US3151554A

US3151554A - Perforated sheet supporting arrangement

Info

Publication number: US3151554A
Application number: US139801A
Authority: US
Inventors: Robert H Townsend
Original assignee: Fairchild Camera and Instrument Corp
Current assignee: Fairchild Semiconductor Corp
Priority date: 1961-09-21
Filing date: 1961-09-21
Publication date: 1964-10-06
Anticipated expiration: 1981-10-06

Description

. R. H. TOWNSEND Oct. 6, 1964 PERFORMED SHEET SUPPORTING ARRANGEMENT Filed Sept. 21. 1961 2 Sheets-Sheet 1 Oct. 6, 1964 R. H. TOWNSEND 3,151,554

PERFORATED sum SUPPORTING ARRANGEMENT Filed Sept; 21, 1961 2 Sheets-Sheet 2 FIG.3

W s mTI 3,151,554 PERFORATED SHEET SUPPORTING ARRANGEMENT Robert H. Townsend, Commack, N.Y., assigncr to Fairchild Camera and Instrument Corporation, a corporation of Delaware Filed Sept. 21, 1961, Ser. No. 139,801 5 Claims. (Cl. 101-4151) This invention relates to perforated sheet supporting arrangements and, while it is of general application, it is particularly suitable for supporting plastic sheets, such as photographic film sheets, on a cylinder for scanning, as in a photoelectric engraver of the type described and claimed in Patent Re. 23,914 to Boyajean.

Heretofore there have been devised many arrangement for supporting on a cylindrical member sheet-like elements having a series of supporting perforations at each end and used, for example, in proofing presses, duplicating machines, facsimile equipment, etc. In any such application, it is desirable that the sheet be supported uniformly on the cylindrical surface without wrinkling or buckling. This is usually accomplished by utilizing an adjustable tensioning member engaging the perforations of one end of the sheet and movable in a plane normal to the radius at the. point of support. However, if the sheet has appreciable stiffness and resilience,

it is diflicult to engage the sheet on such a tensioning member and to keep it engaged, as the end of the sheet tends to disengage the supporting lugs or pins and spring radially outwardly at the points of engagement. If the other end of the sheet engages fixed lugs or pins along the periphery of the cylinder, it also tends to spring outwardly and become disengaged.

Moreover, certain of the equipments of the type described are normally used in a photographic dark room, which presents some difficulty to the operator in securing an initial registration of the perforated sheets with the engaging lugs or pins.

It is an object of the invention, therefore, to provide a new and improved perforated sheet supporting arrangement in which the sheet is readily engageable by the support in a dark room.

It is another object of the invention to provide a new and improved perforated sheet supporting arrangement in which a resilient sheet may be readily engaged and tensioned about the supporting cylindrical surface substantially free from wrinkling and buckling.

In accordance with the invention, a supporting arrangement for an elongated resilient sheet having a plurality of supporting perforations along each end comprises a cylindrical supporting member having a recess for receiving the leading edge of a sheet to be supported,

at least one first supporting strip secured to the supporting member overlying the recess and parallel to its axis and having a planar portion substantially tangential to its cylindrical surface at one edge of such recess and provided with radially inwardly protruding elements positioned back from the edge of such recess to engage the perforations along one end of the sheet upon insertion under the planar strip portion, and at least one second supporting strip having a planar portion substantially tangential to the cylindrical surface at the other edge of the recess and extending in a direction opposite to the first strip and provided with elements positioned to engage the perforations along the other end of the sheet. The arrangement further comprises means for mounting the said second strip for motion substantially tangential to the cylindrical surface and spring means for biasing the second strip to tension an engaged sheet.

For a better understanding of the present invention,

United States Patent 0 together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawings, while its scope will be pointed out in the appended claims.

Referring now to the drawings:

FIG. 1 is a perspective view of a complete perforated sheet supporting arrangement embodying the invention;

FIG. 2 is an enlarged detailed end view of the sheet engaging elements of the arrangement of FIG. 1;

FIG. 3 is a fragmentary bottom perspective view of one of the sheet engaging elements of FIG. 1; while FIG. 4 is an end view of the other sheet engaging element of FIG. 1.

Referring now to FIG. 1 of the drawings, there is illustrated a portion of a supporting arrangement for an elongated sheet 10 having a plurality of supporting perforations 1%. along each end. The sheet 10 may be any suitable original copy to be reproduced, for example, a sheet of photographic film. Such a sheet and other sheets of plastic material have a certain amount of stiifness and resilience which present a problem in mounting them securely on a supporting cylinder without wrinkling or buckling.

The supporting arrangement includes a cylindrical supporting member 11 having a longitudinal recess 12. At least one supporting strip is secured to the cylindrical member 11 near its periphery. Specifically, as shown, a single elongated supporting strip 13 is secured to an elongated member 14 of rectangular cross-section by any suitable means such as machine screws 15. The mounting member 14 may, in turn, be secured to the cylindrical member 11 by any suitable means such as a series of machine screws 16. The supporting strip 13 is disposed parallel to the axis of the cylinder 11 and has a planar portion 13a substantially tangential to the cylindrical surface of the member 11 and provided with a plurality of radially inwardly protruding elements positioned to engage the perforations 10a along one end of the sheet 10 when underlying the tangential portion 13a. These protruding elements may be in the form of punch-outs 13b of a suitable dimension to engage the perforations 10a of the sheet 19.

The supporting strip 13 also is provided with a plurality of slots 130, shown in FIGS. 3 and 4, and a plurality of anchoring lugs 13d, which also may be punch-outs as shown. Projecting downwardly near one end of the strip 13b is a lug 21 secured to the strap 13 in any suitable fashion, which serves as a marginal guide for insertion of the film sheet 10. v

The supporting arrangement of the invention also includes at least one, and preferably a plurality of, second supporting

strips

17, 17. The strips 17 are in the form of an angle having a planar portion substantially tangential to the cylindrical surface of the member 11 and extending in a direction opposite to the planar portion 13a of the supporting strip 13. The strip 17 is provided with a plurality of lugs or

equivalent elements

18, 18, etc., protruding radially outwardly therefrom in a direction opposite to the protruding elements 13b of the supporting strip 13 and positioned to engage the perforations 10a, Ilia along the other end of the sheet 10 when overlying the

strips

17, 17. Obviously, the elements 18 may be secured to the strips 17 in any suitable manner but are shown as extending through an aperture and being upset therein.

The supporting arrangement of the invention further includes means for mounting the

strips

17, 17 for motion substantially tangential to the cylindrical surface of the member 11. Specifically, the strips 17 are provided with radially inwardly projecting pins 19 which engage and extend through the slots in the strip 13, each having a peripheral groove 1% and serving as an anchoring lug. There is also provided means for biasing the second strips to tension an engaged sheet 159. This biasing means may be in the form of a plurality of ail-shaped springs 2d, best shown in FIG. 3, which engage the punchout anchoring lugs 13d of the strip 13 and the anchoring lugs or pins 3% secured to the strips 17.

It is believed that the operation of the supporting arrangement of the invention to support and tension a sheet, st c h as a photographic film sheet, Will be apparent from the foregdihg description. In mounting a sheet on the supporting arrangement, the lefthand end, as viewed in FIG. 1, is inserted under the tangential portion 131: of the strip 13 with its righthand edge against the marginal guide lug 21 and is inserted until the perforations iltla, 1%, etc., engage the punch-out

lugs

13b, 13b, etc. This engagement is facilitated by the resilience of the sheet 19. Thus, the initial end of the sheet 19 may be inserted in the supporting arrangement purely by feel so that it can be readily inserted in a photographic dark room.

The sheet is then, of course, Wrapped around the cylinder 11 and the series of strips 17 are pushed forward, that is, to the right in FIGS. 1, 2, and 4, until the

lugs

18, 18 engage the corresponding perforations Mia, 16:: of the sheet 1%. The spring 20 then biases the strips 17 to tension the sheet Iltl about the cylinder ll. While a single strip 17, commensurate in length with the strip 13, might be used, it has been found preferable to use a series of short strips 17 as this aids in equalizing the ten sion along the entire edge of the sheet lit due to any possible irregularities in the spacing of the perforations or of the

lugs

18, 18, etc., on the strips 17. This operation of engaging the

lugs

13, 13 of each strip 17 with the corresponding perforations 16a, Iii-a of the sheet 10 can also be readily accomplished by feel in a photographic dark room. This application of the sheet to the supporting arrangement by feel is greatly facilitated by the under and over engagement With the supporting

strips

133 and 17, 17, etc., respectively.

While there has been described What is at present considered to be the preferred embodiment of the invention, it Will be obvious to those skilled in the art that various changes and modifications may be made therein Without departing from the invention, and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall Within the true spirit and scope of the invention.

What is claimed is:

1'. A supporting arrangement for an elongated resilient sheet having a plurality of supporting perforations along each end, comprising: a cylindrical supporting member having a longitudinal recess; at least one first supporting strip secured to said member adjacent said recess and parallel to its axis and having a planar portion substantially tangential to its cylindrical surface provided with protruding elements positioned to engage the perforations along one end of the sheet and provided also With a plurality of transverse slots; at least one second supporting strip having a planar portion substantially tangential to said cylindrical surface extending in a direction opposite to said first strip and provided With elements positioned to engage the perforations along the other end of the sheet, said second strip being provided with a plurality of pins engaging said slots in said first strip to provide for motion of said second strip substantially tangential to said cylindrical surface; and spring means for biasing said second strip relative to said first strip to tension an engaged sheet.

2. A supporting arrangement for an elongated resilient sheet having a plurality of supporting perforations along each end, comprising: a cylindrical supporting member having a longitudinal recess; at least one first supporting strip secured to said member adjacent said recess and parallel to its axis and having planar first and second portions substantially tangential to its cylindrical surfaces at opposite sides of said recess, said first portion being provided with protruding elements positioned to engage the perforations along one end of the sheet and said sec end portion being provided with a plurality of anchoring lugs; at least one second supporting strip having a planar portion substantially tangential to said cylindrical surface extending in a direction opposite to said first portion of said first strip and provided with elements positioned to engage the perforations along the other end of the sheet and a plurality of anchoring lugs; means for mounting said second strip for sliding motion relative to said second portion of said first strip and substantially tangential to said cylindrical surface; and a spring engaging the lugs of said first and second strips for biasing said second strip to tension an engaged sheet.

3. A supporting arrangement for an elongated resilient sheet having a plurality of supporting perforations along each end, comprising: a cylindrical supporting member having a recess for receiving the leading edge of a sheet to be supported; at least one first supporting strip secured to said member overlying said recess and parallel to its axis and having a planar portion substantially tangential to its cylindrical surface at one edge of said recess and provided With radially inwardly protruding elements positioned back from the edge of said recess to engage the perforations along one end of an underlying sheet upon insertion under said planar strip portion; at least one second supporting strip having a planar portion substantially tangential to said cylindrical surface at the other edge of said recess and extending in a direction opposite to said first strip and provided with radially outwardly protruding elements positioned to engage the perforations along the other end of an overlying sheet; means for mounting said second strip for motion substantially tangential to said cylindrical surface; and spring means for biasing said second strip to tension an engaged sheet.

4. A supporting arrangement for an elongated resilient sheet having a plurality of supporting perforations along each end, comprising: a cylindrical supporting member having a longitudinal recess; a first supporting strip secured to said member adjacent said recess and parallel to its axis and having a planar portion substantially tangential to its cylindrical surface provided with protruding elements positioned to engage the perforations along one end of the sheet; a plurality of second supporting strips each having a planar portion substantially tangential to said cylindrical surface extending in a direction opposite to said first strip and provided With elements positioned to engage the perforations along the other end of the sheet; means for mounting said second strips for independent translational and rotational motion substantially tangential to said cylindrical surface; and means for biasing said second strips to tension an engaged sheet, whereby each of said engaging elements of said second strips exerts a tension on its respective perforation independent of the alignments of said second strips.

5. A supporting arrangement for an elongated sheet having a plurality of supporting perforations along each end, comprising: a cylindrical supporting member having a longitudinal recess; at least one first supporting strip secured to said member overlying said recess, parallel to its axis, having a planar portion substantially tangential to its cylindrical surface provided With radially inwardly protruding elements positioned to engage the perforations along one end of an underlying sheet, and provided also with a plurality of transverse slots; at least one second supporting strip having a planar portion substantially tangential to said cylindrical surface, extending in a direction opposite to said first strip and provided With radially outwardly protruding elements positioned to engage the perforations along the other end of an overlying sheet, said second strip being provided with a plurality of pins engaging said slots in said first strip to provide for motion of said second strip substantially tangential to said cylindrical surface; and spring means for biasing said second strip relative to said first strip to tension an engaged sheet.

References Cited in the file of this patent UNITED STATES PATENTS English Mar. 5,

Curtis July 11,

Autere et al. Dec. 12,

FOREIGN PATENTS Canada Jan. 20,

Great Britain Feb. 17,