US3584861A

US3584861A - Clamping device

Info

Publication number: US3584861A
Application number: US809363A
Authority: US
Inventors: William A Macdonald Jr
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1969-03-21
Filing date: 1969-03-21
Publication date: 1971-06-15
Anticipated expiration: 1988-06-15
Also published as: DE2013852A1; GB1308000A; FR2039683A5

Abstract

A device is provided for clamping the side edges of a receiver to hold it in place while a flexible electrode or a flexible photoconductor is stripped therefrom after charging so that the electrostatic attraction between the member being stripped away and the receiver sheet will not disturb the position of the receiver sheet. The clamps pivot against the receiver tending to stretch it laterally on the platen to hold it tight thereagainst.

Description

United States Patent William A. MacDonald, Jr. Rochester, N.Y.

Mar. 21, 1969 June 15, 1971 Eastman Kodak Company Rochester, N.Y.

Inventor Appl. No. Filed Patented Assignee CLAMPING DEVICE 7 Claims, 2 Drawing Figs.

[1.8. CI 269/154, 269/239 Int. Cl B25b 5/04 Field of Search 269/154,

[56] References Cited UNITED STATES PATENTS 1,158,686 11/1915 Henning 83/453 X 1,798,240 3/1931 Welter 271/59 UX 2,167,823 8/1939 Backhouse 271/59 2,685,927 8/1954 Fechter 269/154 X Primary Examiner-Andrew R. Juhasz Assistant Examiner-Donald D. Evenson Attorneys-Robert W. Hampton and Gary D. Fields ABSTRACT: A device is provided for clamping the side edges of a receiver to hold it in place while a flexible electrode or a flexible photoconductor is stripped therefrom after charging so that the electrostatic attraction between the member being stripped away and the receiver sheet will not disturb the position of the receiver sheet. The clamps pivot against the receiver tending to stretch it laterally on the platen to hold it tight thereagainst.

PATENTEDJUNISIBYI 3584861 ATTORNEYS WILLIAM A. MAC DONALD JR.

CLAMPING DEVICE CROSS-REFERENCE TO RELATED APPLICATION This invention may find utility in the device disclosed in my commonly assigned U.S. application Ser. No. 665,915, filed Sept. 6, 1967.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a clamping device, andmore particularly a clamping device for securing one of twomembers which are electrostatically held together while the other member is stripped therefrom.

2. Description of the Prior Art In electrophotography and related arts, it is common to bring a flexible member into intimate contact with another member for example, a photoconductive member and a receiver sheet or a flexible electrode and a,photoconductive receiver sheet, and apply an electrostatic field during charging which creates an electrostatic attraction between the members. Insuch arrangements, it is necessary to subsequently separate the members. If both members are moving it is relatively simple to separate them. However, in certain processes it is desirable to strip one from the other while they remain stationary. The difficulty is compounded where one ofthe members is a cut receiver sheet which is to be fed along a predetermined path after separation and hence must not be allowed to deviate from that path during separation.

SUMMARY OF THE INVENTION The present invention is adapted for use in an electrophotographic device, such as that disclosed in my commonly assigned copending U.S. application Ser. No. 665,915, filed Sept. 6, 1967 and now abandoned. In that device, a receiver in the form of a web having a nonconductive surface and a conductive backing is fed from a roll onto a conductive platen and cut to appropriate lengths to form receiver sheets. A flexible photoconductor having a conductive backing is lowered onto a receiver sheet on the platen and a potential applied between the platen and the conductive backing of the photoconductor. If the photoconductor is exposed to a pattern of radiation at the same time, an electrostatic image will be left on the receiver. After exposure, the flexible photoconductor is raised, thereby stripping it from the receiver sheet.

According to the present invention, to prevent electrostatic attraction from pulling the receiver sheet off the platen, clamp means are provided which are actuated as the photoconductor is raised to grip the side edges of the receiver sheet and hold it taut and flat as the photoconductor is pulled away. Subsequently, the clamps are released and the cut receiver sheet is fed through a suitable developing station where the electrostatic image thereon is toned and through the fusing station to fix the image thereon.

Alternatively, the receiver may be coated with a photoconductive material. In this case the member which is lowered and raised is merely a flexible electrode. In either case, there is an electrostatic attraction between the receiver and the other member tending to pull the receiver away from the platen when the members are separated.

More specifically, the clamping means may include paper guides which receive the edges of the sheet and have spaced slots therein through which clam'ps may be moved downwardly upon actuation of a clamping bar to clamp the receiver to the platen. The clamping bar is moved upon energization ofa solenoid. After the flexible member is separated from the receiver, the solenoid is deenergized permitting the clamps to be spring urged back to their initial position so that the receiver sheet may be fed through the paper guides to a toning station. The clamps pivot so that they tend to stretch the receiver tight across the platen.

