US3785686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Door latch
Assignee: Decalock Ltd
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Filing: 1972-05-05
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Granted: 1974-01-15
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Expires: 1992-05-05
Abstract
Abstract A door latch having interchangeable handles for attachment to a suitably prepared door by a pair of interchangeable handle mounting elements. A latch bolt is also adapted for positioning in the door in engagement with cam ends of the handles so that movement at the handles results in movement of a slider in the latch bolt for opening the door. Each handle is pivotally coupled to a corresponding element by a combination of curved ribs and grooves and a resilient finger on the handle rides on a stresslimiting ramp formed in the element to bias the handle into a normal position.
Inventors
- 👤 R Armstrong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:59
CPC Classifications
E; E05; E05C; E05C1/00; E05C1/08; E05C1/12; E05C1/14; Y; Y10; Y10T; Y10T292/00; Y10T292/57
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
277 words
A door latch engaged in a door having a first opening extending from a surface of the door perpendicular to the surface, and a second opening extending from an upright edge of the door into the first opening, the axes of the openings being substantially perpendicular and the door latch comprising: a handle mounting element defining a ramp; fastener means attaching the element to the door with the element in contact with the door surface and covering an end of the first opening such that the ramp converges with the axis of the first opening; a handle having a resilient finger, the handle and the handle mounting element defining means whereby the handle is pivotally coupled to the element with a distal end of the finger in sliding contact with the ramp, the finger being stressed sufficiently to retain the handle in a normal position and being further stressed upon pivoting the handle into a deflected position, the finger end and ramp being arranged so that the finger end slides on the ramp as the handle moves between the normal and deflected positions to limit bending stresses in the finger so thaT the material of the finger is not deformed permanently; a latch bolt having a housing and a slider engaged in the housing for movement between a normal position and a withdrawn position, the latch bolt being engaged in the second opening; and the handle and latch bolt defining means operably coupling the handle to the latch bolt so that said pivotal movement of the handle towards the deflected position results in moving the latch bolt slider inwardly from said normal position to said withdrawn position.
Claim 2
Dependent Claim
277 words
A door latch engaged in a door having a first opening extending from a surface of the door perpendicular to the surface, and a second opening extending from an upright edge of the door into the first opening, the axes of the openings being substantially perpendicular and the door latch comprising: a handle mounting element defining a ramp; fastener means attaching the element to the door with the element in contact with the door surface and covering an end of the first opening such that the ramp converges with the axis of the first opening; a handle having a resilient finger, the handle and the handle mounting element defining means whereby the handle is pivotally coupled to the element with a distal end of the finger in sliding contact with the ramp, the finger being stressed sufficiently to retain the handle in a normal position and being further stressed upon pivoting the handle into a deflected position, the finger end and ramp being arranged so that the finger end slides on the ramp as the handle moves between the normal and deflected positions to limit bending stresses in the finger so thaT the material of the finger is not deformed permanently; a latch bolt having a housing and a slider engaged in the housing for movement between a normal position and a withdrawn position, the latch bolt being engaged in the second opening; and the handle and latch bolt defining means operably coupling the handle to the latch bolt so that said pivotal movement of the handle towards the deflected position results in moving the latch bolt slider inwardly from said normal position to said withdrawn position.
Claim 3
Dependent Claim
73 words
A door latch as claimed in claim 1 in which the pivotal coupling means comprises a pair of curved ribs on one of the handle and the mounting element and a complementary pair of curved grooves in the other of the handle and the element, the grooves housing respective ribs for sliding movement therein whereby the handle pivots about an axis substantially coincident with the centre of curvature of the ribs and grooves.
Claim 4
Dependent Claim
73 words
A door latch as claimed in claim 1 in which said means operably coupling the handle to the latch bolt comprises a cam fixedly coupled to the handle and a cam follower fixedly coupled to the latch bolt slider, the cam and the cam follower being in sliding contact so that in pivoting the handle from the normal to the deflected position the slider is moved from the normal to the withdrawn position.
Claim 5
Dependent Claim
27 words
A door latch as claimed in claim 1 in which said axis about which the handle pivots is substantially parallel to the axis of the second opening.
Claim 6
Dependent Claim
26 words
A door latch as claimed in claim 1 in which the handle and the element are of a polyoxymethylene sold under the trade mark DELRIN 500.
