of the plunger d and sleeve e preparatory to a testing operation being performed on the specimen g, a catch member q in the form of an axially slidable horizontal rod is mounted on and extends through one side of the body part a, this catch member being loaded by a spring 1 which tends to move it into an operative position in which its inner end can pass through a hole s in the sleeve into a blind hole in the plunger and thereby hold the latter and the sleeve stationary. At its outer end the catch member q is provided with a finger piece or knob 11. whereby it can be moved against the action of its loading spring 1- into an inoperative position clear of the plunger d and sleeve e. Normally the catch member 11 is held in its inoperative position by the engagement of a projection 12 on the catch member with a recess '11; at the outer end of a slot :r in a fixed guide :1 through which the catch member extends. To bring the sleeve e and plunger cl into the positions in which they can be held by the catch member q, the hand wheel p is first actuated for imparting to the sleeve the axial movement required to bring the hole 8 in the sleeve into a position in which it can be engaged by the catch member. The plunger d is then rotated in the manner hereinafter described until the blind hole 8 in the plunger is engaged by the inner end of the catch member q. The plunger d and sleeve e now occupy positions in which the upper end of the punch a on the plunger and the upper side of the specimen support 1 on the sleeve lie flush with each other and adjacent to the underside of the die 17. If it is now required to perform a testing operation on the specimen g, the catch member (1 is moved to its inoperative position clear of the plunger (1 and sleeve e, and the hand wheel 11 is again actuated for moving the sleeve axially into a position in which the specimen is clamped between its support and the underside of the die b, this movement of the sleeve being accompanied by similar movement of the plunger due to the screw thread connection between these parts. The plunger 01 is then rotated relatively to the sleeve e and is thereby caused to move the punch c axially for forcing the specimen g through the dieb, the extent of the relative movement that occurs between the punch c and die b before the specimen is fractured serving as a measure of the ductility of the specimen.

For enabling the required rotary movement to be imparted to the plunger (1, the lower end of the latter is slidable through and splined to a rotatable sleeve 2 (hereinafter termed the driven member) which is supported by ball bearings 3 in the lower portion of the body part a. Coaxially with and adjacent to the driven member 2 there is freely mounted in the body part a a rotatable member 4 (hereinafter termed the driving member) which in the example shown has the form of an annular worm Wheel, and which is engaged by a worm 5 on the inner end of a spindle 6 extending through the front of the body part, the outer end of this spindle being provided with a hand wheel 1 whereby the driving member can be rotated. Alternatively the driving member may be adapted to be rotated by power. The underside of the driving member 4 is provided with a pair of projections 9 whereby rotational movement can be transmitted from the driving member to the driven member 2 through any convenient springs as Ill of sufficient strength to enable the required turning effort to be imparted to the plunger d. In the example shown the springs are contained in, and carried by slidable rods extending through, housings l2 at the outer ends of a pair of radial arms |3 on the driven member 2, the rods being adapted at one end to be acted on by the projections 9 on the driving member 4, and being provided with collars l4 adapted to act on the springs. On one of the radial arms |3 of the driven member 2 there is pivoted at IS a lever having a long arm l6 and a short arm IT. The latter arm of the lever is adapted at its outer end to be acted on by the adjacent projection 9 on the driving member 4, so that relative angular movements of the driving and driven members 4, 2 cause the lever to be moved about its pivot axis under the control of any convenient loading spring I8 to move the lever l6, l1 into a position in which the long arm l6 abuts against an adjustable stop |9 on the lever supporting arm |3. On the outer end of the long lever arm H is mounted any convenient style 20, such as a pen or pencil, for drawing a line on a chart (not shown) carried by a table or holder 2|. Preferably and as shown the part of the lever arm l6 which carries the style 20 is made separately from and connected by a horizontal pivot pin 22 to the other part of that arm, so that the style can rest on the chart.

The table or holder 2| is supported at a position beneath and adjacent to the style 29 on the upper end of a vertically adjustable carrier 23, the latter being mounted in any convenient stationary support 24. At one side the carrier 23 is provided with a vertical toothed rack 25 which is engaged by a pinion 26 on the inner end of a spindle 26" extending through the front of the support 24, the outer end of this spindle being provided with a hand wheel 21 whereby the spindle can be rotated for effecting vertical adjustment of the carrier through the interaction of the rack and pinion. Depending from the underside of the table or holder 2|, is a cylindrical member 28 which is accommodated in a corresponding aperture 29 in the carrier 23, and which permits the table or holder to be adjusted about a vertical axis. For adjustably securing the table or holder 2| to the carrier 23 any convenient clamping means are employed. Such means in the example shown are carried by the support 24 and comprise a pair of

clamping members

30, 3| arranged end to end and shaped at one side to embrace a part of the cylindrical member 28 depending from the table or holder 2 The clamping member 30 is formed or provided on the inner end of a spindle 33 which passes through a bore in the other clamping member 3| and extendsfrom the front of the support 24. The outer end of the spindle 33 is screw threaded and carries a nut 34 provided with an operating hand lever 35, the nut being adapted to act on the adjacent end of the clamping member 3|. By appropriate manipulation of the operating lever 35 the

clamping member

30, 3| can be caused to grip or release the member 28 depending from the table or holder 2|.

In the example shown the body part a is car- This spring tends ried on the support 24 by short vertical members 36 which serve to interconnect the body part and support.

When the machine above described is in use, the style 20 draws on the chart a line which serves to record the main features of the test. Relative angular movement of the driving and driven members 4, 2 under the action of the force applied to the spindle 6 causes the line drawn by the style 20 to move away from a given datum circle on the chart and so gives a measure of that force. When the specimen 9 fractures the force required to move the plunger (1 falls and the line consequently returns more or less suddenly towards the datum circle. From the shape of the line, the yield point of the specimen 9 can be ascertained, and the length of the line up to the point indicating fracture serves as a measure of ductility.

If desired a graduated disc 31 may be employed for indicating the extent of the angular movement imparted to the spindle 6 by the force to be measured. The spindle B is arranged to pass through a central hole in the disc 31 which is mounted on the front of the body part a so as to be capable of angular adjustment relatively to an index mark on the spindle or a part carried by the spindle.

The invention is not limited to the example above described as subordinate mechanical or constructional details may be varied. 7

By this invention the required record of the testis obtainable in a very simple and convenient manner.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A metal testing machine comprising the combination of a punch, a stationary die into or through which a metal specimen can be forced by the punch, a rotatable and axially movable plunger carrying the punch, a non-rotatable sleeve carrying the plunger, the sleeve having a screw thread connection with the plunger so that rotation of the latter is accompanied by axial movement thereof, torsionally resilient driving means consisting in part of rotatable but axially immovable driving and driven members and in part of spring means for transmitting movement from the driving member to the driven member, the plunger having a slidable connection with the driven member so that the plunger is rotatable by but capable of axial movement relatively to the driven member, a style, a lever carrying the style, the lever being mounted on one of the said members, means on the other of the said members for operating the lever in response to relative movement between the said member, and a stationary chart holder which is situated adjacent to the style and over which the style is movable for recording on a chart carried by the holder the motion of the driving means and the relative movement between the driving and driven members.

2. A metal testing machine as claimed in claim 1 and having in combination a hollow body part in which the die, the sleeve carrying the plunger, and the torsionally resilient driving means are mounted, a stationary support carrying the body part and the chart holder, means for adjusting the position of the chart holder, and clamping means for securing the chart holder in the desired position.

JAMES WOLFE ALEXANDER.