Additional novel features and advantages of this invention will become apparent from the description which follows, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of the clamping device of this invention, with parts broken away for clarity of illustration; and

FIG. 2 is a transverse section, on an enlarged scale, taken along line 2-2 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT In accordance with this invention a platen I0 for supporting a receiver extends between spaced sidewalls 11 and 12 of a frame F which are interconnected by a bottom wall 13. The platen is conductive and may be suitably insulated from sidewalls 1] and 12 by means not shown. A length of material, such as a receiver sheet 14, which conveniently may include a conductive backing and an insulating layer, may be fed from a roll (not shown) under longitudinal extending paper guides l5 and 15' which include

flange portions

16 and 16, respectively, extending over the lateral edges of the receiver, as shown. As the receiver is advanced it passes under pressure roller 20 and 20' which cooperate with a pair of drive rollers therebelow, but not shown, which assist in feeding the paper onto platen 10 and assist in feeding it off of the platen after charging and exposure.

When the receiver is in position, it may be cut to length as disclosed in my above-mentioned application, and a flexible photoconductive member (not shown) can be lowered onto the receiver. For example, it may be lowered by a drive motor 40 which rotates a shaft 41 by means of pulley 42 to raise and lower photoconductor support arms 43 by means of excentrics 44. One end of the photoconductor is attached to supports 43 of FIG. 1, but best seen in my above-mentioned copending application. The other end of the photoconductor is connected to photoconductor support arm 45 which is pivotally connected to one end of a link 46 whose opposite end is pivoted to sidewall 11. Intermediate the ends of link 46 is a cam follower, such as roller 47 which rides on cam 48. Cam 48 is rotatably driven by motor 40 through pulley 49 to raise and lower support arm 45. A more detailed description of the mechanism for raising and lowering the photoconductor is contained in my above-mentioned application. While in the lowered position, a potential may be applied between platen l0 and a conductive backing on the photoconductor to place an electrostatic charge on the insulating surface of receiver 14. Subsequently to charging or simultaneously therewith the photoconductor may be exposed through its back surface so as to dissipate the charge and exposed areas on receiver 14 leaving an electrostatic image. After exposure the potential is discontinued and the photoconductor is raised from receiver 14 upon energization of motor 40.

Prior to raising the photoconductor, however, clamping devices D and D are actuated to clamp the receiver so that it will not be pulled out of paper guides 15 and 15'. Each clamping device includes a longitudinal channel having a

bottom wall

17 and 17 respectively, interconnecting short

upstanding walls

18 and 18 with longer upstanding walls 19 and 19', respectively.

Bottom walls

17 and 17 are attached, respectively, to guide 15 and 15. Clamping

arms

21 and 21 extend through

slots

22 and 22 respectively in

short legs

18 and 18 and through

slots

23 and 23 respectively in

long legs

19 and 19. As best seen in FIG. 2, slot 22 is relatively narrow and serves as a pivot-for clamping arm 21 whereas slot 23 is relatively long to permit pivotal movement of clamping arm 21. Slots 22 and 23' are similarly constructed. Each clamping arm is provided with a pressure pad such as pressure pad 24 adapted to moved downwardly through a slot such as slot 25 in flange 16 of paper guide 15 and into engagement with receiver I4, as described below. The opposite end of each clamping arm 21 is connected to a spring 26 which extends between the clamping arm and paper guide 15', as shown.

A pressure link, such as pressure link 27 extends along the outer side of leg 19, one end thereof being pivoted to a support or arm 28 which in turn is pivoted to leg 19. The other end link 28 is pivoted intermediate the ends of an arm 29 whose upper end is pivoted to leg 19. Spaced along link 27 above each clamping arm 21 is a pressure pad 31 adapted to engage and pivot pressure arms 21 about slots 22 against the force of spring 26, as described below.

