GB2167015A

GB2167015A - Proportional rule device for defining an area on a plane surface

Info

Publication number: GB2167015A
Application number: GB08428718A
Authority: GB
Inventors: Colin George Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-11-14
Filing date: 1984-11-14
Publication date: 1986-05-21
Also published as: GB8428718D0

Abstract

A proportional rule device is provided for indicating or outlining on a photograph, negative, slide, drawing or the like a desired size area for subsequent masking therearound and reproduction. The device includes a pair of frame members (2) each substantially L-shaped in plan and made of rigid or semi-rigid sheet material, and means for releasably and adjustably interconnecting the two frame members (2) slidably one on top of the other with the inner edges (3) of one of the substantially L-shaped frame members (2) directed towards and cooperating with the inner edges (3) of the other substantially L-shaped frame member (2) to outline and define therebetween a rectangular area corresponding to the desired size area. <IMAGE>

Description

SPECIFICATION Proportional rule device This invention relates to a proportional rule device for indicating or outlining on a photograph, negative, slide, drawing or the like a desired size area for subsequent masking therearound and reproduction.

Designers, photographers and art directors concerned with reproduction or printing of photographs frequently require to visualize on a proof negative, slide or print an area or portion thereof which is to be reproduced or printed. Frequently this area or portion of the negative, slide or print has to be reproduced in a standard paper size such as A4 or a standard slide size such as 3 centimetres by 2 centimetres for a standard 35 mm slide. Once the area of the negative, slide or print required to be reproduced has been established it is masked off for subsequent printing.

Customarily the desired area on a negative, slide or print to be reproduced is established by means of straight edged pieces of card or paper which are slid around on top of the proof negative, slide or print to act as a sliding mask which can be moved about on the proof until the desired portion for reproduction has been outlined by the straight edges of the card or paper. As will readily be appreciated this procedure is relatively imprecise with the outlining pieces of card or paper being easily displaced in angle and position relative to one another and to the proof, so distorting or falsifying the desired area initially outlined thereby on the proof.Moreover the actual size of the area outlined on the proof can only be measured by means a separate ruler which is both difficult to manipulate in conjunction with the straight edged paper or card pieces used for masking and an additional means for displacing the latter inadvertently.

There is thus a need for a generally improved device for indicating on a photograph, negative,slide, drawing or the like a desired size area for subsequent masking and reproduction.

According to the present invention there is provided a proportional rule device for indicating or outlining on a photograph, negative, slide, drawing or the like a desired size area for subsequent masking therearound and reproduction, including a pair of frame members each substantially L-shaped in plan and made of rigid or semi-rigid sheet material, and means for releasably and adjustably interconnecting the two frame members slidably one cn top of the other with the inner edges of one of the substantially L-shaped frame members directed towards and cooperating with the inner edges of the other substantially L-shaped frame member to outline and define therebetween a rectangular area corresponding to the desired size area, which area is variable by movement of the frame members relative to one another to cause the inner edges of one frame member to approach closer or move further away from the inner edges of the other frame member.

Advantageously each limb of each substantially L-shaped frame member has an elongated slot therethrough extending in the limb in the direction of the longitudinal axis thereof, and the means for interconnecting the two frame members includes two bolts each having a head portion and a smaller diameter threaded shank portion, and two complimentary threaded nuts engageable on the shank portions, the arrangement being such that with the two frame members slidably located one on top of the other as aforesaid, and with one slotted limb of one frame member transversely overlying one slotted limb on the other frame member and the other slotted limb of said one frame member transversely overlying the other slotted limb of the other slotted frame member, each bolt shank portion projects through the two communicating slots in a respective pair of transversely overlying limbs, with the bolt head portion on one side of one of the transversely overlying pair of limbs, for adjustable screw threaded engagement by the associated nut on the other side of said one of the transversely overlying pair of limbs releasably to clamp the respective limbs between the associates bolt head portion and nut in any desired position along the respective communicating slots corresponding to the desired size area defined between the frame member facing inner edges.

Conveniently at least one said frame member has at least one linear measuring scale located along at least one limb thereof adjacent the limb inner edge or slot.

Conveniently one frame member includes at least one scale on each limb thereof which scales indicate one or more standard slide or paper sizes, or length in metric or imperial units.

Conveniently each frame member is made of plastics material, preferably transparent.

Advantageously each frame member inner edge is dark coloured to facilitate visibility.

Preferably each nut is frustoconical in shape.

For a better understanding of the present invention and to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a plan view from above of one embodiment of a proportional rule device according to the present invention, and Figure 2 is a perspective view of the device of Figure 1.

As shown in the accompanying drawings a proportional rule device 1 according to one embodiment of the invention basically includes a pair of frame members 2 and means for releasably and interconnecting the two frame members slidably one on top of the other. Each frame member 2 is made from rigid or semi-rigid sheet material, such as plastics material, and preferably is transparent as illustrated.

As can be seen from the drawings each frame member 2 is substantially L-shaped in plan and the two frame members are releasably and adjustably interconnected in slidable fashion one on top of the other with inner edges 3 of one of the frame members 2 directed towards and cooperating with the inner edges 3 of the other frame member 2 to outline and define therebetween a rectangular area corresponding to the desired size area to be indicated or outlined on a photograph, negative, slide, drawing or the like. This area is variable by movement of the frame members 2 relative to one another to cause the inner edges 3 of one frame member 2 to approach closer or move further away from the inner edges 3 of the other frame member 2.Advantageously each frame member inner edge 3 is dark coloured, for example by being painted dark blue or black, to facilitate visibility of the edge when located over a photograph or the like.

Each frame member 2 has two limbs 4 and each limb 4 has an elongated slot 5 therethrough extending in the limb in the direction of the longitudinal axis thereof. The means provided for interconnecting the two frame members 2 includes two bolts each having a head portion and a smaller diameter threaded shank portion and two complementary threaded nuts 6, conveniently of frustoconical shape, engageable on the shank portions of the bolts. In the drawings only the nuts 6 are visible.

Thus with the two frame members 2 slidably located one on top of the other as shown in Figures 1 and 2, and with one slotted limb 4 of one frame member transversely overlying one slotted limb 4 of the other frame member 2 and the other slotted limb 4 of said one frame member transversely overlying the other slotted limb 4 of the other frame member 2 each bolt shank portion projects through the two communicating slots 5 in a respective pair of transverse overlying limbs 4.In this position the bolt head portion lies on one side of one of the transversely overlying pair of limbs 4 and the associated nut 6 is screw threadably engaged on the bolt shank portion on the other side of the said one of the transversely overlying pair of limbs 4 releasably to clamp the respective limbs 4 between the associated bolt head portion and nut 6, as illustrated, in any desired position along the respective communicating slots 5. Thus with the two frame members releasably and loosely interconnected by means of the bolts and nuts 6 in the communicating slots 5 of crossed limbs 4 the two frame members may be moved towards or away from one another by slidable movement of the slotted limbs relative to one another about their respective bolts.

In this way the size of the area to be found on an underlying proof negative, slide or print, may be adjusted in size and set on the rule to correspond to a paper or slide size set out on the scales 8, whereupon the nuts may be tightened temporarily to secure the frame members immovably together to define the desired size area. The rule defining the desired size area between the edges 3 may then be moved freely over the proof negative, slide or print, without disturbing the area set on the rule, until the required location is reached for subsequent masking or marking out. The rule may then be removed and reset to any other desired size area for further use.

Claims

1. A proportional rule device for indicating or outlining on a photograph, negative, slide, drawing or the like a desired size area for subsequent masking therearound and reproduction, including a pair of frame members each substantially L-shaped in plan and made of rigid or semi-rigid sheet material, and means for releasably and adjustably interconnecting the two frame members slidably one on top of the other with the inner edges of one of the substantially L-shaped frame members directed towards and cooperating with the inner edges of the other substantially L-shaped frame member to outline and define therebtween a rectangular area corresponding to the desired size area, which area is variable by movement of the frame members relative to one another to cause the inner edges of one frame member to approach closer or move further away from the inner edges of the other frame member.

2. A device according to claim 1, wherein each limb of each substantially L-shaped frame member has an elongated slot therethrough extending in the limb in the direction of the longitudinal axis thereof, and the means for interconnecting the two frame members includes two bolts each having a head portion and a smaller diameter threaded shank portion, and two complementary threaded nuts engageable on the shank portions, the arrangement being such that with the two frame members slidably located one on top of the other as aforesaid, and with one slotted limb of one frame member transversely overlying one slotted limb on the other frame member and the other slotted limb of said one frame member transversely overlying the other slotted limb of the other slotted frame member, each bolt shank portion projects through the two communicating slots in a respective pair of transversely overlying limbs, with the bolt head portion on one side of one of the transversely overlying pair of limbs, for adjustable screw threaded engagement by the associated nut on the other side of said one of the transversely overlying pair of limbs releasably to clamp the respective limbs between the associates bolt head portion and nut in any desired position along the respective communicating slots corresponding to the desired size area defined between the frame member facing inner edges.

3. A device according to claim 1 or claim 2, wherein at least one said frame member has at least one linear measuring scale located along at least one limb thereof adjacent the limb inner edge or slot.

4. A device according to any one of claims 1 to 3, wherein one frame member includes at least one scale on each limb thereof which scales indicate one or more standard slide or paper sizes, or length in metric or imperial units.

5. A device according to any one of claims 1 to 4, wherein each frame member is made of plastics material.

6. A device according to claim 5, wherein each frame member is made of transparent plastics ma terial.

7. A device according to any one of claims 1 to 6, wherein each frame member inner edge is dark coloured to facilitate visibility.

8. A device according to claim 2, wherein each nut is frustoconical in shape.

9. A proportional rule device substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.