US3580567A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic elevating mechanism for a paper feed platform of an automatic paper feed device for use with a photocopying machine, printing press, or the like
Assignee: Ricoh Co Ltd
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Filing: 1968-08-27
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Granted: 1971-05-25
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Expires: 1988-08-27
Abstract
Abstract When the height of a stack of papers to be copied or printed falls below a predetermined level, the level of the stack is sensed by a sensing roller which closes the circuit for a solenoid through a microswitch attached to the sensing roller. A blocking plate is pulled downwardly by the solenoid and a constantly reciprocating engaging pawl is thereby allowed to engage a ratchet wheel, thereby moving upwardly a rack in mesh with a pinion integral with the ratchet wheel, whereby a paper feed platform supported by the rack can be elevated up to a predetermined level.
Inventors
- 👤 Hideo Hashimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:25
CPC Classifications
B; B65; B65H; B65H1/00; B65H1/08; B65H1/18
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
326 words
In an automatic elevating mechanism for a vertically movable paper feed platform comprising a vertically movable rack attached to the paper feed platform in supporting relation thereto, a pinion meshed with the rack and rotatable about a fixed axis, a ratchet wheel connected to the pinion for rotation therewith, a reciprocable pawl placed to engage the teeth of the ratchet wheel and rotate said ratchet wheel in lifting direction to cause the rack to rise, a reverse rotation preventing pawl movable into an engaged position in which said reverse rotation prevention pawl engages the ratchet wheel and prevents said ratchet wheel from rotating in a lowering direction opposite to the lifting direction, a blocking member movable between a blocking position in which said blocking member prevents engagement of the reciprocable pawl with the ratchet wheel and a nonblocking position in which said blocking member allows said engagement, sensing means for detecting the level of the uppermost sheet of paper on the paper feed platform, and control means connected to said sensing means for moving the blocking member from the blocking to the nonblocking position when the sensing means detects absence of said uppermost sheet of paper at a preselected level and from the nonblocking to the blocking position when the sensing means detects the presence of said uppermost sheet of paper at the preselected level, the improvement comprising first means for moving the reverse rotation prevention pawl to a disengaged position in which said pawl does not prevent the ratchet wheel from rotating in the lowering direction; second means for moving the reciprocable pawl out of engagement with the ratchet wheel in response to movement of the reverse rotation prevention pawl to the disengaged position; and third means for guiding movement of the paper feed platform downward into a loading position upon movement of the reverse rotation prevention pawl into the disengaged position and movement of the reciprocable pawl out of engagement with the ratchet wheel.
Claim 2
Dependent Claim
326 words
In an automatic elevating mechanism for a vertically movable paper feed platform comprising a vertically movable rack attached to the paper feed platform in supporting relation thereto, a pinion meshed with the rack and rotatable about a fixed axis, a ratchet wheel connected to the pinion for rotation therewith, a reciprocable pawl placed to engage the teeth of the ratchet wheel and rotate said ratchet wheel in lifting direction to cause the rack to rise, a reverse rotation preventing pawl movable into an engaged position in which said reverse rotation prevention pawl engages the ratchet wheel and prevents said ratchet wheel from rotating in a lowering direction opposite to the lifting direction, a blocking member movable between a blocking position in which said blocking member prevents engagement of the reciprocable pawl with the ratchet wheel and a nonblocking position in which said blocking member allows said engagement, sensing means for detecting the level of the uppermost sheet of paper on the paper feed platform, and control means connected to said sensing means for moving the blocking member from the blocking to the nonblocking position when the sensing means detects absence of said uppermost sheet of paper at a preselected level and from the nonblocking to the blocking position when the sensing means detects the presence of said uppermost sheet of paper at the preselected level, the improvement comprising first means for moving the reverse rotation prevention pawl to a disengaged position in which said pawl does not prevent the ratchet wheel from rotating in the lowering direction; second means for moving the reciprocable pawl out of engagement with the ratchet wheel in response to movement of the reverse rotation prevention pawl to the disengaged position; and third means for guiding movement of the paper feed platform downward into a loading position upon movement of the reverse rotation prevention pawl into the disengaged position and movement of the reciprocable pawl out of engagement with the ratchet wheel.
Claim 3
Dependent Claim
15 words
The device of claim 1 comprising manually operable control means for activating the first means.
Claim 4
Dependent Claim
292 words
In an automatic elevating mechanism for a vertically movable paper feed platform comprising a vertically movable rack attached to the paper feed platform in supporting relation thereto, a pinion meshed with the rack and rotatable about a fixed axis, a ratchet wheel connected to the pinion for rotation therewith, a reciprocable pawl placed to engage the teeth of the ratchet wheel and rotate said ratchet wheel in lifting direction to cause the rack to rise, a reverse rotation preventing pawl movable into an engaged position in which said reverse rotation prevention pawl engages the ratchet wheel and prevents said ratchet wheel from rotating in a lowering direction opposite to the lifting direction, a blocking member movable between a blocking position in which said blocking member prevents engagement of the reciprocable pawl with the ratchet wheel and a nonblocking position in which said blocking member allows said engagement, the improvement comprising resilient means urging the blocking member into the blocking position; a solenoid connected to the blocking member adapted for activation by a signal current, said solenoid when so activated moving the blocking member into the nonblocking position; sensing means for detecting the level of the uppermost sheet of paper on the paper feed platform and transmitting the signal current to the solenoid through a signal-transmission circuit when said level falls below a predetermined position; manually operable means for moving the reverse rotation preventing pawl into a disengaged position in which said reverse rotation preventing pawl does not prevent rotation of the ratchet whEel; and switch means for breaking the signal transmission circuit when the reverse rotation preventing pawl is moved into the disengaged position, thereby inactivating the solenoid and allowing the resilient means to move the blocking member into the blocking position.
Claim 5
Dependent Claim
292 words
In an automatic elevating mechanism for a vertically movable paper feed platform comprising a vertically movable rack attached to the paper feed platform in supporting relation thereto, a pinion meshed with the rack and rotatable about a fixed axis, a ratchet wheel connected to the pinion for rotation therewith, a reciprocable pawl placed to engage the teeth of the ratchet wheel and rotate said ratchet wheel in lifting direction to cause the rack to rise, a reverse rotation preventing pawl movable into an engaged position in which said reverse rotation prevention pawl engages the ratchet wheel and prevents said ratchet wheel from rotating in a lowering direction opposite to the lifting direction, a blocking member movable between a blocking position in which said blocking member prevents engagement of the reciprocable pawl with the ratchet wheel and a nonblocking position in which said blocking member allows said engagement, the improvement comprising resilient means urging the blocking member into the blocking position; a solenoid connected to the blocking member adapted for activation by a signal current, said solenoid when so activated moving the blocking member into the nonblocking position; sensing means for detecting the level of the uppermost sheet of paper on the paper feed platform and transmitting the signal current to the solenoid through a signal-transmission circuit when said level falls below a predetermined position; manually operable means for moving the reverse rotation preventing pawl into a disengaged position in which said reverse rotation preventing pawl does not prevent rotation of the ratchet whEel; and switch means for breaking the signal transmission circuit when the reverse rotation preventing pawl is moved into the disengaged position, thereby inactivating the solenoid and allowing the resilient means to move the blocking member into the blocking 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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |