Printing screen and tensioning means

• US 3,991,677 A
• Filed: 04/17/1975
• Issued: 11/16/1976
• Est. Priority Date: 04/17/1975
• Status: Expired due to Term

• Current Assignee: Vincent H. Barnes
• Original Assignee: Vincent H. Barnes
• Inventors: Barnes, Vincent H.
• Primary Examiner(s): Crowder, Clifford D.
• Assistant Examiner(s): Suter, R. E.
• Application Number:
  US05/569,141
• Time in Patent Office: 579 Days
• Field of Search: 101/127, 101/127.1, 101/128.1, 101/415.1, 38/102-102.91, 26/54 R, 26/54 B
• US Class Current: 101/127.1
• CPC Class Codes: B41F 15/36 flat

Abstract

A printing screen and tensioning means including a rigid frame structure formed of channel shaped side members joined at the corners of the frame structure; the underside of each frame member receiving a parallelogram structure, each parallogram structure having a first and second side member connected by pivot links; the first side member being disposed adjacent the inner margin of the frame member and longitudinally movable by a screw drive; the second side member being guided for transverse movement in the frame member to and from the first member and having continuous screen attachment means; the printing screen having a continuous clip element at each side received on the attachment means, whereby upon operation of the screw drives the second side member applies a laterally outward force for uniformly stretching a corresponding side of the printing screen.

Claims

1. A printing screen and tensioning means, comprising:

a. a printing screen having a central printing area and marginal areas extending beyond the printing area;

b. a reinforcing strip secured to selected marginal areas to resist tension and including a lengthwise extending separable attachment element;

c. a frame structure having four sides and dimensioned to overlie, when in use, the marginal areas of the printing screen;

d. a parallelogram structure carried by each of the sides of the frame structure corresponding to the locations of the reinforcing strips;

e. each parallelogram structure including a drive bar restricted to movement parallel to the corresponding reinforcing strip;

a tension bar restricted to movement transverse to the reinforcing strip; and

links pivotally connecting corresponding drive and tension bars;

f. a longitudinally extending attachment element on each tension bar separably engageable with the attachment element of a corresponding reinforcing strip;

g. and a screw member carried by the frame structure and accessible externally thereof, the screw member being secured to the drive bar to effect movement thereof.

2. A printing screen and tensioning means, as defined in claim 1, wherein:

a. the frame structure is formed by four right-angularly disposed channel shaped side members having inner and outer flanges joined by a web and disposed, when arranged for use, with the side members extending downwardly, the inner flange engaging the printing screen.

3. A printing screen and tensioning means, as defined in claim 2, wherein:

a. the drive bars are disposed contiguous to the inner flanges of the side members;

b. said screw member extends in alignment from one end of each drive bar across the adjacent side member for external access to effect movement of the corresponding drive bar thereby to adjust the tension of the printing screen;

c. and each side member is provided with transverse guide means to confine the corresponding tension bar to movement to and from the printing screen.

4. A printing screen and tensioning means, comprising:

a. a printing screen having a central printing area bordered by marginal areas;

b. a frame structure having sides overlying the marginal areas and having coplanar lower edges engaging the marginal areas;

c. a parallelogram structure carried by each of selected sides of the frame structure;

d. each parallelogram structure including a tension bar, extending lengthwise with respect to each selected side of the frame structure, and cross pins extending crosswise thereto for guiding the tension bar to and from the corresponding marginal area of the printing screen;

e. each parallelogram structure also including a drive bar extending parallel to the tension bar, means for guiding the drive bar in a direction lengthwise of the tension bar, and link members joining the drive bar and tension bar to effect uniform movement of the tension bar to and from the corresponding marginal area of the printing screen upon lengthwise movement of the drive bar;

f. attachment means joining the tension bar to the corresponding marginal area of the printing screen;

g. and an operating member extending from the drive bar and carried by the frame structure to cause lengthwise movement of the tension bar to effect uniform stretching of the printing screen.

5. A printing screen and tensioning means, as defined in claim 4, wherein:

a. the frame structure includes four sides in right angular relation;

b. two marginal areas of the printing screen are fixed;

c. and the remaining two marginal areas form said selected sides and are attached to said parallelogram structures.

6. A printing screen and tensioning means, as defined in claim 4, wherein:

a. the frame structure includes four selected sides in right angular relation;

b. and a parallelogram structure is provided at each of the four sides of the frame structure.

7. A printing screen and tensioning means, as defined in claim 4, wherein:

a. said attachment means includes a hook element and a rib element, the elements being releasibly engageable and coextensive with a corresponding marginal area.