GB2311253A

GB2311253A - Jig for stencil assembly

Info

Publication number: GB2311253A
Application number: GB9606058A
Authority: GB
Inventors: Anthony Clarke; David Patrick Clarkin
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-03-14
Filing date: 1996-03-22
Publication date: 1997-09-24
Anticipated expiration: 2016-03-22
Also published as: GB2311253B; GB9606058D0; IES960218A2; IES69538B2

Abstract

The jig facilitates the assembly of a cylindrical silk screen stencil (46) and two circular end rings (14). The jig has a base (18) having mounted thereon a chuck (20) with a centrally located pillar (22, fig 7), two support pillars (28, 29) for the jig when in a horizontal position, and a further pillar (30) which has mounted on its free end ring engaging means. In use the first end ring is engaged by the chuck and locked in position using plastics blocks pressed into position between the end ring and the chuck. A silk screen stencil (46) is placed over the pillar centrally located relative to the chuck to engage the end ring. A second end ring (14) is placed in the open end of the stencil to engage the pillar centrally located relative to the chuck. The end ring engaging means is then moved to engage the second end ring to position it correctly relative to the stencil. Once the stencil and the two end rings are positioned correctly relative to each other, the jig is turned through 90{ to stand on stud legs (31-33) mounted on the base and the support pillars. Adhesive is then applied to the stencil and end rings assembly to hold the assembly fixedly and securely together.

Description

A JIG This invention relates to a jig adapted to facilitate the mounting of an end ring on each of the two open ends of a cylindrical silk screen stencil, the assembly of silk screen stencil and two end rings being for use in a conventional silk screen printer.

At present the mounting of a cylindrical silk screen stencil on end rings is a relatively difficult task which requires a considerable degree of skill. Even with such skill it is usual that the extreme edges of the open ends of the cylindrical silk screen stencil do not lie flush with the relevant abutting surface of the end rings. This can lead to damage of the stencil and if the mounting is sufficiently inaccurate the assembly in use can render the printing job one of poor quality.

Another factor which requires mention is that when the stencil is mounted on the end rings it is necessary to fix usually by adhesive - the stencil to the end rings. The use of fixing means such as adhesive does require skill since existing known jigs are always in use vertically orientated which means that unless the adhesive is properly applied the adhesive may run downward onto the stencil which effectively can render the stencil unusable.

The present invention provides a jig to facilitate the assembly of a conventional cylindrical silk screen stencil and two conventional circular end rings the jig comprising a base upon which is mounted a conventional chuck mechanism having a centrally located pillar, the base also having mounted thereon another pillar the free end of which has secured thereto end ring engaging means whereby in use a first end ring is secured by the chuck, a stencil is placed over the pillar associated with the chuck to engage the end ring, a second end ring is placed into the free open end of the stencil to engage the free end of the pillar associated with the chuck, the end ring engaging means is then moved to engage the second end ring to position the said second end ring correctly relative to the stencil such that the free edges of the stencil are flush with the appropriate edge of the respective bases of each end ring prior to the application of a fixing means to secure the stencil to the end rings.

Preferably the in use top face of the pillar associated with the chuck has a centrally located spring loaded locating pin which in use engages a locating hole in the in use bottom face of the base of the second end ring.

Preferably the end ring engaging means comprises a pivotally mounted first-plate which for operative use is pivoted from an non-operative position to an end ring engaging position and a pivotally mounted second plate which is pivoted to engage the first plate in its operative position, the second plate carrying adjustable screw means to allow pressure to be applied to the first plate to force in use the second end ring into a correct assembly position relative to that edge of the stencil engaged with the second end ring.

It will also be understood that the jig may be constructed in metal and/or in an appropriate plastics material The invention will be understood from the following description of an embodiment thereof given by way of example only with reference to the accompanying drawings in which Fig 1 is a top plan view of one of the first end ring which is of a conventional and known construction.

Fig 2 is a side view of the end ring of Fig. 1.

Fig 3 is a bottom plan view of the end ring of Fig. 1.

Fig 4 is a top plan view of the second end ring which is also of a conventional and known construction.

Fig 5 is a side view of the end ring of Fig 4.

Fig 6 is a bottom plan view of the end ring of Fig. 4.

Fig 7 is a perspective view of a jig according to the present invention with one end ring shown in a locked position on the jig.

Fig 8 is a perspective view of the jig with the silk screen stencil and the end rings in a partially assembled position.

Fig 9 is a perspective view of the jig with the silk screen stencil and the end rings in an assembled position; and Fig 10 is a perspective view of a jig and assembled silk screen stencil and end rings turned into a horizontal orientation.

Referring to Figs 1-3 of the accompanying drawings the first end ring is of a metal and of a cylindrical construction with a base 10 and a stepped projecting flange 11 with an opening 12.

Referring to Figs 4-6 of the accompanying drawings the second end ring which is also of metal and of a cylindrical construction with a base 13 having a solid upwardly extending flange 14 with a circular recessed area 15. The bottom face 16 of the base 13 has a location hole 17.

The jig according to the present embodiment comprises a base 18 standing on stud legs 19. Mounted on the base 18 is a conventional chuck mechanism 20 with a conventional opening and closing adjusting mechanism actuated by a conventional key when inserted into the key hole 21.

The chuck 20 has a centrally located pillar 22 with a spring loaded locating pin 23 centrally located on the face 24 of the free end of the pillar 22. The chuck 20 has fixedly located around the pillar 22 the first end ring with base 10 upward. Plastic blocks 25, 26 and 27 are placed around the flange 11 of the first end ring in a forced fit between the face of the chuck 20 and the base 10 of the first end ring, to hold the end ring firmly in position.

The base 18 has three pillars 28, 29 and 30. The pillars 28 and 29 have at their free ends stud legs 31 and 32 respectively. The base 18 has complementary stud legs 33.

The pillar 30 has mounted on the its free end 35 a sleeve 26 carrying a plate 37 upon which is hingedly mounted for pivotal movement a plate 38 with a locating boss 39 secured on the plate 38 by a nut 40. Also mounted on the plate 37 on a pivot 41 is a plate 42 with an adjustable screw 43 located in a screw hole 44. The screw 43 has a handle 45 to facilitate the adjustable movement of the screw 43 in the screw hole 44.

A silk screen stencil 46 is first placed over the pillar 22 and the leading edge of the stencil is mounted on the base 10 of the first end ring with the leading edge of the stencil 46 abutting the plastics blocks 25, 26 and 27 such that the said leading edge of the stencil 46 is flush with the bottom edge of the base 10 of the first end ring. The second end ring is then carefully placed into the open end of the stencil 46 with the locating pin 23 engaging in the hole 17 on the bottom face 16 of the base 13 of the second end ring. This location of the pin 23 in the hole 17 serves to properly centre the second end ring in position. This partial assembly of the stencil 46 and the end rings is shown in Fig.8 of the accompanying drawings with the base 13 of the second end ring slightly proud of the top edge 47 of the stencil 46.

The plate 38 is pivoted downward such that the boss 39 engages in the recessed area 15. The plate 42 is pivoted horizontally to position the bottom of the screw 43 over a recess 48 on the in use top face 49 of the plate 38. By turning the handle 45 the screw 43 bears down on the plate 38 to allow the boss 39 to press down on the second end ring which in turn allows the end ring to press down against the spring loaded locating pin 23. In this manner the end ring is forced down to a position where the bottom face 16 of the base 13 abuts the face 24 of the pillar 22. In this position the top edge of the stencil is flush with the face of the base 13 of the second end ring as shown in Fig. 9 of the accompanying drawings.

When the assembly is complete as described above, the jig is turned through 90 to stand on the stud legs 31, 32 and 33. This allows one to apply adhesive to the end edges of the stencil 46 where they engage the end rings. This is achieved to advantage by simply rotating the stencil and end rings assembly while applying the adhesive. Once the adhesive has taken effect the assembly is released from the jig.

It will readily be appreciated that the jig of the present invention provides means to allow of the ready assembly of a silk screen stencil on two end rings while also minimising the potential for damage of the silk screen stencil. This leads to substantial monetary savings in a busy printing works - allowing also for the production of print orders with minimum disturbance due to good quality assembly and non-damaged stencils.

Claims

1. The present invention provides a jig to facilitate the assembly of a conventional cylindrical silk screen stencil and two conventional circular end rings the jig comprising a base upon which is mounted a conventional chuck mechanism having a centrally located pillar, the base also having mounted thereon another pillar the free end of which has secured thereto end ring engaging means whereby in use a first end ring is secured by the chuck, a stencil is placed over the pillar associated with the chuck to engage the end ring, a second end ring is placed into the free open end of the stencil to engage the free end of the pillar associated with the chuck, the end ring engaging means is then moved to engage the second end ring to position the said second enlt-ring correctly relative to the stencil such that the free edges of the stencil are flush with the appropriate edge of the respective bases of each end ring prior to the application of a fixing means to secure the stencil to the end rings.

2. A jig as claimed in Claim 1 in which the in use top face of the pillar associated with the chuck has a centrally located spring loaded locating pin which in use engaged a locating hole in the in use bottom face of the base of the second end ring.

3. A jig as claimed in Claim 1 in which the end ring engaging means comprises a pivotally mounted first plate which for operative use is pivoted from a non-operative position to an end ring engaging position and a pivotally mounted second plate which is pivoted to engage the first plate, in its operative position, the second plate carrying adjustable screw means to allow pressure to be applied to the first plate to force in use the second end ring into a correct assembly position relative to that edge of the stencil engaged with the second end ring.

4. A jig as claimed in anyone of the preceding claims in which the base has mounted thereon along one edge thereof two spaced apart pillars adapted in use to provide standing support for the jig when it is rotated through 900 from its vertical assembly position to a horizontal position.

5. A jig to facilitate the assembly of a conventional cylindrical silk screen stencil and two conventional circular end rings substantially as herein described with reference to Figs 7-10 of the accompanying drawings.