US2424177A

US2424177A - Tensile testing machine

Info

Publication number: US2424177A
Application number: US569942A
Authority: US
Inventors: Walter D Lawshe; Winston A Gardiner
Original assignee: Monsanto Chemicals Ltd
Current assignee: Monsanto Chemicals Ltd; Monsanto Chemical Co
Priority date: 1944-12-27
Filing date: 1944-12-27
Publication date: 1947-07-15
Anticipated expiration: 1964-07-15

Description

July l5, 1947. w.'D. I AwsH-E Er AL TEFISLE TESTING MACHINE Filed Dec. 27, 194,4 "5 sheets-sheet 1` www# 5 Sheet-s--Sheet 2 iiillllll lellirl 11| A N |11 1 1H.I Q C @New AM NemNf/Hfkmw www l I J July 15, 1947.

w. D. `rI Awsl-ue: Er'ALj .TENSILE TESTING MACHINE --Filed Dec. 27, 1944 July 15, 1947; W.` D.` AwsHE ET Ap 2,424,117

TENSILE TESTING MAC-HINE Filed Dec. 27. 1944 5 sheets-sheet s INN.' .7 i Lfivf /AYNwAW /XMW j V/Kr LAN/ |/1 VNN 4 NW1/f Vlv /4 VQXX M14/WAH V/M/.JM/ fYWA W m W w H Mll NN.\\\\- \\.\\m. MHMlJMw "M1111 @NN we W :l: www@ N 4-1% E [lll ||||lf 1 1 -l lN 5M N .4. \ll .IWT r l N e n mw HN m 1| E .QN @N oww W om NN W Si 4.312. mw .4 Ill.| I l mW NW 1 1mm/@ l A, Qn w ww E b Wk, ww w @u we mun v s @v s v R NNN.

July 15, 1947.

w. D. LAwsHE Er Al. 2,424,177

TENSILE TESTING MACHINE Filed Dec. 27, 1944 5 sheets-sheet 4 10.1'r 11.1 11o' 117, li 117 July 15, 1947. W. D. LAWSHE Er Ax.-

TENSILE TESTING' MACHINE 5 Sheets-Sheet 5 Filed D60. 27,. 1944 gf---f- A lPatented July 15,1947 y 2,424,177 'rENsrLE 'rEs'rmG MACHINE Walter D. Lawshe and Winston A. Gardiner; Seattle, Wash.l assignors. ments, to Monsanto Chemical Company,

by mesne assign- Seattle, Wash., a corporation of ADelaware y Application December 27, 1944, Serial No. 569,942

' design.

In the drawings,

AFigure 1 is an isometric front view of an embodiment of the invention particularly designed for the purpose above mentioned.

Figure 2 is a plan view of the apparatus of Figure 1.

'Figure 3v is a of Figure 2.

Figure 4 is a section substantially on line 4-4 -section substantially on line 3-1-3 of Figure 3.

Figure 5 is a section substantially on line 5-5 of Figure 3.

Figure 6 shows a detailin elevation, and

Figure 'l is an elevation, partly in vertical section, of the main body of the apparatus showing the parts in a diierent relation from that shown in Figure 3.

Referring to the drawings, the apparatus comprises a cylindrical metal base I shown as iliied on a table II through front and rear. spacing blocks I2 and I3, the body being bolted in position through a base flange I4.

The body I0 is provided with a central vertical bore I formed in a horizontal web IE and a down? wardly projecting ilange Il thereof. Bolted and gasketed against the lower horizontal face of flange I'I is a plate or head I8 having a central vertical opening in which is secured and welded a cylindrical member I9 having a closed lower end 20. The upper endV of member I9 projects above the head I8 to provide an annular charnber 2 I.

