US1465927A - Hardness-testing device - Google Patents

Description

Aug. 28, 1923.'

' R. BAUMANN EAEDNEss TESTING DEVICE MJ A', .//7 venten" EEE;

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Patented aeg. ze, i923.

unirse stares rareur orricel.

. RICHARD BAUMANN, or STUTTGART, GERMANY,

HARDNESS-TESVING DEVICE.

Application filed 'June .21, 1921,1 Serial No. 479,413.

To all 107mm t may concern: -1 Be 1t known that I, RICHARD BAUMANN, a citizen of the German Republic, and a resident of Stuttgart, Germany, have invented 'a predetermined position and with a predetermined spring pressure so that it strikes a die and therewith forces the test ball into the material to be tested. lln order that such an instrument should beA satisfactory it is essential in the irst place that Yduring the striking movement there shall be practically no action of Jrictionall forcesand tlierhammer should becontinuously central and be always released in exactly the same manner. Secondly a predetermined equal amount of work must be done at each stroke, which on release of the hammer should be transmitted to the die, and thirdly strokes of dierent rstrength should be obtainable with one and the'same apparatus, according to the hardness and dimensions of the material to `be tested. Fourthlyit is, essential that test balls of different size maybe insertedor interchanged withk other impression producing pieces.V Finally, the spring producing the stroke should be so adjustable with re-V spect as to its length and pressure that strokes of the saine strength may be obtained.

-In accordance with this invention these results are obtained by the particular arrangements hereinafter describedfor guiding and releasing the weight. The hammer Vor weight is not externally guided and in fact is guided solely by a central pin or rod along which it slides. The compression of the spring which acts on the'hammer or weight and causes it to accelerate at the moment of release is effected by holding the hammer -body by means of three cams uniformly varranged around the weight, while compressing the spring by pressing the testing device' on the test material and the necessarily sudden release of the weight is eiected by the particular form of these camsiand of the shoulders on the .weight by meansof which said weight Vbears on the cams. As a result blows of different strengthV may ber imparted vby forming the guidesleeve of -tlie testing device with openings at diii'erent heights for thecams which raise the weight and release r yit at a predetermined position, or the weight itself is formed with shoulders to b ear on the camsV at dierent points or 'heights or otherk60 wise.

agrammatically thel openings in the guide sleeve of the device' at diilernt, heights and positions.V Fig.Y 3 isv a View of a weight formedfwith shoulders." e l f' As shown, l denotes the ball l.which is pressed onv the material to: beztestedfand which dueto the force of theY weight leaves an impression in the material the .depth of c I which impression, iotherconditions are alike, depends on the hardness of the'matef rial, and thus formsfa vmeasure, of the hard- "5 ness of the material.` This ballflismounted inthe socket 3 which is screwed into the leasing Zot' the device,iandis held by-a die 4 l mounted tliereover so Athat ittcan be intenchanged with other members.y On the innerr 8O Y wall of the casing two cams yfo'rmed with Vblade springs 6 are symmetrically arranged Y around the circumference. My vinvention is Ynot restricted by the use olif two l cams. These cams 5 may project through openings 85 7 in the casing 2 and through corresponding openingsSv or 9 on'an Vexternal guide sleeve 10 Vwhen said corresponding openings `8 or 9 pass by these openings 7. The guide sleeve vl0 thusslides on the'casing 2. In theinter- 90 mediate position ofthis' guide sleeve`A the canis are pressed inwards.'` AA pinV or rod ll is centrally mounted with respect toV sleeve l0 and it is secured' thereto. This p in or rod serves asa guide vfor the Vweight l2 which95 is otherwise free. A helical spring 13 is adjustably secured in the guide sleeve 10 l by means of ahead 14. The bottomV end l5 of the spring bears ona shoulderron the weight'l2 and by raising this weight the 100V spring is4 compressed accordingv to' the amount which the weight is raised. *The A preferred embodiment of the invention weight 12 has downwardly inclined annular shoulder 16 which on depression oi the guide sleeve contacts with the cams 5 so that when the testing device is placed on. the Ywork and the sleeve 10 depressed the weight 12 is held by these cams 5and the spring 13 compressed. l/Vhen the openings` 9 in thev guide sleeve pass the openings in the casing 2 the cams 5 pass through these openings the movement beingv assisted by their inclined portions parallel to the ders 16. rhe weight is thus suddenly rey leased and the spring 13which has been previouslycompressed to the desiredextent eX- pands downwardly and :drives the weight whose movementvis notr substantially retard'- f ed by' friction andiiimparts a blow, correvsponding. to the compression .of the spring, to

the die and to the testing ball or the member proi'fidedvinA lieu thereof. As the openings v9.are provided at'diterent lateral positions in the outer Iguide sleeved() the said sleeve can be `turned so that vone oi these'openin'gs y rmoves earlier or later into the path Vof the opening fwhich-producesstronger or weaker blows. Y Y Y After the weight has been released and the 'blow has been .struclr, the guide sleeve 10 is movedoutwardly with respect to casing 2.A

