Patent US3934679A successfully refreshed from Google Patents.
US3934679A
Expired / Lapsed
US
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Retractable stacker guard
Assignee: Curtis Industries Inc
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Filing: 1974-10-21
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Granted: 1976-01-27
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Expires: 1994-10-21
Abstract
Abstract A retractable overhead guard for use on vertical lifting machines which protects an operator of such equipment from falling objects or material. The overhead guard swings down into protective position in response to vertical load lifting movement by the machine and retracts to a non-obstructing position in response to load-lowering movement of the machine.
Inventors
- 👤 Nathan S. Lieptz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:45
CPC Classifications
B; B66; B66F; B66F9/00; B66F9/06; B66F9/075; B66F9/07545; Y; Y10; Y10S; Y10S414/00; Y10S414/127
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
135 words
In a protective overhead guard for a vertical lifting machine having a vertical mast and having a member guided by and vertically movable on said mast for load-lifting, the combination of an overhead guard pivotally connected to said mast for angular displacement relatively thereto, first means associated with said overhead guard and cooperating with said movable member for raising said overhead guard pivotally to a retracted position in response to downward motion of said movable member, second means associated with said overhead guard and cooperating with said movable member for lowering said overhead guard about said pivotal connection to a substantially horizontal operator-protective position rearwardly of said mast in response to upward motion of said movable member, and third means mounted on said machine for supporting said overhead guard at rest in said operator-protective position.
Claim 2
Dependent Claim
135 words
In a protective overhead guard for a vertical lifting machine having a vertical mast and having a member guided by and vertically movable on said mast for load-lifting, the combination of an overhead guard pivotally connected to said mast for angular displacement relatively thereto, first means associated with said overhead guard and cooperating with said movable member for raising said overhead guard pivotally to a retracted position in response to downward motion of said movable member, second means associated with said overhead guard and cooperating with said movable member for lowering said overhead guard about said pivotal connection to a substantially horizontal operator-protective position rearwardly of said mast in response to upward motion of said movable member, and third means mounted on said machine for supporting said overhead guard at rest in said operator-protective position.
Claim 3
Dependent Claim
21 words
A combination as defined in claim 1, wherein said overhead guard comprises a flat panel member having a rigid peripheral frame.
Claim 4
Dependent Claim
16 words
A combination as defined in claim 2, wherein said panel member is perforated for visibility therethrough.
Claim 5
Dependent Claim
37 words
A combination as defined in claim 1, wherein said third means for supporting said overhead guard comprises a strut member interposed between said overhead guard and said machine for limiting downward angular displacement of said overhead guard.
Claim 6
Dependent Claim
61 words
A combination as defined in claim 4, wherein said strut member comprises an extendable assembly, one end of said assembly being movably attached to said overhead guard in spaced relationship to said pivotal connection, and the opposite end of said assembly being movably attached to said machine, whereby said assembly establishes a minimum load-bearing length for support of said overhead guard.
Claim 7
Dependent Claim
23 words
A combination as defined in claim 5, including a movable stop adjustably secured to said strut for selectively establishing said load-bearing length thereof.
Claim 8
Dependent Claim
19 words
A combination as defined in claim 5, including a spring compressively retained within said assembly for effecting extension thereof.
Claim 9
Dependent Claim
46 words
A combination as defined in claim 1, wherein said first means for raising said overhead guard comprises a lever element engageable by said movable member for translating said downward motion of said movable member into upward angular displacement of said overhead guard about said pivotal connection.
Claim 10
Dependent Claim
44 words
A combination as defined in claim 8, wherein said lever element extends to one side of said pivotal connection opposite to the body of said overhead guard, said lever being disposed in the path of movement of said movable member for camming engagement therewith.
Claim 11
Dependent Claim
42 words
A combination as defined in claim 9, wherein said body of said guard establishes a weight imbalance about said pivotal connection to provide said second means urging said guard downwardly toward operator-protective position in response to upward movement of said movable member.
Claim 12
Dependent Claim
46 words
A combination as defined in claim 1, wherein said first means for raising said overhead guard comprises a force-exerting member acting upon said overhead guard, said force-exerting member operating to raise said guard in response to downward motion of said movable member to a predetermined position.
Claim 13
Dependent Claim
32 words
A combination as defined in claim 11, wherein said force-exerting member is a spring energized in response to downward movement of said overhead guard and yieldably urging said guard to retracted position.
Claim 14
Dependent Claim
33 words
A combination as defined in claim 11, wherein said second means is a lever element engageable by said movable member for camming said guard into operator-protective position in opposition to said first means.
Claim 15
Dependent Claim
117 words
In a protective overhead guard for an operator-controlled vertical load-lifting machine having a longitudinally movable vertical-lifting member, the combination of an overhead guard pivotally connected to said machine for angular displacement relatively thereto, first means associated with said overhead guard and cooperating with said member for raising said guard axially about said pivotal connection to a retracted substantially upright position in response to downward longitudinal motion of said member to a load-carrying position below the operator, and second means associated with said guard and cooperating with said member for lowering said guard axially about said pivotal connection to an operator-protective position in response to upward longitudinal motion of said member toward a load-carrying position above the operator.
Claim 16
Dependent Claim
117 words
In a protective overhead guard for an operator-controlled vertical load-lifting machine having a longitudinally movable vertical-lifting member, the combination of an overhead guard pivotally connected to said machine for angular displacement relatively thereto, first means associated with said overhead guard and cooperating with said member for raising said guard axially about said pivotal connection to a retracted substantially upright position in response to downward longitudinal motion of said member to a load-carrying position below the operator, and second means associated with said guard and cooperating with said member for lowering said guard axially about said pivotal connection to an operator-protective position in response to upward longitudinal motion of said member toward a load-carrying position above the operator.
Claim 17
Dependent Claim
22 words
A combination as defined in claim 14, including guard-support members for limiting downward pivotal movement of said guard to a predetermined position.
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) | 1979-01-26 | 1979-07-28 | 1980-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-26 | 1983-07-28 | 1984-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-26 | 1987-07-28 | 1988-01-27 | $7700.00 | Window Closed / Lapsed |