US1702603A - Concrete-testing apparatus - Google Patents

Description

Feb. 19, 1929.-

O. H. HANSARD ET AL CONCRETE TESTING APPARATUS Filed Sept. 1927 Patented Feb. 19, 1929.

UNITED STATES ORREN HARDIN HA'NSABDAND DONALD, DAVID MCGUIRE,

= a I TENNESSEE.

OF NASHVILLE,

CONCRETE-TESTING APPARATUS.

- Application filed September 1, 1927. Serial No. 216,846}

This invention relates to machines for testing concrete and the present application pertains to a second species of the genus describedand claimed more broadly in our'co- I pending application, Serial No. 216,845, filed Sept. 1, 1927. The objects of the invention include the provision of improved apparatus,

a base 3 which may be provided with wheelsv 20. (not shown) whereby it may be readily trans- I ported. A platform 4 mounted upon. legs 5 at one end of the base, is provided at one end with a transverse semi-cylindrical block 6" and at its other end witha transverse triangubeam of concrete 8 is supported with its free end extending a measured distance beyond the knife edge of the member 7 preferably fastened upon its supports by a bar -9, mounting a semi-cylindrical transverse member 10 on its lower surface, which is secured to a bar 11 passing under the platform by tie bolts12. Bearing blocks 13, 14 and 15 may be interposed between the member 6, 7, and 10 respectively, and the concrete beam to serve as cushions, and these bearing blocks are preferably provided with longitudinal recesses to receive said member.

A testing lever arm, comprising a V-shaped frame consisting of metal I beam 16 bolted together at the apex of the frame and spaced at their inner ends by a transverse strut 17 is mounted above the projecting position of the concrete beamin such manner that depression of the outer end of the frame will exert a considerable pressure upon the inner end of the beam 8. For this purpose, the frame is supported, intermediate its ends upon the beam end by means of a transverse, triangular shaped bar 18 which is attached to a plate apparatus with a specimen block of concrete f lar-shaped member 7 011 which the block or The beam. is

19 fixed to the under side of the frame and which engages in the recess of a bearing block 20 traversing the top of the beam adjacent its inner end. The frame is fulcrumed near its inner end and approximately above the apex of the member 7 by a cross bar 21 mounted on brackets 22 fixed to the base 3 and provided on its underside with a bearing block 23 which engages a semi-cylindrical transverse in ember 24 of a plate 25, attached to the top of the frame. The two point support thus holds the lever arm substantially in horizontal position until a downward force isapplied at its outer end. A

At said end of the lever a rack 26 boltedbetween the arm endssupportstheupperloop 27 of the spring of a dynamometer 38 of usual construction and operation. The dynamometer hangs in a vertical plane from the rack 26v and its lowerspring loop 28 is attached to a cable 29 by a book 30. The cable may be wound on a shaft or drum 31 in bearing blocks "32fixed to the base 3, by means of a crank handle 33 operating-through suitable gearing.

Cross bars 34 and 35 supported upon brackets 36 and 37, respectively, may be arranged beneath the frame to catch the lever arm when the concrete beam has been broken in the manner now to be described.

Vhen the apparatus has been set up as thus described, the crank 33 is operated to wind up the cable, thus causing a downward pull upon the outer end of the lever arm through the dynamometer 38, depressing the lever and initiating a downward pressure upon the end of the concrete beam at the bar 18. When the breaking point is, reached the concrete beam will fracture transversely above the herein described, the computation is greatly simplified, for the required weights and dimensions may be maintained constant for repeated tests, so that the only variable factor piece of concrete upon said platform with,

one end of the test piece projecting beyond the edge of the platform, a leverextending over the projecting portion of the test piece and having its free outer end extending longitudin ally of the test piece and distant from the end thereof, a portion of said lever engaging the upper side of the test piece near the end of said projecting portion, means independent of the test pieceengaging the top of the lever adjacent its inner end to prevent movement thereof away from thetest piece, means for operating the free end of the lever to break the testpiece and a measuring'instrument associated with said last named meansfor indicating the amount of force re-' quired to breakthe test piece.

2. Apparatus for testing concrete comprising a platform, means for securing a test piece of concrete upon said platform with one end of the test piece projecting beyondthe edge of the platform, a'fixed bracket extending above said platform and having'a cross bar disposed above the test piece, a lever extending over the projecting portion of the test piece, the inner end of the lever passing under said cross bar'and engaging the bar whereby" movement of said lever end'awayifrom the test piece is prevented and the free'outerrend of the lever ext-ending outwardly from the end of the'test piece and longitudinally thereof, said lever having abet-tom cross member engaging the'upper side of the test piece near the end of said projective portion, means for operating the free end of the lever to break the test piece, and a measuring instrument associated with said last named means adapted to indicate the amount of force required to break the test piece.

3. Apparatus for testing concrete compris= ing a horizontal platform, means for securing a test piece of concrete upon said platform with one end of the test piece projecting beyond the edge of the platform, an upright bracket extending above said platform, a cross bar fixed to said bracket transversely of the test piece and approximately in the plane of the said edge of the platform, a horizontal lever extending longitudinally of the test piece and having its: inner end extending over the test piece and under said cross bar, said bar having a bottom transverse member intermediate its ends engaging the upper side of the test piece near the end of its projecting portion and having a top transverse member near its inner end engaging said cross bar, so that the lever is supported in horizontal position by said engagements,

means connected with the free end of the lever for depressing the lever to break the test piece, and a measuring instrument associated with said depressing means adapted to indicate the amount of force required to break. the test piece.

4. Apparatus for testing concrete-comprising a horizontal platform having a pair of upstanding supports for a test piece of concrete, one: of said supports being disposed above one edge of the table and having a sharp upper edge parallel with said platform edge, means for securing the test piece upon said supports with one end of the test piece projecting beyond the said sharp-edged sup'-; port, an upright bracket extending above said platform, a crossbar fixed to said bracket transversely of the test pieceand approximately in the plane of the said edge of the platform, a horizontal lever extending longi-- tudinally of the test piece and having its inner end extending over the test piece and under said cross bar, said bar having a bot tom transverse member intermediate its ends engaging. the upper side of the testpiece near the end of its projecting portion and havingv a top transverse member near its-inner end engaging said cross bar, sothat the lever is supported in horizontal position by said-engagements, means connected with the free end of the lever for depressing the: lever to break the test piece, and a measuring instru ment' associated with saiddepressing means adapted to indicate theamountofforce required to break the test piece.

5 Apparatus for testing concretecomprising a-horizontal platform having a pair of up-' standingsupports for a test piece of concrete, one of said supports being disposed above one edge of the table and having a shar upper, edge parallel with saidplatform e ge, the other support comprising a semi-spherical bearing with a plate resting on its upper surface as a supportfor a'testpiece'of concrete; means: for securing the test piece upon said support including a third support comprisingya semicylindrical unit resting on a. plate, one end of the test piece projecting beyond the sharp edged support, an upright bracket extending above said platform, a crossbar fixed to saidbracket transversely of the test piece and approximately in the plane ofthe said edge of the platform, a. semi-cylindrical bearing and a plate attached to the underside of said crossbar, a horizontallever extending longitudinally of the test piece and having its inner end extending over the test piece and under said crossbar so that said inner end bears against said crossbar bearing a transverse member fastened to said lever-intermediate, its ends engaging the upper side of the test piece near the end of its projecting portion and having a top transverse member near its inner end engaging said crossbar adopted to indicate the amount of force rein the manner above set out so that'the lever quired to break the test piece.

is supported in horizontal position by said lntestimony whereof weafiix our signa- 10 engagements, means connected with the free tures.

end of the lever for depressing the lever to break the test piece and a measuring instru- ORREN HARDIN HANSARD.

ment associated With said depressing means DONALD DAVID MCGUIRE.

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