US3760635A - Durometer - Google Patents

Durometer Download PDF

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Publication number
US3760635A
US3760635A US00192498A US3760635DA US3760635A US 3760635 A US3760635 A US 3760635A US 00192498 A US00192498 A US 00192498A US 3760635D A US3760635D A US 3760635DA US 3760635 A US3760635 A US 3760635A
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United States
Prior art keywords
durometer
shearing member
shearing
casing
bore
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US00192498A
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English (en)
Inventor
A Ernst
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Individual
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Individual
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Publication date
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Publication of US3760635A publication Critical patent/US3760635A/en
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/40Investigating hardness or rebound hardness
    • G01N3/48Investigating hardness or rebound hardness by performing impressions under impulsive load by indentors, e.g. falling ball

Definitions

  • This invention relates to durometers for measuring the hardness of materials and a method for using such durometers.
  • durometers in which an external member, to which an uncontrolled external force is applied, is connected to a stern supporting a penetrating tip by an element which breaks when a predetermined force is applied.
  • the breaking element was a wire.
  • This durometer has disadvantages preventing accurate measurements of the hardness.
  • One disadvantage is that the wires, intended to break during the operation of the durometer, are usually cut from a continuously formed wire and their shear properties are seldom constant and are often found to be well outside required tolerance limits at various locations along the wire length.
  • the penetrating tip When the control bar in such a durometer is broken, the penetrating tip initially moves with a speed which is dependent upon the speed with which the external member moves immediately after shearing.
  • the depth of the impression made in the material whose hardness is to be measured therefore varies significantly if the penetrating tip, and any support member in which the penetrating tip is mounted, has a relatively large mass. It hasbeen customary in prior durometers for the penetrating tip to comprise a hardened steel ball or a diamond point mounted in a solid support member.
  • the present invention provides a durometer comprising a penetrating tip, and a shearing member intended in operation to apply a force to the penetrating tip via a control bar which is dimensioned to shear when a predetermined force is applied to it by the shearing member, in which the penetrating tip is one end of a pin whose other end abuts the control bar, and in which the durometer is provided with damping means serving in operation to absorb kinetic energy of the shearing member after shearing of the control bar.
  • the invention further provides a method of testing the hardness of a material by impressing a penetrating tip into a surface of the material to be tested, the impressing force being dependent upon the force required to shear an accurately dimensioned control bar and being transmitted to the penetrating tip by a shearing member via the control bar until the control bar shears, and by measuring the resulting impression in the material, in which method the impressing force is further transmitted by a pin, one end of which is the penetrat-- ing tip and the other end of which abuts the control bar, and in which method the movement of the shearing member is damped after the control bar has been shared.
  • FIG. 1 shows a sectional elevational view of a first embodiment of a durometer according to the present invention
  • FIG. 2 shows a similar view of a second embodiment of a durometer according to the-present invention
  • FIG. 3 shows a similar view of a third embodiment of a durometer according to the invention.
  • I FIG. 4 shows a similar view .of a fourth'embodiment of a durometer according to the-present invention.
  • a durometer comprises a susbstantially cylindrical casing 1, of. which the upper end 2 is flared as shown.
  • a cylindrical shearing member 3 isdisposed inside the casing l, the lower portion of shearing member 3 fitting snugly inside the lower portion of, the casing 1.
  • the shearing member 3 is provided with a transverse hole in its lower portion, the hole extending completely through the shearing member 3.
  • the shearing member 3 also has an axial hole in its lower portion which hole extends below the control bar 4 to the lower end of shearing member 3 and also above the control bar4.
  • a pin 5 is provided in the axial hole, the upper end of the pin 5 abutting the control bar 4 and the lower end of the pin 5 constituting a penetrating tip 6.
  • the pin 5 is frictionally held in position in the axial hole in the shearing member3 by means of a ball 7 urged against the pin by a spring 8.
  • control bar 4 will shear and only the accurately known force necessary to shear the control bar 4 will be applied to pin 5 and to penetrating tip 6.
  • the durometer In use, the durometer is placed in a surface on a material to be tested so that the bottom end of the casing l and the penetrating tip 6 contact the surface.
  • the penetrating tip 6 makes an impression in the surface due to the controlled force applied to the penetrating tip 6, and the depth of the impression depends on the hardness of the material.
  • the pin 5 may be made of small size and therefore low mass so that the inertia of the pin 5 will not significantly affect the depth of the impression in the surface of the material to be tested. Thus, an impression is formed which is substantially independent of the magnitude of the impact force applied to the head 9.
  • the shearing member 3 is further provided, as shown in FIG. 1, with a flared collar section 10.
  • a flared collar section 10 Preferably, the surface of the flared section and the inside surface of the flared section 2 of the casing 1 are substantially parallel.
  • the casing 1 does not have a flared section and the shearing member 3 does not have a flared collar.
  • the damping means are constituted by a resilient annular member 12 fixed onto the lower face of the annular shoulder 11 of the shearing member 3. In operation, damping is effected when the resilient member 12 strikes the upper face 13 of the casing l.
  • FIG. 3 is similar to the embodiment of FIG. 2, except that in FIG. 3 the annular resilient member 12 is dispensed with. Instead, the durometer is provided with an annular resilient member 14 on the bottom of the casing 1.
  • the casing 1 is not provided and damping is effected by an annular resilient member 15 on the lower end of the shearing member 3.
  • the stroke of the shearing member 3 is limited by the annular resilient member 15 striking the surface of the material to be tested.
  • a durometer comprising an elongated shearing member provided in one end portion thereof with a first bore extending in longitudinal direction of the elongation of said shearing member and a second bore extending transverse to and intersecting said first bore; a control bar dimensioned to shear upon application of a predetermined force located in said second bore; a pin slidably arranged in said first bore and abutting with one end against said control bar and projecting with the other end, which constitutes a penetrating tip for making an impression in a material whose hardness has to be measured, beyond one end of said shearing member; and damping means located outside said first bore and serving in operation to absorb kinetic energy of said shearing member.
  • said damping means comprises a resilient annular member applied to said one end of said shearing member.

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  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
  • Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
US00192498A 1970-11-24 1971-10-26 Durometer Expired - Lifetime US3760635A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT3211270 1970-11-24

Publications (1)

Publication Number Publication Date
US3760635A true US3760635A (en) 1973-09-25

Family

ID=11234915

Family Applications (1)

Application Number Title Priority Date Filing Date
US00192498A Expired - Lifetime US3760635A (en) 1970-11-24 1971-10-26 Durometer

Country Status (7)

Country Link
US (1) US3760635A (OSRAM)
JP (1) JPS543637B1 (OSRAM)
CH (1) CH532247A (OSRAM)
DE (1) DE2157466C3 (OSRAM)
ES (1) ES173168Y (OSRAM)
FR (1) FR2115805A5 (OSRAM)
GB (1) GB1333446A (OSRAM)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116026714A (zh) * 2023-03-28 2023-04-28 中山大学 一种水平孔岩石硬度测量装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US12266856B2 (en) 2021-07-12 2025-04-01 Samsung Electronics Co., Ltd. Electronic device including antenna

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE341512C (OSRAM) *
US1071430A (en) * 1913-03-21 1913-08-26 William Herbert Keen Apparatus for testing the hardness of metals.
US1348897A (en) * 1919-07-28 1920-08-10 Ringland Albert Portable brinnell hardness-tester
US2094584A (en) * 1936-07-27 1937-10-05 Ormond L Cox Limited strain wrench
US2446537A (en) * 1944-11-16 1948-08-10 Clarence N Hickman Thrust gauge
DE897628C (de) * 1951-07-29 1953-11-23 Rudolf Dr-Ing Boeklen Schlaghaertepruefer mit Vergleichstab
US3213680A (en) * 1963-03-15 1965-10-26 Du Pont Load cell protector

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE341512C (OSRAM) *
US1071430A (en) * 1913-03-21 1913-08-26 William Herbert Keen Apparatus for testing the hardness of metals.
US1348897A (en) * 1919-07-28 1920-08-10 Ringland Albert Portable brinnell hardness-tester
US2094584A (en) * 1936-07-27 1937-10-05 Ormond L Cox Limited strain wrench
US2446537A (en) * 1944-11-16 1948-08-10 Clarence N Hickman Thrust gauge
DE897628C (de) * 1951-07-29 1953-11-23 Rudolf Dr-Ing Boeklen Schlaghaertepruefer mit Vergleichstab
US3213680A (en) * 1963-03-15 1965-10-26 Du Pont Load cell protector

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116026714A (zh) * 2023-03-28 2023-04-28 中山大学 一种水平孔岩石硬度测量装置
CN116026714B (zh) * 2023-03-28 2023-06-23 中山大学 一种水平孔岩石硬度测量装置

Also Published As

Publication number Publication date
ES173168U (es) 1972-03-01
DE2157466B2 (de) 1980-05-08
DE2157466C3 (de) 1981-01-22
GB1333446A (en) 1973-10-10
FR2115805A5 (OSRAM) 1972-07-07
JPS543637B1 (OSRAM) 1979-02-24
ES173168Y (es) 1972-09-01
CH532247A (it) 1972-12-31
DE2157466A1 (de) 1972-06-15

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