A similar am 29' as shown in dotted lines in FIG. 1 is provided which is connected to similar linkage structure, not

shown. Arms 29 and 29' are pivotally connected at their lower ends to yokes 32 and 32', respectively, which in turn are fixedly attached to a pivotal rod 33 extending between and journaled in sidewalls 11 and 12. An outwardly extending end of rod 33 is connected to a lever 34 which in turn is connected to arm 35 of solenoid 36. When solenoid 36 is energized rod 33 is pivoted in a clockwise direction, as viewed in FIG. 1 which through yoke 32 which causes arms 29 to be pivoted in a counterclockwise direction so that pressure links 27 are moved downwardly causing pressure pads 31 to engage clamping arms 21. This causes clamping arms to pivot about slot 22 against the force of springs 26 so that clamping pads 24 moved downwardly through slots 25 into engagement with the side edges of receiver 14. Advantageously, as the clamping pads 24 moved downwardly they will also move outwardly slightly due to their pivotal movement about slot 22. This tends to stretch the receiver 14 in a lateral direction so that it is held taut and cannot be raised by the electrostatic attraction between the receiver and the photoconductor. When solenoid 36 is deenergized, spring 37, encircling arm 35, will cause rod 33 to be rotated in a counterclockwise direction thereby raising the pressure links. The clamping arms, such as clamping arms 21 will be pivoted back to their initial positions under the influence of springs 26.

When motor 40 is energized to raise the photoconductor, cam 48 will be rotated in a clockwise direction through the position shown in FIG. 1 so that the leading end of cam 48 closes switch 50 in the circuit to solenoid 36. As cam 48 continues to rotate, cam follower 47 will be raised to raise the photoconductor. While the photoconductor is in the fully raised position, the trailing end of cam 48 will pass the switch just before motor 40 is deenergized. This will cause switch 50 to be opened and solenoid 36 to be deenergized.

It will be understood that for some applications it may be desirable to use a receiver having a photoconductive surface thereon. In that case the member whichis raised and lowered may be a flexible conductive electrode.

From the foregoing, the advantages of this invention are readily apparent. A means has been provided wherein a receiver sheet may be firmly clamped to a platen while a flexible member is separated therefrom after charging so that the electrostatic attraction between the two will not cause the receiver to be pulled out of its guides. Conveniently, a series of pressure pads space along the longitudinal edges of the receiver are adapted to pivot through an arc so as to grip the edges of the receiver and pull it taut.

The invention has been described in detail with particular references to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

I claim:

1. An apparatus for clamping lateral edges of a length of material, said apparatus comprising:

a platen, having side edges, for supporting said length of material fed from a first end of said platen toward a second end thereof;

respective clamping means adjacent each side edge of said platen, each clamping means being movable from a first position spaced from said side edges to a second position in engagement with said platen to clamp the lateral edges of said length ofmaterial to said platen;

actuatable means coupled to each of said clamping means for moving said clamping means from said first position to said second position; and

respective guide means along each side edge of said platen for guiding said length of material, each said guide means having means defining at least one opening through which each of said clamping means is movable from said first position to said second position.

2. An apparatus for clamping lateral edges of a cut sheet comprising:

a platen, having side edges, for supporting said cut sheet fed from a first end of said platen toward a second end thereof;

a guide along each side edge of said platen for guiding said sheet, each guide having means defining a plurality of slots;

a plurality of clamping arms mounted adjacent each side edge of said platen for pivotal movement from a first position spaced from said side edges to a second position in engagement with said platen a foot on each of said clamping arms, each movable through one of said slots upon movement of said arms from said first position to said second position to clamp the lateral edges of said sheet against said platen; and

actuatable moving mean coupled to said clamping arms for moving said clamping arms from said first position to said second position 3. In an electrophotographic device, a receiver sheet clamping apparatus comprising:

a platen, having side edges, for supporting a receiver sheet having lateral edges, fed from a first end of said platen toward a second end thereof;

a guide along each side edge of said platen for guiding said receiver sheet, each guide having means defining a plurality of slots;

a support means along each side edge of said platen;

a plurality of clamping arms having feet thereon, said clamping arms being pivotally mounted on each of said support means for movement from a first position wherein said feet are spaced from said platen to a second position wherein said feet move through said slots into engagement with said platen to grip said lateral edges of said receiver sheet therebetween;

a pressure link extending along each of said support means engageable with said arms;

a pair of spaced pivot arms respectively pivotally interconnecting each of said pressure links with said respective support means;

linkage means connected to at least one of said pivot arms;

and

actuatable moving means connected to said linkage means for moving said pressure links into engagement with said clamping arms to moved said clamping arms from said first position to said second position.

4. In an electrophotographic device, as claimed in claim 3,

said support means comprising:

generally U-shaped members having a long leg and a short leg interconnected by a base, said base being attached to said platen with said short leg closest to said side edges of said platen;

means defining opposed slots in said long and short legs through which said arms extend, said slots in said short legs serving as pivots for said arms and said slots in said long legs being of sufficient size to facilitate pivotal movement of said arms from said first position to said second position.

5. In an electrophotographic device, as claimed in claim 4,

further comprising:

spring means connected to each of said arms urging said arms toward said first position.

6. In an electrophotographic device, as claimed in claim 3,

wherein said linkage means includes:

a rotatable rod extending transversely ofsaid platen;

a pair of spaced yokes each having a first end fixedly connected to said rod and each having a second end pivotally connected to one of each of said pair of pivot arms; and

a lever having a first and second end, said first end being fixedly connected to said rod; and

wherein said moving means includes:

a solenoid connected to said second end of said lever for rotating said rod upon actuation of said solenoid to move said pressure links into engagement with said clamping arms.

7. An apparatus for clamping lateral edges of a cut sheet comprising:

a plurality of clamping arms mounted adjacent each side edge of said platen for pivotal movement from a first posi-

Claims

1. An apparatus for clamping lateral edges of a length of material, said apparatus comprising: a platen, having side edges, for supporting said length of material fed from a first end of said platen toward a second end thereof; respective clamping means adjacent each side edge of said platen, each clamping means being movable from a first position spaced from said side edges to a second position in engagement with said platen to clamp the lateral edges of said length of material to said platen; actuatable means coupled to each of said clamping means for moving said clamping means from said first position to said second position; and respective guide means along each side edge of said platen for guiding said length of material, each said guide means having means defining at least one opening through which each of said clamping means is movable from said first position to said second position.

2. An apparatus for clamping lateral edges of a cut sheet comprising: a platen, having side edges, for supporting said cut sheet fed from a first end of said platen toward a second end thereof; a guide along each side edge of said platen for guiding said sheet, each guide having means defining a plurality of slots; a plurality of clamping arms mounted adjacent each side edge of said platen for pivotal movement from a first position spaced from said side edges to a second position in engagement with said platen a foot on each of said clamping arms, each movable through one of said slots upon movement of said arms from said first position to said second position to clamp the lateral edges of said sheet against said platen; and actuatable moving mean coupled to said clamping arms for moving said clamping arms from said first position to said second position

3. In an electrophotographic device, a receiver sheet clamping apparatus comprising: a platen, having side edges, for supporting a receiver sheet having lateral edges, fed from a first end of said platen toward a second end thereof; a guide along each side edge of said platen for guiding said receiver sheet, each guide having means defining a plurality of slots; a support means along each side edge of said platen; a plurality of clamping arms having feet thereon, said clamping arms being pivotally mounted on each of said support means for movement from a first position wherein said feet are spaced from said platen to a second position wherein said feet move through said slots into engagement with said platen to grip said lateral edges of said receiver sheet therebetween; a pressure link extending along each of said support means engageable with said arms; a pair of spaced pivot arms respectively pivotally interconnecting each of said pressure links with said respective support means; linkage means connected to at least one of said pivot arms; and actuatable moving means connected to said linkage means for moving said pressure links into engagement with said clamping arms to moved said clamping arms from said first position to said second position.

4. In an electrophotographic device, as claimed in claim 3, said support means comprising: generally U-shaped members having a long leg and a short leg interconnected by a base, said base being attached to said platen with said short leg closest to said side edges of said platen; means defining opposed slots in said long and short legs through which said arms extend, said slots in said short legs serving as pivots for said arms and said Slots in said long legs being of sufficient size to facilitate pivotal movement of said arms from said first position to said second position.

5. In an electrophotographic device, as claimed in claim 4, further comprising: spring means connected to each of said arms urging said arms toward said first position.

6. In an electrophotographic device, as claimed in claim 3, wherein said linkage means includes: a rotatable rod extending transversely of said platen; a pair of spaced yokes each having a first end fixedly connected to said rod and each having a second end pivotally connected to one of each of said pair of pivot arms; and a lever having a first and second end, said first end being fixedly connected to said rod; and wherein said moving means includes: a solenoid connected to said second end of said lever for rotating said rod upon actuation of said solenoid to move said pressure links into engagement with said clamping arms.

7. An apparatus for clamping lateral edges of a cut sheet comprising: a platen, having side edges, for supporting said cut sheet fed from a first end of said platen toward a second end thereof; a plurality of clamping arms mounted adjacent each side edge of said platen for pivotal movement from a first position spaced from said side edges to a second position in engagement with said platen; a generally U-shaped support extending along each side of said platen, each support having spaced legs with means defining a plurality of opposed slots therein through which said clamping arms extend, said slots in one of said legs serving as a fulcrum about which said arms pivot upon movement from one of said positions to the other of said positions; and actuatable moving means coupled to said clamping arms for moving said clamping arms from said first position to said second position.