Slidable in the cylinder i5 is a piston 22 having a depending shank 23 which is guided in bushings 24 and 25 which adjacent the inner wall otV member I9, have vertical' passages as at 25 and 21. 4A leather 28 is flxed to the bottom of pis ton-22 through-a ring 29:* i

Threaded in an openingi 39 in head I8 is a iitting 3l into which is vconnected a pipe 32 for conducting hydraulic pressure to'thevchamber 2l" and the source of pressure maybe thel ordinary city vrwater system as controlled by a rotary three Yway valve33, Figures rland 2, which is in con (Cl. 'i3-97) nectlon with the supply through a pipe 34. Reference-numeral 32' designates a needle valve in pipe 32 for adjusting the i'low to the hydraulic chamber. Reference numeral 35 designates a vent duct formed in head I8 and member I9 which is closed by a plug 36 after water has been admitted to displace the air from cylinder I5 and member I9. It will be seen that the water pressure will act in chamber 2l and also against the 'bottom of shank 23, the latter action being permitted by the

passages

26 and 21.

An assembly 31 comprises a plate 38 having a bottom cavity 39 rimmed by an annular shoulder against which a diaphragm 40 is clamped by means of a ring 4I which surrounds the upper reduced end of piston 22 with a close sliding t. Plate 38 has a radial port 42 leading into chamber 39 and having threaded in its outer end a that of piston 22.

against plate 54.

length of pipe 43 which is freely received in a lateral opening 44 of the base l0. An adapter 45 connects pipe 43 with a coil of flexible tubing 46 which extends to a pipe 41 in connection with .a fitting 48 in connection with a pressure gauge `49. Also in connection with fitting 48 is an elbow 59 having an upwardly extending portion provided with a threaded closure cap 5I. The described connections together with /c'hamber 39 lare illled with a suitable liquid through the elbow 59, air being vented through a radial port 52 in plate 38, the port being then closed by a plug 53. When the gauge system is filled with liquid, the diaphragm 40 is conformed to the concave top of piston 22 in the manner indicated in Figure '7. It will be observed that the piston 22 is just in contact with the diaphragm and that the piston can move lupwardly relative to assembly 3l by stretching the periphery of that portion of rthe diaphragm which is in contact with piston 22 into the chamber 39 whose circular peripheral wall 39' has a diameter at least no smaller than Such upward relative move'- ment is transmitted by the liquid above the dlaphragm to the gauge. l

A platel is secured to the horizontal upper edge of the base Ill and has secured thereto by a screw 55 a round bar 56, the bar being arranged on a diameterr ofv plate 54 and being disposed above and parallel tothe latter through a spacer 5l. The ends of bar 55 are receivedin aligned bores of blocks 58 and 59 which are rigidly bolted Block 58 has a bore 60 above-bar 5G, the axis of the bore being parallel to the axis of the bar and in the same vertical plane. A shaft El is rotatable in bore 69 and has an inner threaded end en- /gaged' in a threaded bore of a jaw block 62 which is slidable on bar 56, the block having secured to its inner end a horizontally serrated insert 63 whose teeth are preferably downwardly directed.

Extending outwardly from Iblock 58 is a pair of horizontally spaced

parallel arms

84 and 65 which terminatehin a Vertical plate or head B6 between which and a plate or head 61 is clamped a cylinder 68 on the axis of shaft 6l. Slidable in cylinder 68 is a piston 69 having a leather 10 clamped against its outer face through a spacer disc 1| by means of a central screw 12 which is threaded axially into a piston rod 13. A ring 14 is threaded into a central bore in head 66 and has an annular head 15 providing an inner annular edge against which bears one end of a compression spring 16 whose other end bears against piston 69. The projecting end of piston rod 13 has a circular head 11 bearing against a round head 18 on shaft 6| and coupled thereto by a swivel ring 19 which is secured to head 18 by means of a set screw 80.

The cylinder and piston unit is generally designated by the reference letter C.

In the relation of parts shown in Figure 3 spring 16 has pulled the jaw block 62 into abutment with block 58 and the spacer disc 1| in cylinder 68 is just out of contact with head 61. By appropriately turning the coupling disc 19 shaft 6| can be threaded outwardly of block 62 so that spring 16Y on bar 56 adjacent block 59 and has engagedtherewith the threaded end of a shaft 82 'which is journaled in block 59 coaxially with shaft 6| and is provided with an abutment collar 83 and with a knob 84. It will be evident that by turning the knob 84 appropriately the jaw block can be given a normal position in variablyspaced rela-k tion to block 59.

the support of the cross head and Aassociated parts. 1 i l `The cross head has secured thereto'a bar |05 exactly like bar 56 and parallel thereto and in the vaxial plane thereof. Fixed to the under side of the cross head are blocksl |06 and |01 in which are slidably journaled shafts |08 and l|09 which are exactly the same as shafts 8| and 82 and engage and ||3 which carry a cylinder and piston unit It will thus be seen that the space S between the jaws 62 and 8|, Figure 3, can be adjusted from either or both directions. In'th'e spaceS is positioned a yoke 85 which straddles bar 56, Figf ures 3, 5, and 7, and is secured to plate 54, the

yoke having a fiat horizontal top surface 86 which serves as a guide and support for the strip to -be tested. Desirably the yoke is provided 'with an upstanding stop 81 toward the rear of face-86 as particularly shown in Figure 5.

Plate 54 is provided on a diameter with

vertical bores

88 and 89, Figure 4, which are equally spaced from the center of plate 54, the bore 88 being in front of jaw 62 and to the left of the space S while the bore 89 is to the rear of jaw 8| and to the right of the space S. Fixed in the

bores

88 and 89 are tubular uprights 90 and 8|, these uprights having

stop collars

92 and 93 held against the top of the plate 54 by nuts 94 and 95 beneath the latter, Figure 4. Slidable in members 90 and 9| are

upright rods

96 and 91 whose lower ends are xed in plate 38 of assembly 31. Reference numeral 98 designates a cross head above tubular upright 90 and 9| having 4'set therein thimbles 89 and |00 which receive the upper ends of

uprights

96 and 91 which are secured thereto by pins |0| and |02. The thimbles have bottom flanges |03 and |04 engaged under shoulders provided in the cross head for the transmission of upward movement to the latter, the thimbles resting on the upper ends of members 98 and 9| for C' like the unit C but positioned inwardly thereof so as not to interfere. In the space between jaws ||0 and v| a yoke ||5, which is exactly like yoke 85, straddles bar |85, the 'yoke 'having a guid face Hs directly above and parallel to the face B6 of yoke 85 and having a stop ||1 aligned with stop 81.

, In Figures 1 and reference numeral ||8 designates a vpipe leading from a source-of air under presure to a rotary three-way valve H9, the lat- 'ter having av connection |20 to a fitting |2I in the head 61, a flexible hose |22 leading from the fitting |2| to a fitting |23 in the outer head of unit H4;

The stem of valve 33 hasA secured thereto an operating handle |24, Figures 1 and 2 which has an extension |25 pivoted to one end of a link |26 whose other end is pivoted to an arm |21- on the stem of valve ||9, arm |21 having the same effective length as arm |25. By swinging arm |24 a certain distance to. the right water under pressure will be admitted beneath piston 22 and air under pressure will be simultaneously admitted to the pneumatic cylinders. Further movement of. arm |24 to the right will connect pipe 32 to the outlet |28 of valve 33 while the pneumatic cylinders will be simultaneously vented to the outlet |29 of valve H9.' Breathing 'at the right end sides of the pneumatic pistons, for the prevention of dash pot eflects can be provided for in any suitable manner, for example, by aperturing the right hand cylinder heads.

For the purpose of illustration it is assumed that a strip of plywood P, Figures 3 and 7, is to apart and out of the gripping area of the jaws.l

As shownin Figure -7, jaws 6| and having been adjusted to contact'with the adjacent face of the strip and a straight edge member |38, secured to jaw III, is aligned with the vertical rear edge of jaw 8|, showing that the jaws have been uniformly adjusted. A similar straight edge displaced to engage the strip, as shownv in Figure 7,

before pressure has had time to build up substantially in the hydraulic chamber. As the water pressure builds up, piston 22vwil1 rise and bearing against 'diaphragm 40 will carry with it the crosshead and upper jaws until the tension on the-strip becomes such that the strip separates. The pressure at which the strip separates is indicated by the gauge needle and noted by the operator. 'I'he valves are now turned to their second, or exhaust position, and all of the pistons are returned, those of the pneumatic units by the springs and that of the hydraulic unit by gravity.

In Figure 3 there are shown iingers |3i and |32 projecting radially from piston 22 and assembly 31, these giving a direct visual indicationoi the relative position of the two elements.

A lubricating system for the jaws has been shown in Figure 3 and is believed to be .clear Without explanation. Elements as at |33 are oil hole plugs.

As has been previously stated, the disclosure herein is intended as illustrative and not restrictive of the invention, and variations in the form and arrangement of parts are contemplated under the claims which follow: y

We claim:

1. In apparatus for testing the tensile strength of a strip of material, two sets of 'opposed coop`-I erating jaws, one jaw of each set being reciprocable relative to its cooperating jaw, the jaws of each set being normally spaced apart to provide an opening between them greater than the thickness of the strip to be ytested and said sets.

strip when the strip is disposed in the jaw operi-J ings, valve means controlling the air pressure for` the simultaneous supply to. the pneumatically actuated devices, hydraulically actuated means for moving the said sets of jaws apart whereby to tension the clamped strip, valve means for controlling the waterpressure supply, and means for simultaneously operating the two valve means ness of the strip to be tested and said sets being being arranged so that the jaw openings are in alignment, an independent fluid pressure actuated device associated with each of said reciprocable jaws for moving each toward its cooperating jaw to clamp longitudinally spaced portions of the strip when the strip is disposed in the jaw openings, a three way valve arranged for the simultaneous supply of pressure fluid to the fluid pressure actuated devices and for the simultaneous exhaust therefrom, and means for moving 'the said sets of jaws apart whereby to tensionY the clamped strip.

2. In apparatus for testing the tensile strength of a strip of material, two sets of opposed cooperating jaws, one jaw of each set being recipro-v cable relative to its cooperating jaw, the jalws of each set being normally spaced apart to provide an opening between them greater than the thickness of the strip to b e tested and said sets being arranged so that the jaw openings are in alignment, pneumatically actuated means associated with said reciprocable jaws for moving them toward the respective cooperating jaws .to clamp longitudinallyspaced portions of the strip when the strip is disposed in the jaw openings,

` valve means for controlling the air pressure supply; hydraulically actuated means for moving the said sets of jaws apart whereby to tension` the clamped strip, valve means for controlling the water pressure supply, and means for simultaneously operating the two' Valve means for simultaneous supply.

3. In apparatus for testing the tensile strength of a strip of material, two sets of opposed cooperating jaws, one jaw of each set being reciprocable relative to its cooperating jaw, the jaws oi' each set being normally spaced apart to provide an opening between them greater than the thickness of the strip to be tested and said sets being arranged'so that the jaw openings are inalignment, an independent pneumatically actuated device associated with each of said reciprocable jaws for moving each toward its cooperating jaw to clamp longitudinally spaced .portions of the arranged so that the jaw openings are in alignment, an independentV pneumatically actuated device associated with each of said reciprocable jaws for moving each toward its cooperating jaw to clamp longitudinally spaced portions of the strip when the strip is disposed in the jaw openings, a three way valve arranged for the simulytaneous supply of air pressure to thepneumatically actuated devices and for the simultaneous exhaust therefrom, hydraulically actuated means `for moving the said sets of jaws apart whereby to tension the clamped strips a three -way valve for controlling Vthe supply of water pressure to said` hydraulically actuated means and the Yexhaust therefromand means for simultaneously operating said valves for simultaneous exhaust.

5. In apparatus for testing the tensile strength of a strip of material, a pair of` gripping devices arranged to grip longitudinally spaced portions of a strip to be tested, an independentpneumatically actuated device associated with each of said gripping devices and operable to close the latter onthe strip, hydraulically actuated means arranged to move said gripping devices apart to tension the gripped strip, a common valve for controlling the simultaneous supply of air to the pneumatically actuated devices, a valve for controlling the supply of water to said hydraulically actuated means, and a common operating means for operating said valves in unison. f

6; In apparatus for testing the tensile ystrength of a strip of material, a pair of gripping devices arranged to grip longitudinally spaced portions of a strip to be tested, an independent pneumatically actuated device associated with each of said gripping devices and operable to close the latter on the strip, hydraulically actuated means arranged to move said gripping devices apart to tension the grpped'strip, a common three-way valve for controlling the simultaneous supply of air to the pneumatically actuated devices and for controlling the simultaneous exhaust therefrom, a three-way valve for controlling the supply of water to the and for controlling the exhaust therefrom, and a common operating means for operating said valves in unison.

