Patent US3578353A successfully refreshed from Google Patents.
US3578353A
Expired / Lapsed
US
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Handtruck apparatus
Assignee: Individual
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Filing: 1969-05-19
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Granted: 1971-05-11
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Expires: 1989-05-19
Abstract
Abstract A handtruck apparatus comprising a vertical frame supported on a pair of support wheels and including a pair of support handles at its upper extremity. A brace is pivotally supported on its upper end from the frame and includes a third wheel carried from its bottom extremity. A spring is connected between the brace and the frame in an over-the-center-type arrangement to normally bias such brace to its retracted position adjacent the frame and, when the brace is pivoted to an intermediate position, to bias such brace to its extended supporting position. A transverse pivot rod is carried from the frame and includes a first lever arm connected with an upwardly projecting actuating handle disposed adjacent one of said support handles and a second lever arm pivotally connected with a strut which engages the lower extremity of the brace whereby raising of the actuating handle kicks the lower extremity of the strut rearwardly to pivot the brace rearwardly to said intermediate position to enable the spring to pivot it to its supporting position.
Inventors
- 👤 Robert J Lockhart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:20
CPC Classifications
B; B62; B62B; B62B1/00; B62B1/002; B62B1/10; B62B1/14; B62B2203/00; B62B2203/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
133 words
Handtruck apparatus comprising: a vertical frame having, at least, one support handle on its upper extremity and including a pair of wheels; a brace pivotally supported on its upper extremity from said frame, said brace being pivotal between a retracted position, a center position, and a supporting position; limit means interconnecting said brace and frame for holding said brace in its supporting position; bias means normally biasing said brace to its retracted position and operative when said brace is pivoted outward to said center position to pivot said brace to its supporting position; and an actuating handle coupled with said brace whereby said handle may be manipulated to overcome said bias means to pivot said brace to said center position and enable said bias means to pivot said brace to said supporting position.
Claim 2
Dependent Claim
133 words
Handtruck apparatus comprising: a vertical frame having, at least, one support handle on its upper extremity and including a pair of wheels; a brace pivotally supported on its upper extremity from said frame, said brace being pivotal between a retracted position, a center position, and a supporting position; limit means interconnecting said brace and frame for holding said brace in its supporting position; bias means normally biasing said brace to its retracted position and operative when said brace is pivoted outward to said center position to pivot said brace to its supporting position; and an actuating handle coupled with said brace whereby said handle may be manipulated to overcome said bias means to pivot said brace to said center position and enable said bias means to pivot said brace to said supporting position.
Claim 3
Dependent Claim
55 words
Handtruck apparatus as set forth in claim 1 wherein: said brace includes a longitudinal slide; and said limit means includes a strut pivotally connected on one end to said frame and formed on its opposite end with a follower received in said slide and engageable with one end thereof to limit rotation of said brace.
Claim 4
Dependent Claim
42 words
Handtruck apparatus as set forth in claim 1 wherein: said limit means includes a strut coupled with said actuating handle for pulling said brace inwardly to said center position when said handle is pulled while said brace is in its supporting position.
Claim 5
Dependent Claim
78 words
Handtruck apparatus as set forth in claim 1 wherein: said limit means includes a pivot rod supported from said frame and coupled with said actuating handle, said rod being formed with an upwardly projecting lever arm, extending downwardly over said pivot rod, and engaged on its lower end with said brace, whereby raising of said actuating handle will pivot said strut about said pivot rod and force the lower extremity of said brace outwardly past said center position.
Claim 6
Dependent Claim
26 words
Handtruck apparatus as set forth in claim 1 that includes: a lifting platform supported from said frame; and lifting means for raising and lowering said platform.
Claim 7
Dependent Claim
43 words
Handtruck apparatus as set forth in claim 5 that includes: a caster wheel mounted on the underside of said platform for cooperating with said pair of wheels to support said truck in an upright position when said platform is in its lowered position.
Claim 8
Dependent Claim
18 words
Handtruck apparatus as set forth in claim 1 wherein: said actuating handle is disposed adjacent said support handle.
Claim 9
Dependent Claim
109 words
Handtruck apparatus as set forth in claim 1 wherein: said brace includes a longitudinal slide; and said limit means includes a horizontal pivot rod mounted on said frame and coupled with said actuating handle, said rod including an upwardly projecting lever arm, a strut pivotally connected with said lever arm and extending downwardly over said pivot rod and formed on its lower end with a follower received within said slide whereby raising of said handle will pivot said strut about said pivot rod and kick the lower extremity of said brace out past said center position to enable said bias means to move said brace to its supporting position.
Claim 10
Dependent Claim
44 words
Handtruck apparatus as set forth in claim 8 wherein: said lever arm is arranged to project forwardly of said pivot rod when said brace is in its supporting position whereby raising of said actuating handle will pivot said brace inwardly past said center position.
Claim 11
Dependent Claim
21 words
Handtruck apparatus as set forth in claim 1 that includes: a third wheel carried on the lower extremity of said brace.
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) | 1974-05-10 | 1974-11-09 | 1975-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-10 | 1978-11-09 | 1979-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-10 | 1982-11-09 | 1983-05-11 | $7700.00 | Window Closed / Lapsed |