US3980293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheet feeding with rear sheet separation
Assignee: Crathern and Smith Inc
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Filing: 1974-10-10
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Granted: 1976-09-14
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Expires: 1994-10-10
Abstract
Abstract A sheet feeding device includes an elevator table for supporting a stack of sheets and a front sheet vacuum head for lifting and presenting the front edge portion of the top sheet to feed rolls. A rear sheet separator includes a pivoted vacuum shoe having a curved, vacuumized face for lifting the rear edge portion of the top sheet prior to directing a rear air jet forwardly between the top upper sheet and the underlying sheet, and prior to feeding of the sheet. A rearwardly directed air jet at the front of the stack cooperates with the rear jet to provide an air cushion beneath the top sheet. The rear sheet separator shoe is mounted on upper and lower links which are actuated by an air cylinder to roll the vacuum shoe along the sheet as the shoe lifts the top sheet. Thus, the vacuum applied to the vacuum shoe is not relied upon to physically move the shoe, and the vacuum can be low enough so that a porous top sheet will substantially block off the vacuum ports in the shoe and the second sheet will not be lifted by the shoe. Hold down feet mounted on bell cranks that actuate the shoe through links hold down the rear edge of the second sheet while the rear edge of the top sheet is being lifted to receive air from the rear air jet. The hold down feet are raised from the stack before the feed rolls feed the top sheet.
Inventors
- 👤 Donald W. Shelmire
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:58
CPC Classifications
B; B65; B65H; B65H3/00; B65H3/08; B65H3/0808; B65H3/0816; B65H3/46; B65H3/48
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
215 words
Sheet feeding apparatus for feeding the top sheet from a stack of sheets supported by the stack elevator of a sheet processing machine, said apparatus comprising a pair of sheet feed rolls, a front vacuum head for lifting the front edge of the top sheet for presentation to the feed rolls, a vacuumized rear sheet separating shoe, means for pivoting the shoe for lifting the rear edge of the top sheet, rear sheet hold down means for engaging the second sheet after the rear edge of the top sheet has been lifted, and front nozzle means for directing an air jet rearwardly beneath the top sheet; the improvement comprising a rear nozzle for directing an air jet forwardly between the top sheet and the second sheet while the rear of the top sheet is lifted by said rear sheet separating shoe and the second sheet is engaged by said hold down means, said front nozzle directing an air jet rearwardly beneath the top sheet when it is lifted by said front vacuum head and cooperating with said rear nozzle for establishing an air cushion beneath the top sheet, and means for disengaging said rear sheet hold down means from the second sheet before said feed rolls grip and slide the top sheet across said stack.
Claim 2
Dependent Claim
215 words
Sheet feeding apparatus for feeding the top sheet from a stack of sheets supported by the stack elevator of a sheet processing machine, said apparatus comprising a pair of sheet feed rolls, a front vacuum head for lifting the front edge of the top sheet for presentation to the feed rolls, a vacuumized rear sheet separating shoe, means for pivoting the shoe for lifting the rear edge of the top sheet, rear sheet hold down means for engaging the second sheet after the rear edge of the top sheet has been lifted, and front nozzle means for directing an air jet rearwardly beneath the top sheet; the improvement comprising a rear nozzle for directing an air jet forwardly between the top sheet and the second sheet while the rear of the top sheet is lifted by said rear sheet separating shoe and the second sheet is engaged by said hold down means, said front nozzle directing an air jet rearwardly beneath the top sheet when it is lifted by said front vacuum head and cooperating with said rear nozzle for establishing an air cushion beneath the top sheet, and means for disengaging said rear sheet hold down means from the second sheet before said feed rolls grip and slide the top sheet across said stack.
Claim 3
Dependent Claim
38 words
The apparatus of claim 1, comprising means for holding the rear sheet separator shoe a short distance above the stack for opening an air passage beneath the top sheet at a zone under the rear sheet separating shoe.
Claim 4
Dependent Claim
29 words
The apparatus of claim 2, comprising means to maintain the vacuum on said rear sheet separator shoe when the top sheet is being pulled thereacross by said feed rolls.
Claim 5
Dependent Claim
40 words
The apparatus of claim 1, comprising a second rear nozzle for directing a second air jet forwardly against the rear edge of the stack, said second nozzle directing the second air jet below the jet from said first rear nozzle.
Claim 6
Dependent Claim
241 words
Rear sheet separator mechanism for lifting the rear portion of the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising support means mounted on the machine, a vacuumized rear sheet separating shoe for lifting a rear portion of the top sheet from the stack, pivot means for mounting said shoe on said support means, means for swinging said shoe about said pivot means, and a hold down foot mounted on said support means for engaging the second sheet after the rear top sheet portion has been lifted; the improvement wherein said shoe has a curved, sheet engaging face that is concentric with the shoe pivot means, a vacuum port opening to said shoe face, said means for swinging said shoe about its pivot means comprising first link means having an outer end connected to the shoe pivot means, second link means pivotally mounted on said support means and being pivotally connected to said shoe at a zone spaced from its pivot means, the inner end of said first link means being pivotally connected to said second link means, and actuator means connected to said link means for causing simultaneous pivoting of the shoe by said second link means and translation of the shoe pivot means by said first link means for rolling said curved face of the shoe along the top sheet.
Claim 7
Dependent Claim
241 words
Rear sheet separator mechanism for lifting the rear portion of the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising support means mounted on the machine, a vacuumized rear sheet separating shoe for lifting a rear portion of the top sheet from the stack, pivot means for mounting said shoe on said support means, means for swinging said shoe about said pivot means, and a hold down foot mounted on said support means for engaging the second sheet after the rear top sheet portion has been lifted; the improvement wherein said shoe has a curved, sheet engaging face that is concentric with the shoe pivot means, a vacuum port opening to said shoe face, said means for swinging said shoe about its pivot means comprising first link means having an outer end connected to the shoe pivot means, second link means pivotally mounted on said support means and being pivotally connected to said shoe at a zone spaced from its pivot means, the inner end of said first link means being pivotally connected to said second link means, and actuator means connected to said link means for causing simultaneous pivoting of the shoe by said second link means and translation of the shoe pivot means by said first link means for rolling said curved face of the shoe along the top sheet.
Claim 8
Independent Claim
134 words
The method of feeding the top sheet from a stack of sheets supported by the stack elevator of a sheet processing wherein the front edge of the top sheet is vacuum lifted and presented to feed rolls, the rear edge of the top sheet is vacuum lifted and the rear edge of the second sheet is held down; the improvement comprising the steps of lifting the rear edge of the top sheet and directing a rear jet of air forwardly between the top sheet and the second sheet while the second sheet is being held down and before lifting the front edge of the top sheet, and removing the hold down on the rear edge of the second sheet before the front edge of the top sheet is picked up by the feed rolls.
Claim 9
Independent Claim
134 words
The method of feeding the top sheet from a stack of sheets supported by the stack elevator of a sheet processing wherein the front edge of the top sheet is vacuum lifted and presented to feed rolls, the rear edge of the top sheet is vacuum lifted and the rear edge of the second sheet is held down; the improvement comprising the steps of lifting the rear edge of the top sheet and directing a rear jet of air forwardly between the top sheet and the second sheet while the second sheet is being held down and before lifting the front edge of the top sheet, and removing the hold down on the rear edge of the second sheet before the front edge of the top sheet is picked up by the feed rolls.
Claim 10
Dependent Claim
195 words
Rear sheet separator mechanism for lifting the rear portion of the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising support means mounted on the machine, a vacuumized rear sheet separating shoe for lifting a rear portion of the top sheet from the stack, said shoe having a pivot and a curved, sheet engaging face that is concentric with the pivot, means for pivotally mounting said shoe on said support means, means for swinging said shoe about said pivot, and a hold down foot mounted on said support means for engaging the second sheet after the rear top sheet portion has been lifted; the improvement wherein said means for mounting the shoe on said support means comprises vertically spaced link means, one of said link means being pivotally supported by said support means and being pivotally connected to said shoe pivot for translating the shoe, the other of said link means being connected to a portion of the shoe that is radially spaced from the shoe pivot and a linear actuator for operating said link means.
Claim 11
Dependent Claim
195 words
Rear sheet separator mechanism for lifting the rear portion of the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising support means mounted on the machine, a vacuumized rear sheet separating shoe for lifting a rear portion of the top sheet from the stack, said shoe having a pivot and a curved, sheet engaging face that is concentric with the pivot, means for pivotally mounting said shoe on said support means, means for swinging said shoe about said pivot, and a hold down foot mounted on said support means for engaging the second sheet after the rear top sheet portion has been lifted; the improvement wherein said means for mounting the shoe on said support means comprises vertically spaced link means, one of said link means being pivotally supported by said support means and being pivotally connected to said shoe pivot for translating the shoe, the other of said link means being connected to a portion of the shoe that is radially spaced from the shoe pivot and a linear actuator for operating said link means.
Claim 12
Dependent Claim
248 words
Mechanism for separating the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising support means mounted on the machine frame, a rear sheet separating shoe having a vacuumized face for lifting a portion of the top sheet from the stack, means on said support means for mounting said shoe, means for operating said shoe, and a hold down foot mounted on said support means for engaging the second sheet after the top sheet portion has been lifted; the improvement wherein said support means comprises a normally stationary support, link means pivotally mounted on said support, and pivot means for mounting said shoe on said link means, said vacuumized shoe face being curved and generally concentric with the shoe pivot means, said shoe operating means being connected to said link means for rotating said shoe about its pivot means, said link means comprising lever means pivotally mounted on said support means, lower link means pivotally projecting from said lever means with said shoe being pivotally mounted on said lower link means, upper link means extending between said lever means and said shoe for rocking the shoe about its pivot means when said lever means is operated, said shoe operating means comprising an actuator connected to said lever means for simultaneously pivoting the shoe and translating said shoe pivot means to roll the curved face of the shoe along the sheet.
Claim 13
Dependent Claim
248 words
Mechanism for separating the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising support means mounted on the machine frame, a rear sheet separating shoe having a vacuumized face for lifting a portion of the top sheet from the stack, means on said support means for mounting said shoe, means for operating said shoe, and a hold down foot mounted on said support means for engaging the second sheet after the top sheet portion has been lifted; the improvement wherein said support means comprises a normally stationary support, link means pivotally mounted on said support, and pivot means for mounting said shoe on said link means, said vacuumized shoe face being curved and generally concentric with the shoe pivot means, said shoe operating means being connected to said link means for rotating said shoe about its pivot means, said link means comprising lever means pivotally mounted on said support means, lower link means pivotally projecting from said lever means with said shoe being pivotally mounted on said lower link means, upper link means extending between said lever means and said shoe for rocking the shoe about its pivot means when said lever means is operated, said shoe operating means comprising an actuator connected to said lever means for simultaneously pivoting the shoe and translating said shoe pivot means to roll the curved face of the shoe along the sheet.
Claim 14
Dependent Claim
50 words
The mechanism of claim 8, wherein said lever means comprises a pair of bell crank levers straddling said shoe, one arm of each bell crank lever being connected to said actuator, the other arm of each bell crank lever forming the hold down foot for sheets remaining in the stack.
Claim 15
Dependent Claim
190 words
Mechanism for lifting a portion of the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising support means mounted on the machine, a sheet separating shoe having a pivot and a vacuumized face concentric with said pivot for lifting a rear portion of the top sheet from the stack, means for pivotally mounting said shoe on said support means, means for swinging said shoe about said pivot means, and a hold down foot mounted on said support means for engaging the second sheet after the top sheet portion has been lifted; the improvement wherein said means for pivotally mounting said shoe on said support means comprises first link means connected to said shoe pivot, said means for swinging said shoe about its pivot comprising second link means pivotally supported by said support means and pivotally connected to said shoe at a zone radially spaced from the shoe pivot, actuator means connected to said link means, and control means for operating said actuator means in timed relation with said sheet processing machine.
Claim 16
Dependent Claim
190 words
Mechanism for lifting a portion of the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising support means mounted on the machine, a sheet separating shoe having a pivot and a vacuumized face concentric with said pivot for lifting a rear portion of the top sheet from the stack, means for pivotally mounting said shoe on said support means, means for swinging said shoe about said pivot means, and a hold down foot mounted on said support means for engaging the second sheet after the top sheet portion has been lifted; the improvement wherein said means for pivotally mounting said shoe on said support means comprises first link means connected to said shoe pivot, said means for swinging said shoe about its pivot comprising second link means pivotally supported by said support means and pivotally connected to said shoe at a zone radially spaced from the shoe pivot, actuator means connected to said link means, and control means for operating said actuator means in timed relation with said sheet processing machine.
Claim 17
Dependent Claim
263 words
Mechanism for lifting a portion of the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising support means mounted on the machine, a sheet separating shoe having a pivot and a vacuumized face concentric with said pivot for lifting a rear portion of the top sheet from the stack, means for pivotally mounting said shoe on said support means, shoe operating means comprising means for swinging said shoe about said pivot in a direction to pick up the rear edge of the top sheet, and a hold down foot mounted on said support means for engaging the second sheet after the top sheet portion has been lifted; the improvement wherein said shoe mounting means comprises link means pivoted to said shoe pivot at an outer end and to said shoe operating means at an inner end, said operating means including an actuator for simultaneously operating said shoe swinging means and for imparting generally horizontal motion to the inner end pivot of said link means for linearly translating said shoe pivot in the plane of the top sheet while the shoe is being swung about its pivot for causing the curved face of said shoe to substantially roll along the top sheet in order to lift and curl an edge portion of the top sheet from the next underlying sheet, said link means and said shoe operating means freely accommodating vertical floating motion of said shoe when it is supported by sheets on said table.
Claim 18
Dependent Claim
263 words
Mechanism for lifting a portion of the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising support means mounted on the machine, a sheet separating shoe having a pivot and a vacuumized face concentric with said pivot for lifting a rear portion of the top sheet from the stack, means for pivotally mounting said shoe on said support means, shoe operating means comprising means for swinging said shoe about said pivot in a direction to pick up the rear edge of the top sheet, and a hold down foot mounted on said support means for engaging the second sheet after the top sheet portion has been lifted; the improvement wherein said shoe mounting means comprises link means pivoted to said shoe pivot at an outer end and to said shoe operating means at an inner end, said operating means including an actuator for simultaneously operating said shoe swinging means and for imparting generally horizontal motion to the inner end pivot of said link means for linearly translating said shoe pivot in the plane of the top sheet while the shoe is being swung about its pivot for causing the curved face of said shoe to substantially roll along the top sheet in order to lift and curl an edge portion of the top sheet from the next underlying sheet, said link means and said shoe operating means freely accommodating vertical floating motion of said shoe when it is supported by sheets on said table.
Claim 19
Dependent Claim
177 words
Mechanism for separating the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising normally stationary support means mounted on the machine frame, a rear sheet separating shoe having a pivot, a curved face concentric with the pivot extending from a vacuumized face for lifting a portion of the top sheet from the stack, link means pivoted on said support means for mounting said shoe pivot, means for rotating said shoe about its pivot, and a hold down foot mounted on said support means for engaging the second sheet after the top sheet portion has been lifted; the improvement wherein said shoe rotating means also comprises link means pivotally connected to said shoe and pivotally connected to said support means, both of said link means accommodating vertical floating motion of said shoe when it is supported by sheets on said table, stop means for limiting the downward motion of said shoe, and means for operating said shoe rotating means.
Claim 20
Dependent Claim
177 words
Mechanism for separating the top sheet from a stack of sheets supported by the elevator table of a sheet feeder for a sheet processing machine, said mechanism being of the type comprising normally stationary support means mounted on the machine frame, a rear sheet separating shoe having a pivot, a curved face concentric with the pivot extending from a vacuumized face for lifting a portion of the top sheet from the stack, link means pivoted on said support means for mounting said shoe pivot, means for rotating said shoe about its pivot, and a hold down foot mounted on said support means for engaging the second sheet after the top sheet portion has been lifted; the improvement wherein said shoe rotating means also comprises link means pivotally connected to said shoe and pivotally connected to said support means, both of said link means accommodating vertical floating motion of said shoe when it is supported by sheets on said table, stop means for limiting the downward motion of said shoe, and means for operating said shoe rotating means.
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) | 1979-09-14 | 1980-03-15 | 1980-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-14 | 1984-03-15 | 1984-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-14 | 1988-03-15 | 1988-09-14 | $7700.00 | Window Closed / Lapsed |