. Instead of using different openings laterally arranged in the guide sleeve 1Q as shown in Fig. 2shoulders 16 are provided shown .in 3.

atdiilierent :heights on the weight itself as I It is then possible lto obtain strolresof 'different strengthl according to the amountjby which 'thevsleeve 10 is moved out of the'casing of the testing de-Y vice. .Anfadditional advantage is secured inthatlinrorder to move the-testing device again. into striking position it is not neces- Y sary to moveY the slee-ve 10 up with the ball, it

being sulicient vto withdraw the guide sleeve 10 viromvtheY casing`2 independently Vof the position inthe space thereof. Further modyiiications may. be made so long as the arrangement for obtaining blows of different strength is retained. An internally threaded bushing 17 haviiiga shoulder is fitted into the casing 1 0 and the 'top of the spring 13 is adjustably clamped between thebushing 17 and the externally threaded head 14. LVThe rod 11 is connected tol the head 19 by the nut119. The member. 19 is kept in position bythe externally threaded cap 18.

lf have described the parts herein by means .or reference numbers but l i ish to make it Y.clear that wherever l 4,use such numerals, either in then description or in the claims,

that I do not wish toV be limitedto the de- `tails ofthe embodiments herein illustrated. The operation of my device is as follows: VThe apparatus is placed .upon the objectto be. tested, with theballl in 'contact with the surface of thesaid object. The casing`10 is then depressed. VWhen the openings 8 pass shoul- Y by the opening 7 ,they force thercams 5 inwardly against the resistance or the spring arm 6. -lence before the shoulder 16 ol the weight 12 has passed below the tops of the said cams 5, the said cams 5 have been moved so as to hold the weight 12 and pre-V vent the downward movement thereof. TheV downward movement of the casing 10 while the weight 12 is being held, causes the compression otthe spring 13. 1When the openings 9 register with the Openings 7, the spring arms 6, as well as the pressure of theinclined shoulder 16 upon the inclined top of surface oi? the cams 5, cause these cams 5 to move outwardly V'with great released. The weight 12 now-'strikes the die 1ra sharp blow so as to press the ball v1v into the surface of the object lwhich is being tested. Since the spring 13 `can be adjust-V ably held by the parts before described, any one of the. shoulders 160iI the?A weight 12 shown in Fig. 8 canQbe causedto engagev with the cams 5 soas' to provide'blows of greater or less strength.

VVVrapidity', so Vthat theyVY V,project through the openings l9 and the weight v12 is Having now particularly ydescribed the nature of my invention, vwhat I: claim as newY and desire to secure by Letters yPatent of the United States is: f f Y 1. VIn an apparatus fortesti-ng the hardness ot materials a combina-tion. of ak weight and a springl cooperating therewith, means for moving the said spring soV as ,to compress it, and means Jfor simultaneously holding Vvthe weicht so as to prevent the movement thereof yithe action of theV saidA spring, and

means adapted to automatically causeV the release lof the said weight when. compression of the spring Ais at'ai'predetermined limit. i Y

2. Inl an apparatus for testing the ihard;- ness or materials the*conibination.v of the casing 2,.a' sleeve `1Oslidable thereon, :the weightl 12 and the spring 13Av connected'. to

Vthe casing 10', and holding means located inv the casing 2 and` adapted to hold .the weight 12 while the casingylis beingV moved to compress the spring 13 and means adapted -to automaticallyr cause the .release of the the shoulder 16 adapted to beyengaged by the Y cams 5, the said casing 10 alsoA having the openings 9" therein.

4. An apparatus according to claim 3 iiiv which the spring 13 is adjustably held in the surface of vthe cams 5 being inclined to the casing 1Q. said spring arms 6.

5. An apparatus according to claim 3 in In testimony whereof I affix my signature Which the Weight 12 has a plurality of in presence of two Witnesses.4

` 5 shoulders 16. RICHARD BAUMANN 6. An apparatus according to claim 3 in Witnesses: v. which the cams 5 are mounted on spring FRIEDRICH ENNLER,

arms 6, the shoulder 16 and the adjacent EMILIE Zum.

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