Claim 7
Dependent Claim
265 words
A door latch engaged in a door having a first opening extending perpendicularly from one surface of the door to the other surface of the door, and a second opening extending from an upright edge of the door into the first opening, the axes of the openings being substantially perpendicular and the door latch comprising: a pair of handle mounting elements; a pair of handles attached to respective handle mounting elements; fastener means attaching the elements to the door with the elements disposed one at each end of the first opening and in relatively tight engagement with respective said door surfaces; each of the elements defining one of a pair of curved ribs and a complementary pair of curved grooves, and each of the handles defining the other of the pair of ribs and the pair of grooves, the pair of grooves housing respective ones of the pair of ribs for sliding movement therein whereby the associated handle pivots about an axis substantially coincident with the centre of curvature of the ribs and grooves; a latch bolt having a housing and a slider engaged in the housing for movement between a normal position and a withdrawn position, the latch bolt being engaged in the second opening; the handles and the latch bolt defining means operably coupling the handles to the latch bolt so that said pivotal handle movement towards a handle deflected position results in moving the latch bolt slider inwardly from said normal position to said withdrawn position; and means resiliently biasing the handles and the latch bolt slider into said respective normal positions.
Claim 8
Dependent Claim
265 words
A door latch engaged in a door having a first opening extending perpendicularly from one surface of the door to the other surface of the door, and a second opening extending from an upright edge of the door into the first opening, the axes of the openings being substantially perpendicular and the door latch comprising: a pair of handle mounting elements; a pair of handles attached to respective handle mounting elements; fastener means attaching the elements to the door with the elements disposed one at each end of the first opening and in relatively tight engagement with respective said door surfaces; each of the elements defining one of a pair of curved ribs and a complementary pair of curved grooves, and each of the handles defining the other of the pair of ribs and the pair of grooves, the pair of grooves housing respective ones of the pair of ribs for sliding movement therein whereby the associated handle pivots about an axis substantially coincident with the centre of curvature of the ribs and grooves; a latch bolt having a housing and a slider engaged in the housing for movement between a normal position and a withdrawn position, the latch bolt being engaged in the second opening; the handles and the latch bolt defining means operably coupling the handles to the latch bolt so that said pivotal handle movement towards a handle deflected position results in moving the latch bolt slider inwardly from said normal position to said withdrawn position; and means resiliently biasing the handles and the latch bolt slider into said respective normal positions.
Claim 9
Dependent Claim
125 words
A door latch as claimed in claim 6 in which each of the handles has at least one resilient finger and in which each of the elements defines at least one ramp so that each of the fingers has a distal end in sliding engagement with a corresponding ramp, each of the ramps extending axially into the first opening and converging with the axis of the first opening at an angle such that on moving a handle into said deflected position the corresponding finger slides on the associated ramp and stores energy in the form of bending stresses so that on releasing the handle this energy is sufficient to cause the finger to slide on the ramp thereby returning the handle to the normal position.
Claim 10
Dependent Claim
81 words
A latch bolt as claimed in claim 6 in which said means operably coupling the hAndles to the latch bolt comprises a pair of cams fixedly coupled one to each of the handles and a cam follower fixedly coupled one to each of the slider, the cams and cam follower being in sliding contact so that in pivoting either one of the handles from the normal to the deflected position the slider is moved from the normal to the withdrawn position.
Claim 11
Dependent Claim
28 words
A door latch as claimed in claim 6 in which said axes about which the handles pivot are each substantially parallel to the axis of the second opening.
Claim 12
Dependent Claim
26 words
A door latch as claimed in claim 6 in which the handles and the elements are of a polyoxymethylene sold under the trade mark DELRIN 500.
Claim 13
Dependent Claim
247 words
A door latch engaged in a door having a first opening extending from a surface of the door perpendicular to the surface, and a second opening extending from an upright edge of the door into the first opening, the axes of the openings being substantially perpendicular and the door latch comprising: a handle mounting element; a handle attached to the handle mounting element; fastener means attaching the element to the door with the element in contact with the door surface and covering an end of the first opening; the element defining one of a pair of curved ribs and a complementary pair of curved grooves, and the handle defining the other of the pair of ribs and the pair of grooves, the pair of grooves housing respective ones of the pair of ribs for sliding movement therein whereby the handle pivots about an axis substantially coincident with the centre of curvature of the ribs and grooves; a latch bolt having a housing and a slider engaged in the housing for movement between a normal position and a withdrawn position, the latch bolt being engaged in the second opening; the handle and the latch bolt defining means operably coupling the handle to the latch bolt so that said pivotal handle movement towards a handle deflected position results in moving the latch bolt slider inwardly from said normal position to said withdrawn position; and means resiliently biasing the handle and the latch bolt slider into said respective normal positions.
