Patent US3945660A successfully refreshed from Google Patents.
US3945660A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Structure for folding shopping carts, laundry carts and the like
Assignee: Individual
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Filing: 1975-05-16
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Granted: 1976-03-23
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Expires: 1995-05-16
Abstract
Abstract A folding shopping cart, laundry cart or the like in which a generally box-shaped fabric sack serves as an essential structural integer for holding two rigid generally horizontal upper side members of the cart in parallel relationship a given distance apart against forces developed upon unfolding the cart which would otherwise spread the upper side members further apart. The back and the bottom of the cart have respective cross frames of centrally pivoted rigid members, while the front of the cart has a parallel spaced pair of rigid vertical side members. The cart is locked into its unfolded condition by a knuckle-jointed cross brace between the lower ends of back cross frame. The rigid members of the cart are so interconnected that the cart folds into a stick-like bundle which includes wheels provided at the four corners of the bottom cross frame and a pair of rigid handle members articulated to the rear ends of the upper side members.
Inventors
- 👤 Michel Zalewski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:19
CPC Classifications
B; B62; B62B; B62B3/00; B62B3/10; B62B3/02; B62B3/027; B62B2202/00; B62B2202/66; B62B2205/00; B62B2205/06; B62B5/00; B62B5/06; B62B5/067; B62B9/00; B62B9/20; B62B9/206
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
310 words
In a folding cart assembly having a back cross frame of centrally pivoted rigid members, a bottom cross frame of centrally pivoted rigid members, pivotal connection means attaching one of each of the bottom frame members to one of each of the back frame members at each of two corners of said cross frames to permit the members of each cross frame to pivot with respect to each other and to permit said cross frames to pivot with respect to each other, and releasable means for holding the members of at least one of the cross frames in an extended position when the assembly is unfolded, the improvement comprising: a. a first pair of members pivotally attached at first ends thereof to the bottom cross frame near the other two corners of the bottom cross frame, respectively; b. a second pair of members pivotally attached at first ends thereof to the back cross frame near the other two corners of the back cross frame, respectively; c. two 270° knuckle joints, each connecting a second end of one of said first pair of members to a second end of one of said second pair of members, for holding the first pair of members in a vertical position and the second pair of members in a generally horizontal position when the assembly is unfolded and said at least one of the cross frames is held in an extended position by said releasable means; and, d. a generally box-shaped fabric sack open at the top thereof and fixedly attached along its opposed upper side edges to said second pair of members for holding said second pair of members in parallel relationship with predetermined spacing therebetween against forces urging them apart which are developed in the assembly when it is unfolded with said at least one of the cross frames in said extended position.
Claim 2
Dependent Claim
310 words
In a folding cart assembly having a back cross frame of centrally pivoted rigid members, a bottom cross frame of centrally pivoted rigid members, pivotal connection means attaching one of each of the bottom frame members to one of each of the back frame members at each of two corners of said cross frames to permit the members of each cross frame to pivot with respect to each other and to permit said cross frames to pivot with respect to each other, and releasable means for holding the members of at least one of the cross frames in an extended position when the assembly is unfolded, the improvement comprising: a. a first pair of members pivotally attached at first ends thereof to the bottom cross frame near the other two corners of the bottom cross frame, respectively; b. a second pair of members pivotally attached at first ends thereof to the back cross frame near the other two corners of the back cross frame, respectively; c. two 270° knuckle joints, each connecting a second end of one of said first pair of members to a second end of one of said second pair of members, for holding the first pair of members in a vertical position and the second pair of members in a generally horizontal position when the assembly is unfolded and said at least one of the cross frames is held in an extended position by said releasable means; and, d. a generally box-shaped fabric sack open at the top thereof and fixedly attached along its opposed upper side edges to said second pair of members for holding said second pair of members in parallel relationship with predetermined spacing therebetween against forces urging them apart which are developed in the assembly when it is unfolded with said at least one of the cross frames in said extended position.
Claim 3
Dependent Claim
46 words
The improvement according to claim 1, wherein each interconnected pair of members of said first and second pairs of members which are connected by one of said 270° knuckle joints forms with its associated members of the back and bottom cross frames a generally quadrilateral substructure.
Claim 4
Dependent Claim
80 words
The improvement according to claim 2, wherein the members of each quadrilateral substructure are so related that the ratio of the length of each member of said first pair to that of its associated member of the bottom cross frame is equal to the ratio of the length of each member of said second pair to that of its associated member of the back cross frame, said lengths being taken between the pivotal connections at opposite ends of said members.
Claim 5
Dependent Claim
21 words
The improvement according to claim 1, wherein four wheel sets are provided, one at each corner of the bottom cross frame.
Claim 6
Dependent Claim
35 words
The improvement according to claim 4, wherein each wheel set is carried by a short downwardly curved portion extending beyond the pivot at a respective end of a respective member of the bottom cross frame.
Claim 7
Dependent Claim
26 words
The improvement according to claim 5, wherein said sack has four bottom corners, each connected to a respective said downwardly curved portion by an elastic loop.
Claim 8
Dependent Claim
57 words
The improvement according to claim 1, wherein each of the second pair of members has a handle member articulated thereto at its rear end by a respective knuckle joint operable to lock the handle member in a rearwards upwardly extending position and to release said handle member for folding alongside the members of said back cross frame.
Claim 9
Dependent Claim
32 words
The improvement according to claim 1, wherein said first and second pairs of members, as well as the members of said back and bottom cross frames, are of rigid tubular metallic construction.
Claim 10
Dependent Claim
60 words
The improvement according to claim 1, wherein the pivotal attachments at said first ends of said first and second pairs of members are pin connections at which the urging-apart forces are developed, the front and rear edges of said sack being under tension while said second pair of members are held in their parallel predetermined spaced relationship by said sack.
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) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |