US3892933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for locking and related releasing of closure devices of doors of machines, more particularly for washing machines
Assignee: Individual
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Filing: 1972-11-24
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Granted: 1975-07-01
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Expires: 1992-11-24
Abstract
Abstract An apparatus for locking and belated releasing of closure devices of doors of machines, more particularly for washing machines, wherein a latch cooperating with the door closure hook is held in locking position during the operation of the machine by a pin which releases it with a certain time delay after switching off the machine motors, so that the door can be opened only when the members of the machine subject to inertial rotation are at a complete standstill. This time delay is obtained through a fluid pump, thermostat or other suitable device, while the latch is locked during the operation by means of an electromagnet or circuit resistance coiled on the thermostat connected to the machine starting pushbutton.
Inventors
- 👤 Onofrio Rocchitelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:02
CPC Classifications
D; D06; D06F; D06F37/00; D06F37/42; B; B04; B04B; B04B7/00; B04B7/02; B04B7/06; F; F16; F16P; F16P3/00; F16P3/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
178 words
For use in controlling the locking and releasing of latching devices on access closures in machines such as washing machines and the like, internal members of which machines preferably cease movement prior to the time when such closures may be opened for internal access thereto, which latching devices include a moveable latch device for cooperative interengagement with an associated hook member, which latch is to be locked in closed position during operation of the machine by a locking pin and is to be unlocked by actuation of said locking pin at the end of the machine operation with a pre-determined time delay, apparatus comprising a locking pin actuated by a piston moveable in a chamber, means for selectively heating said chamber according to the operative condition of the machine, and a heat expansible, low melting point wax contained in said chamber, expansion of which wax will cause actuation of said locking pin to effect locking of said latch in closed position and contraction of which wax will cause actuation of said pin to effect unlocking of said latch.
Claim 2
Dependent Claim
178 words
For use in controlling the locking and releasing of latching devices on access closures in machines such as washing machines and the like, internal members of which machines preferably cease movement prior to the time when such closures may be opened for internal access thereto, which latching devices include a moveable latch device for cooperative interengagement with an associated hook member, which latch is to be locked in closed position during operation of the machine by a locking pin and is to be unlocked by actuation of said locking pin at the end of the machine operation with a pre-determined time delay, apparatus comprising a locking pin actuated by a piston moveable in a chamber, means for selectively heating said chamber according to the operative condition of the machine, and a heat expansible, low melting point wax contained in said chamber, expansion of which wax will cause actuation of said locking pin to effect locking of said latch in closed position and contraction of which wax will cause actuation of said pin to effect unlocking of said latch.
Claim 3
Dependent Claim
20 words
A device as described in claim 1 wherein said heating means comprises an electrical resistance heater which surrounds said chamber.
Claim 4
Dependent Claim
94 words
An apparatus as claimed in claim 2 wherein a pole of the electrical resistance heater is divided into two contacts, one of which is fixed and the other is movable with the piston so that the two maintain contact and complete an electrical circuit except when the piston is actuated by the wax thermostat to position the locking pin in locked position whereby the locking pin is maintained in a locked position without continuous application of electrical energy to the electrical resistance heater and without wax over-heating and excessive pressure generation within the chamber.
Claim 5
Dependent Claim
33 words
An apparatus as claimed in claim 2, wherein a pad of elastic material is interposed between the wax and the piston to act as a gasket for the wax in the melting stages.
Claim 6
Dependent Claim
23 words
An apparatus as claimed in claim 2, wherein the expansible wax comprises a mixture of waxes having a melting point below about 50*C.
Claim 7
Dependent Claim
25 words
An apparatus as claimed in claim 5, wherein the wax mixture comprises a physical mixture of 45 percent butyl behenate and 55 percent stearyl adipate.
Claim 8
Dependent Claim
65 words
An apparatus as claimed in claim 2 wherein the piston is operatively connected to the locking pin by means of a piston rod connected to the piston and slidably positioned within a hollow cylinder formed by one end of the locking pin whereby inadvertent energization of the wax thermostat under conditions of misalignment of the locking pin and latch do not result in unsafe operation.
Claim 9
Dependent Claim
54 words
A device as described in claim 7 wherein the locking end of the locking pin is selectively replaceable with locking ends of various lengths without modifying the piston rod or hollow cylinder, whereby the velocity of the piston movement may remain the same while the wax thermostat is usable for obtaining different unlocking times.
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) | 1978-06-30 | 1978-12-30 | 1979-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-30 | 1982-12-30 | 1983-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-30 | 1986-12-30 | 1987-07-01 | $7700.00 | Window Closed / Lapsed |