'7. In apparatus for testing the tensile strength of a strip of material, a base, a pair of horizontally opposed jaws on said base, means retaining said jaws against upwardrdisplacement relative to the base, one of said jaws being reciprocable hydraulically actuated means A for vertical reciprocation, said members being disposed at opposite sides of said jaw opening,` a crosshead fixed to said members above said jaws, a pair oi! horizontally opposed jaws beneath said crosshead, means retaining the second-mentioned pair of lawsv against downward displacement relative to the crosshead, said second-mentloned pair of jaws normally defining an opening of the same extent as the rst opening and aligned therewith and one thereof being reciprocable relative to the other, a cylinder and piston unit carried by the crosshead of which the piston is operatively associated with the reciprocable jaw of said second-mentioned pair, means fory supplying a pressure iluid to said lunits whereby to move each reciprocable Jaw 'toward its associated jaw to clamp longitudinally spaced portions of the strip when the strip is disposed in the Jaw openings, a common valve for controlling the supply of pressure-fluid to both of said units, and 'means for moving said upright members upwardly whereby to tension the clamped strip.

8. In apparatus for testing the tensile strength of a strip of material, a base, a pair of horizontally opposed jaws'on said base, means retaining said jaws against upward displacement relative to the base, one of said Jaws being recipro- .associated with said reciprocable jaw, a pair of upright members'supported by said base for vertical reciprocation, said 'members being disposed at opposite sides of said jawopening, a crosshead fixed to said members above said jaws, a pair of horizontally opposed jaws beneath said crosshead,

cable relative to the other and being normally spaced from said otherto provide an opening between them greater than the width of ythe strip to be tested, a cylinder and piston unit supported by said base, the piston of said unit being operatively associated with said reciprocable jaw, a pair of upright members supported by said base for vertical reciprocation, said members being pair of jaws against downward displacement relative to the crosshead; said second-mentioned pair of jaws normally deiinin'g n opening of the same `extent as the rst opening and aligned therewith and one thereof being reciprocable relative to the other, a cylinder and piston unit carried by the crosshead of which the piston is operatively associated with the reciprocable jawof said secondmentionedpain means for supplying pressure fluid to said units whereby to move each reciprocable jaw toward its associated jaw to clamp longitudinally spaced portionsl of the strip when y the strip is disposed in the jaw openings, a commeans retaining the Isecond-mentioned pair of jaws against downward displacement relative to the crosshead, said second-mentioned Ipair of Jawsnormally defining an opening of the same extent as the first opening and aligned therewith and one thereof being reciprocable relative to the other, a cylinder andpiston unit carried by the crosshead of which the piston is operatively associated with the reciprocable jaw of said secondmentioned pair, means for supplying pneumatic pressure uid to said units whereby to move each reciprocable jaw toward its associated jaw to clamp longitudinally spaced portions of the strip when the strip is disposed in the jaw openings, hydraulic pressure fluid responsive means for moving said upright members upwardly whereby to tension the clamped strip, separate valve means for the control of the two pressure iiuids, anda common operator for said valve means so that air and water under pressure can be simultaneously supplied to said units and hydraulic pressure iluid responsive means respectively.

. WALTER D. LAWSHE.

WINSTON A. GARDINER.

REFERENCES CITED rIhe following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name c Date 662,327 kVermilye Nov. 2o, 1900 1,848,468 Emery, Jr Mar. 8, 1932 2,067,626 Benninghoi Jan. 12, 1937 993,700 McKnight May 30, 1911 2,363,930 Basquin Nov. 28, 1944 2,061,369 Prendergast et al. Nov. 1 7, 1936