Claim 14
Dependent Claim
247 words
A door latch engaged in a door having a first opening extending from a surface of the door perpendicular to the surface, and a second opening extending from an upright edge of the door into the first opening, the axes of the openings being substantially perpendicular and the door latch comprising: a handle mounting element; a handle attached to the handle mounting element; fastener means attaching the element to the door with the element in contact with the door surface and covering an end of the first opening; the element defining one of a pair of curved ribs and a complementary pair of curved grooves, and the handle defining the other of the pair of ribs and the pair of grooves, the pair of grooves housing respective ones of the pair of ribs for sliding movement therein whereby the handle pivots about an axis substantially coincident with the centre of curvature of the ribs and grooves; a latch bolt having a housing and a slider engaged in the housing for movement between a normal position and a withdrawn position, the latch bolt being engaged in the second opening; the handle and the latch bolt defining means operably coupling the handle to the latch bolt so that said pivotal handle movement towards a handle deflected position results in moving the latch bolt slider inwardly from said normal position to said withdrawn position; and means resiliently biasing the handle and the latch bolt slider into said respective normal positions.
Claim 15
Dependent Claim
114 words
A door latch as claimed in claim 11 in which the handle has at least one resilient finger and in which the element defines at least one ramp so that the finger has a distal end in sliding engagement with the ramp, the ramp extending axially into the first opening and converging with the axis of the first opening at an angle such that on moving the handle into said deflected position the finger slides on the ramp and stores energy in the form of bending stresses so that on releasing the handle this energy is sufficient to cause the finger to slide on the ramp thereby returning the handle to the normal position.
Claim 16
Dependent Claim
72 words
A latch bolt as claimed in claim 11 in which said means operably coupling the handle to the latch bolt comprises a cam fixedly coupled to the handle and a cam follower fixedly coupled to the latch bolt slider, the cam and cam follower being in sliding contact so that in pivoting the handle from the normal to the deflected position the slider is moved from the normal to the withdrawn position.
Claim 17
Dependent Claim
27 words
A door latch as claimed in claim 11 in which the axis about which the handle pivots is substantially parallel to the axis of the second opening.
Claim 18
Dependent Claim
26 words
A door latch as claimed in claim 11 in which the handle and the element are of a polyoxymethylene sold under the trade mark DELRIN 500.
Claim 19
Dependent Claim
228 words
In a door latch of the type having at least one handle and associated handle mounting member by which the handle is pivotally mounted on a suitably prepared door, and a latch bolt operably coupled to the handle whereby pivotal handle movement from a normal position to a deflected position results in moving a slider in the latch bolt from a normal position to a withdrawn position, the improvement in which the handle and handle mounting member define respective pairs of curved grooves and complementary curved ribs housed in respective said grooves foR sliding movement therein as the handle moves between said normal and said deflected positions so that the handle pivots about an axis substantially coincident with the centre of curvature of the ribs and grooves, and in which the handle mounting element has a ramp, and the handle has a resilient finger which has an end in sliding contact with the ramp, the finger being stressed sufficiently after assembly on the element to retain the handle in a normal position and being further stressed upon pivoting the handle into the deflected position, the finger end and ramp being arranged so that the finger end slides on the ramp as the handle moves between the normal and deflected positions to limit bending stresses in the finger so that the material of the finger is not deformed permanently.
Claim 20
Dependent Claim
228 words
In a door latch of the type having at least one handle and associated handle mounting member by which the handle is pivotally mounted on a suitably prepared door, and a latch bolt operably coupled to the handle whereby pivotal handle movement from a normal position to a deflected position results in moving a slider in the latch bolt from a normal position to a withdrawn position, the improvement in which the handle and handle mounting member define respective pairs of curved grooves and complementary curved ribs housed in respective said grooves foR sliding movement therein as the handle moves between said normal and said deflected positions so that the handle pivots about an axis substantially coincident with the centre of curvature of the ribs and grooves, and in which the handle mounting element has a ramp, and the handle has a resilient finger which has an end in sliding contact with the ramp, the finger being stressed sufficiently after assembly on the element to retain the handle in a normal position and being further stressed upon pivoting the handle into the deflected position, the finger end and ramp being arranged so that the finger end slides on the ramp as the handle moves between the normal and deflected positions to limit bending stresses in the finger so that the material of the finger is not deformed permanently.
Claim 21
Dependent Claim
21 words
Apparatus as claimed in claim 16 in which the ramp lies substantially in a plane parallel to said axis of rotation.
Claim 22
Dependent Claim
24 words
Apparatus as claimed in claim 16 in which the handle and the element are of a polyoxymethylene sold under the trade mark DELRIN 500.
References Cited (Backward Citations)
US2383574A
Cited
US3655230A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |