Patent US4022056A successfully refreshed from Google Patents.
US4022056A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hardness testing apparatus
Assignee: Individual
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Filing: 1975-12-12
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Granted: 1977-05-10
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Expires: 1995-12-12
Abstract
Abstract Hardness testing apparatus is provided having a pair of anvil elements adapted to receive and hold a test object which may then be subjected to increasing pressures by application of an increasing force to one of the anvil elements while holding the other anvil in a fixed position. The increasing force is applied through a pivotally mounted element, one end of which operatively engages the anvil and which is provided with a weight which is movable toward its other end. Drive means for moving the weight along the pivotally mounted element are provided as well as means for stopping such movement and indicating the applied force when the test object fractures. Means are also provided for reversing the direction of motion of the weight at the time of fracture of the test object and to return the weight to a position where it is in equilibrium with the anvil.
Inventors
- 👤 Lauri C. Barland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:46
CPC Classifications
G; G01; G01N; G01N3/00; G01N3/40; G01N33/00; G01N33/15
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
165 words
A hardness testing apparatus for testing the hardness of tablets by measuring the compressive force required to fracture the same comprising spaced apart upper and lower anvils, said lower anvil for applying an upward force to said tablet, said upper anvil being vertically adjustable to hold said tablet against said lower anvil and means for securing said upper anvil in fixed position to resist said compressive force when applied by said lower anvil, lever means for applying an increasing upward force to said lower anvil, said lever means comprising a pivotally mounted element in operative engagement with said lower anvil, a weight mounted on said pivotally mounted element and laterally movable relative thereto, drive means for moving said weight laterally, and display means operatively connected to said drive means for indicating the force applied to said tablet as a function of the movement of said drive means, control means for operating said drive means and means for holding said display on fracture of said tablet.
Claim 2
Dependent Claim
165 words
A hardness testing apparatus for testing the hardness of tablets by measuring the compressive force required to fracture the same comprising spaced apart upper and lower anvils, said lower anvil for applying an upward force to said tablet, said upper anvil being vertically adjustable to hold said tablet against said lower anvil and means for securing said upper anvil in fixed position to resist said compressive force when applied by said lower anvil, lever means for applying an increasing upward force to said lower anvil, said lever means comprising a pivotally mounted element in operative engagement with said lower anvil, a weight mounted on said pivotally mounted element and laterally movable relative thereto, drive means for moving said weight laterally, and display means operatively connected to said drive means for indicating the force applied to said tablet as a function of the movement of said drive means, control means for operating said drive means and means for holding said display on fracture of said tablet.
Claim 3
Dependent Claim
54 words
Apparatus of claim 1, wherein said drive means includes a threaded rotatable drive screw, a threaded yoke block operatively engaging said drive screw and positioned to operatively engage said weight, and a reversible motor operatively engaging said drive screw whereby said motor and drive screw provide lateral movement of said yoke and said weight.
Claim 4
Dependent Claim
60 words
Apparatus of claim 2, wherein said yoke block further contains a slotted portion and yoke block arms positioned to engage said weight, guide means operating in conjunction with said slotted portion for maintaining said yoke in a substantially vertical position during lateral movement thereof, said weight being free to move vertically in said yoke arms when said lever means pivots.
Claim 5
Dependent Claim
78 words
Apparatus of claim 3, further including a lower anvil housing provided with a bore to receive said lower anvil and containing an opening to receive said lever means, a journal bearing mounted in said lower anvil housing for receiving said pivotally mounted element whereby an accurate measurement of said fracture force is indicated by said display means as a result of the precise and unimpeded movement of said weight and said pivotally mounted element about said journal bearing.
Claim 6
Dependent Claim
44 words
Apparatus of claim 2, wherein said display means further includes an encoder connected to said drive screw for providing a predetermined number of pulses per revolution of said drive screw and a counter operatively connected to said encoder into which said pulses are fed.
Claim 7
Dependent Claim
25 words
Apparatus of claim 1 wherein said control means includes means for reversing said drive means whereby the direction of motion of said weight is reversed.
Claim 8
Dependent Claim
29 words
Apparatus of claim 6 wherein said control means further includes means for deactivating the drive means when the weight reaches a predetermined position in response to the reversed motion.
Claim 9
Dependent Claim
34 words
Apparatus of claim 7 wherein said control means further includes means for impressing a dynamic braking current on said drive means when the weight reaches a predetermined position in response to the reversed motion.
Claim 10
Dependent Claim
29 words
Apparatus of claim 1 wherein said control means includes means for reversing said drive means on fracture of the test object in response to movement of said lever means.
Claim 11
Dependent Claim
30 words
Apparatus of claim 9, wherein said means for holding said display on fracture of said tablet maintains said display when the direction of motion of said drive means is reversed.
Claim 12
Dependent Claim
69 words
Apparatus of claim 1, wherein said upper anvil is threaded, and wherein said means for securing said upper anvil in fixed position to resist said compressive force includes an upper anvil housing, said housing being provided with a threaded bore for receiving said threaded upper anvil, and a rotatable handle attached to said upper anvil whereby the rotation of said handle permits vertical adjustment of said threaded upper anvil.
Claim 13
Dependent Claim
114 words
Apparatus of claim 1, wherein said means for securing said upper anvil in fixed position to resist said compressive force includes a threaded set screw, an upper anvil housing provided with a bore to receive said upper anvil in sliding engagement and containing a tapped hole for receiving said threaded set screw, said upper anvil further provided with knurled circumferential surface for manually gripping said anvil and vertically moving said anvil within said bore, said anvil having an inwardly inclined flat surface whereby said threaded set screw is adjusted to engage said flat surface to hold the upper anvil in position after said anvil is adjusted to be in proper contact with said tablet.
Claim 14
Dependent Claim
29 words
Apparatus of claim 1, further including a lower anvil housing provided with a bore to receive said lower anvil and containing an opening to receive said pivotally mounted element.
Claim 15
Dependent Claim
152 words
Apparatus of claim 13, wherein said lower anvil contains a reception means for engaging said lever means, said lever means further including a journal bearing mounted in said lower anvil housing for receiving said pivotally mounted element, said pivotally mounted element having a far end and a near end with respect to said journal bearing, said near end having an enlarged surface operatively engaging said reception means of said lower anvil, said journal bearing engaging said pivotally mounted element slightly inward of said enlarged surface, said weight engaging said pivotally mounted element at a position near said journal bearing, said position of said weight being at the furthest point of its travel away from said far end, whereby said upward increasing force transmitted to said lower anvil is approximately zero at such position, the total weight of said lower anvil substantially equaling that of said weight acting through said pivotally mounted element.
Claim 16
Dependent Claim
37 words
Apparatus of claim 14, further including a counterweight attached to said lower anvil, whereby the weight of said lower anvil and said counterweight is substantially equal to that of said weight acting through said pivotally mounted element.
Claim 17
Dependent Claim
34 words
Apparatus of claim 13, further including a shield attached to said lower anvil for supporting said tablets and preventing them for entering said lower housing through said bore upon the fracture of said tablet.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-09 | 1980-11-08 | 1981-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-09 | 1984-11-08 | 1985-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-09 | 1988-11-08 | 1989-05-10 | $7700.00 | Window Closed / Lapsed |