Patent US3905150A successfully refreshed from Google Patents.
US3905150A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blocks having sockets and projections with interference fit
Assignee: ES Perry Ltd
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Filing: 1973-08-16
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Granted: 1975-09-16
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Expires: 1993-08-16
Abstract
Abstract The invention relates to a building brick for use as an educational aid, a display device or in a constructional kit for children. The brick is in the form of a solid cube having one place face, a spigot or projection of rectangular cross-section on another face, the remaining faces each incorporating a socket to accept the projection or spigot of another similar brick, the projection or spigot and socket being so shaped that an interference fit is formed when two similar bricks are joined. By making the brick of unit dimension and unit weight it can be used in constructions of bricks, inter alia, to teach the concept of weight, length, volume and so on. It is made by a process comprising injection moulding the blocks from a stiffly resilient material in a die having substantially minimum draft necessary to facilitate withdrawal, maintaining the die at a temperature below 40*F, ejecting the block from the mould when the block has cooled sufficiently to form a rigid skin and further cooling the ejected block in a bath of cold water.
Inventors
- 👤 Alan William Dawn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:49
CPC Classifications
A; A63; A63H; A63H33/00; A63H33/04; A63H33/06; A63H33/08; A63H33/088; Y; Y10; Y10S; Y10S273/00; Y10S273/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
287 words
An educational aid for teaching mathematic and scientific concepts involving weights and measures, said aid comprising a plurality of solid cubes interconnected together to define an assembled, structurally stable educational aid of desired shaped for teaching a selected scientific concept, each of said cubes having six faces and having edges of unit length, and being constructed of an injection molded, stiffly resilient plastic, a single solid unitary projection projecting centrally of one of said faces of each cube, one of said faces being completely planar on each cube, a single socket located centrally in each of the remaining cube faces, each socket including a bottom portion and an outer opening portion and being shaped and dimensioned to receive the projection of an adjacent cube, the faces of each adjacent interconnected cube being in face to face relationship, an interference fit being defined by a socket of one cube receiving a projection of an adjacent interconnected cube, said interference fit including said bottom portion of said socket being expanded relative to said outer opening portion, each said projection interconnected with another cube catching behind edges defining said opening portion of a socket of an adjacent interconnected cube for providing an interlocking plurality of said cubes which cooperate to define a structurally stable assembly of desired size, shape and weight, said projections and said sockets being square in shape and the upright edges of each projection and the upright corners of each socket having a curvature, the radius of curvature on said projection curvature being greater than the radius of curvature of said corners, said curvatures defining air passage means for the escape of air displaced from the socket by the insertion of a projection of another cube thereinto.
Claim 2
Dependent Claim
287 words
An educational aid for teaching mathematic and scientific concepts involving weights and measures, said aid comprising a plurality of solid cubes interconnected together to define an assembled, structurally stable educational aid of desired shaped for teaching a selected scientific concept, each of said cubes having six faces and having edges of unit length, and being constructed of an injection molded, stiffly resilient plastic, a single solid unitary projection projecting centrally of one of said faces of each cube, one of said faces being completely planar on each cube, a single socket located centrally in each of the remaining cube faces, each socket including a bottom portion and an outer opening portion and being shaped and dimensioned to receive the projection of an adjacent cube, the faces of each adjacent interconnected cube being in face to face relationship, an interference fit being defined by a socket of one cube receiving a projection of an adjacent interconnected cube, said interference fit including said bottom portion of said socket being expanded relative to said outer opening portion, each said projection interconnected with another cube catching behind edges defining said opening portion of a socket of an adjacent interconnected cube for providing an interlocking plurality of said cubes which cooperate to define a structurally stable assembly of desired size, shape and weight, said projections and said sockets being square in shape and the upright edges of each projection and the upright corners of each socket having a curvature, the radius of curvature on said projection curvature being greater than the radius of curvature of said corners, said curvatures defining air passage means for the escape of air displaced from the socket by the insertion of a projection of another cube thereinto.
Claim 3
Dependent Claim
16 words
The article of claim 1 wherein both said projection and said socket are square in cross-section.
Claim 4
Dependent Claim
16 words
The article of claim 1 wherein each of said cubes is made of acrylonitrile butadiene styrene.
Claim 5
Dependent Claim
16 words
The article of claim 3 wherein each of said edges of said cubes is one centimeter.
Claim 6
Dependent Claim
23 words
The article of claim 1 wherein said sockets and projections are relatively small in size as compared to the size of said cubes.
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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |