Hardness tester

Claim 2

A hardness tester comprising a stand having upper and lower jaw members, a test specimen support mounted on said lower jaw for vertical movement, a test spindle mounted in said upper jaw in alignment with said support, a loading beam mounted on said stand above said spindle to pivot about a horizontal axis, main loading means mounted on said stand above one end of said beam, and normally disconnected from said one end of said beam but connectable thereto, a separate pivot point on said beam at one side of said axis between said axis and said one end of said beam for engaging the upper end of said spindle to pivot said beam on said spindle, said pivot point being much closer to the horizontal axis of said beam than to said one end, whereby the weight of the beam portion between said one end and said pivot point is greater than the weight of the beam portion between said pivot point and said horizontal axis, means for adjusting said support upwardly to move a test specimen against the lower end of said spindle to urge said spindle and said one end of said beam upwardly, whereby said beam preloads said test specimen by resisting the upward movement of said spindle, and spaced signal generating means mounted on said stand and operative, when said one end of said beam has been pivoted upwardly a first predetermined distance toward said main loading means, to produce a first signal, and operative to produce a second signal, when said one end has pivoted upwardly a predetermined distance beyond said first distance to indicate that the test should be discontinued, and means operable after the production of said first signal to connect said main loading means to said beam, and means operative after the production of said second signal automatically to prevent operation of said connecting means.

Claim 3

A hardness tester comprising a stand having upper and lower jaw members, a test specimen support mounted on said lower jaw for vertical movement, a test spindle mounted in said upper jaw in alignment with said support, a loading beam mounted on said stand above said spindle to pivot about a hoRizontal axis, main loading means mounted on said stand above one end of said beam, and normally disconnected from said one end of said beam but connectable thereto, a separate pivot point on said beam at one side of said axis between said axis and said one end of said beam for engaging the upper end of said spindle to pivot said beam on said spindle, said pivot point being much closer to the horizontal axis of said beam than to said one end, whereby the weight of the beam portion between said one end and said pivot point is greater than the weight of the beam portion between said pivot point and said horizontal axis, means for adjusting said support upwardly to move a test specimen against the lower end of said spindle to urge said spindle and said one end of said beam upwardly, whereby said beam preloads said test specimen by resisting the upward movement of said spindle, and spaced signal generating means mounted on said stand and operative, when said one end of said beam has been pivoted upwardly a first predetermined distance toward said main loading means, to produce a first signal, and operative to produce a second signal, when said one end has pivoted upwardly a predetermined distance beyond said first distance to indicate that the test should be discontinued, hardness indicator means connected to said beam and movable thereby to a zero position, when said one end of said beam has been pivoted upwardly at least said first predetermined distance, said one end of said beam being engageable with said main loading means when said one end has been pivoted upwardly said predetermined distance beyond said first distance, whereby said second signal is operative to indicate excess upward pivotal movement of said one end of said beam. said signal generating means comprising a pair of switches mounted on said stand, and a pair of spaced actuators on said beam for pivotal movement therewith, one of said actuators being operative to actuate one of said switches, when said one end of said beam has been pivoted upwardly said first distance, and the other of said actuators being operative to actuate the other of said switches when said one end of said beam has engaged said main loading means.

Claim 4

A hardness tester comprising a stand having upper and lower jaw members, a test specimen support mounted on said lower jaw for vertical movement, a test spindle mounted in said upper jaw in alignment with said support, a loading beam mounted on said stand above said spindle to pivot about a hoRizontal axis, main loading means mounted on said stand above one end of said beam, and normally disconnected from said one end of said beam but connectable thereto, a separate pivot point on said beam at one side of said axis between said axis and said one end of said beam for engaging the upper end of said spindle to pivot said beam on said spindle, said pivot point being much closer to the horizontal axis of said beam than to said one end, whereby the weight of the beam portion between said one end and said pivot point is greater than the weight of the beam portion between said pivot point and said horizontal axis, means for adjusting said support upwardly to move a test specimen against the lower end of said spindle to urge said spindle and said one end of said beam upwardly, whereby said beam preloads said test specimen by resisting the upward movement of said spindle, and spaced signal generating means mounted on said stand and operative, when said one end of said beam has been pivoted upwardly a first predetermined distance toward said main loading means, to produce a first signal, and operative to produce a second signal, when said one end has pivoted upwardly a predetermined distance beyond said first distance to indicate that the test should be discontinued, hardness indicator means connected to said beam and movable thereby to a zero position, when said one end of said beam has been pivoted upwardly at least said first predetermined distance, said one end of said beam being engageable with said main loading means when said one end has been pivoted upwardly said predetermined distance beyond said first distance, whereby said second signal is operative to indicate excess upward pivotal movement of said one end of said beam. said signal generating means comprising a pair of switches mounted on said stand, and a pair of spaced actuators on said beam for pivotal movement therewith, one of said actuators being operative to actuate one of said switches, when said one end of said beam has been pivoted upwardly said first distance, and the other of said actuators being operative to actuate the other of said switches when said one end of said beam has engaged said main loading means.

Claim 5

A hardness tester as defined in claim 2, including electrically operated means connected in circuit with said switches and operable when said one switch only is actuated to connect said main load means to said beam, and operative when both said switches are actuated to prevent operation of said connecting means.

Claim 6

A hardness tester as defined in claim 3, wherein said main loading means comprises a weighted member, said connecting means comprises a reversible electric motor connected to said weighted member normally to hold said weighted member in spaced relation to said beam, and said switches are connected in circuit with said motor, and having cycling means operable, when said one switch only is actuated momentarily to energize said motor thereby temporarily to connect said weighted member to said one end of said beam to test the hardness of said specimen.

Claim 7

A hardness tester as defined in claim 4, including a third switch movable manually to first and second positions, selectively, means operative, when said third switch is in said first position, to prevent energization of said motor, when said other switch is actuated, and means operative, when said third switch is in said second position, automatically to actuate said cycling means when said one switch is actuated, and to interrupt said cycling means, when said other switch is actuated.