GB2231170A

GB2231170A - Mount for transparency

Info

Publication number: GB2231170A
Application number: GB8909772A
Authority: GB
Inventors: William Patrick Ryan
Original assignee: GEIMUPLAST
Current assignee: GEIMUPLAST
Priority date: 1989-04-28
Filing date: 1989-04-28
Publication date: 1990-11-07
Also published as: GB8909772D0

Abstract

A mount assembly for a photographic transparency comprising two superposable frames (3, 4) defining respective windows (2) which, when the frames are superimposed in correct mutual alignment with the transparency therebetween, are each in alignment with the picture area of the transparency, wherein one (3) of the frames has side walls (5) within which the other frame (4) is retained when the frames are assembled together and wherein frame (3) has lands (7, 8, 9) having grooves (12, 13, 14) which fit in ridges (24, 25, 30) on lands (22, 23, 24') of the other frame (3) when the frames are assembled together. There may also be recesses (19, 19', 20, 20') on frame (3) which accommodates pegs (26, 26', 27, 27') on frame (4). Ridges (10, 11) on frame (3) abut and guide the transparency in the mount. <IMAGE>

Description

MOUNT FOR TRANSPARENCY The present invention relates to mount assemblies for photographic transparencies.

A mount for photographic transparencies is known from British patent no. GB-A-960447. This known mount is a one piece injection moulding of plastics material comprising two superposable frames each defining a window which is aligned with the picture area of the transparency when the two frames are correctly superposed. The two frames are hinged together along one edge by two connecting fillets whose thickness is less than that of the frames. Since the fillets do not extend the full length of the side of the frames, when the frames are superposed the possibility exists that, when the mount is placed in automatically operating projection apparatus, the blade which is used to displace the mount into or out of the projection position may pass between the two frames and damage the transparency or the mount.

This problem is overcome by the mount known from GB-A-1003048. In this known mount, the two frames are linked by a hinge connection which extends substantially the full length of the frame. Furthermore, one frame has slightly smaller outer dimensions than those of the other frame which has an upstanding outer rim within which the smaller frame can fit when the two frames are superposed.

One difficulty with this known frame, however, is that the form of the hinge does not result in a clean edge to the 0 o mount at 90 to the major surfaces of the mount. The result is not pleasing to the eye and may also give rise to difficulties in the automatic projection apparatus mentioned above.

This problem has been solved by the mount construction shown in GB-A-1435366. In this known mount, the frames are connected to a spine by respective hinges about which the frames can be folded to assume the superposed position.

The outer face of the spine is substantially flat and forms an external surface of the mount substantially perpendicular to the major surfaces of the mount. A disadvantage of this mount is of course the relatively complex construction of the hinge.

It will be appreciated that the one piece construction of all the known mounts has the great advantage that generally speaking the relative position between the two frames is precisely defined by the hinge so that when the frames are folded to the superposed position no alignment difficulties arise. The best known solutions are fully satisfactory in this respect, but have the major disadvantage that the two frame halves must be of the same plastics material and thus of the same colour. It is thus impossible in an economic manner to make a mount in which the two frames are of different colours which may be of advantage for aesthetic reasons or in order to provide some form of colour coding. Colour coding is for example of advantage in that the different colours can be used to indicate to a user which is the "front" side of the mounted transparency.

In order to permit the two frames to be made easily of different coloured plastics, the two frames have to be moulded separately. However, this naturally gives rise to assembly and alignment difficulties.

According to one aspect of the present invention, there is provided a mount assembly for a photographic transparency comprising two superposable frames defining respective windows which, when the frames are superposed in correct mutual alignment with the transparency therebetween, are each in alignment with the picture area of the transparency, wherein one of the frames has side walls within which the other frame is retained when the frames are assembled together, and wherein a land is provided on each frame, that of one frame having a ridge thereon and that of the other frame having a groove thereon for receiving said ridge, such that when the frames are assembled together in correct mutual alignment said ridge is received in said groove.

Preferably, each frame member has at least two lands.

Preferably, each land has a respective groove or ridge.

Preferably, the or each land has an elongate rectangular shape and the associated ridge or groove extends the length of said rectangular shape.

Expediently, one frame has a land along one edge of which an abutment surface extends for guiding and positioning a photographic transparency.

Expediently, at least one land of one frame provides an upstanding peg receivable within a corresponding recess on a corresponding land of the other frame.

Preferably, said at least one land of one frame has two spaced upstanding pegs receivable within corresponding recesses on a corresponding land of the other frame.

For a better understanding of the 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: Fig. 1 shows a perspective view of assembled photographic mount; Fig. 2 shows an exploded perspective view of the mount of Fig. 1; Fig. 3 shows an exploded sectional view along the section line III-III of Fig. 2; Fig. 4 shows a cross section along the section line III-III, with the two frames in their assembled position; and Fig. 5 shows a partial sectional view along the line V-V of Fig. 2.

Referring to Fig. 1, a photographic mount 1 for receiving and holding a photographic transparency has a central window 2 through which the picture area of the transparency may be viewed. The mount comprises first and second frame members 3 and 4. The frame member 3 has an outer upstanding rim 5 within which the frame member 4 can fit. The outer rim 5 is cut away at two locations to provide entry recesses 6. These enable respective tongues to be inserted between the two frame members to enable one edge of the inner frame member 4 to be prised slightly away from the frame member 3 to permit insertion of the photographic transparency. Normally, this insertion and opening action is performed automatically by an appropriate machine.

It will be appreciated that the two frame members are secured together in the assembled condition by gluing or ultrasonic welding.

Referring now to Fig. 2, the internal structure and configuration of the two frame members is illustrated.

Referring first of all to the frame member 3, it will be seen that three elongate rectangular lands 7, 8 and 9 are provided on three sides of the frame member, the fourth side having no such land to permit insertion of the phtographic transparency. Closely adjoining the inner edge of each of lands 7 and 8, is provided an elongate ridge 10 or 11 whose inner surface provides an abutting and guide surface for a photographic transparency when correctly inserted into the mount. Each of lands 7, 8 and 9 furthermore has a respective channel 12, 13 and 14 extending the length of its major surface. These channels are for receiving corresponding elongate ridges on the other frame member for alignment and centering purposes as will be explained hereinafter.

Frame member 3 furthermore provides stop members 15 and 16 against which the photographic transparency abuts when it is fully inserted to its correct position. Similar stop members 17 and 18 are provided at the entry side of the mount. The surfaces of the stop members 17 and 18 are appropriately inclined to permit easy entry of the transparency.

Each of the lateral lands 7 and 8 additionally provides a pair of circular recesses 19, 19' and 20, 20'. These recesses are also provided for ensuring correct and accurate relative positioning of the two frame members, as will be explained hereinafter.

The frame member 3 furthermore provides a pair of clamping members 21 and 21' which cooperate with corresponding clamping members on the other frame member to ensure, by frictional engagement with the transparency, that the transparency remains firmly fixed in its correct inserted position, even under the heat of a projection bulb.

The other frame member 4 similarly provides three lands 22, 23 and 24' at positions corresponding to the lands 7, 8 and 9 of the first frame member 3. Each of lands 22 and 23 provides a respective elongate ridge 24 and 25 for cooperating with the grooves 12 and 13 of frame member 3, and provides a pair of upstanding pegs 26, 26' and 27, 27' for cooperating with the circular recesses 19, 19' and 20, 20' of frame member 3. Furthermore, along the edge of each of the lands 22 and 23 is provided an elongate channel 28 or 29 for receiving the respective ridge 10 or 11 of frame member 3. This enables the ridges 10 and 11 to protrude across the full thickness of the transparency and to provide a secure abutting surface for the transparency as clearly shown in Fig. 4.

An elongate ridge 30 is also provided on land 24' for cooperating with the elongate groove 14 on land 9.

Frame member 4 also provides recesses 31, 32, 33 and 34 for receiving the respective abutment members 15 to 18 of frame member 3. Similarly, two clamping members 35 and 35' are provided in alignment with the clamping members 21 and 21S.

Referring now to Fig. 3, a sectional view along the line III-III of Fig. 2 illustrates more exactly the geometrical shape of the various features of each frame member 3 and 4. A transparency 36 is indicated in its correct relative position between the frames. Fig. 4 is an enlarged view of the left hand portion of the frame members and transparency of Fig. 3 in the correctly assembled position. It may be seen how the lands 7 and 22 are in abutment and the elongate ridge 24 is received within the elongate channel 12. The peg 26' is received within the circular recess 19'. Furthermore, it may be seen how the transparency 36 abuts against a side surface of the elongate ridge 10 at one edge of the land 7. The ridge 10 is received within its corresponding recess 28 on the frame member 4.

Fig. 5. is provided to illustrate the configuration of stop member 17 and corresponding recess 33 at the entry side of the mount. Stop members 15 and 16 with recesses 31 and 32 may be configured in a similar way.

It will be appreciated that by the provision of the lands 7, 8 and 9 on frame member 3 and corresponding lands 22, 23 and 24' on frame member 4, reliable and exact mutual positioning of the frame members 3 and 4 may be easily achieved. When the elongate ridges 24, 25 and 30 are correctly inserted in the corresponding groove 12, 13 and 14 the chances of misalignment of the two frames are vitually negligible. Additional security is provided by means of the pegs 26, 26' and 27, 27' with their corresponding recesses 19, 19' and 20, 20'. In addition, when the frames are secured together, the lands 7, 8, 9 and 22, 23, 24' provide a firm and solid connection between the frames.

Thus, by use of the present invention, a two part transparency mount is a practical proposition, so that the two frame members of the mount may be manufactured in plastics material of different colours. The need for a complicated and somewhat delicate hinge construction is also avoided and the mounts may be assembled simply by placing the one frame member directly down on top of the other. The two frame members may be secured together by gluing or by ultrasonic welding along the lands.

In carrying out the assembly operation, a machine may be provided with a stack of frames 3 and a stack of complementary frames 4. The frames 4 are thinner and more flexible than frames 3, which have the peripheral rim 5.

The provision of the pegs 26, 26' and 27, 27' on frames 4 keeps them apart in the stack and facilitates removal of the frames from the stack one at a time to assemble the mounts.

It will be understood that the scope of the invention is not limited to the precise details of construction and configuration hereinbefore described, but rather by the following claims as interpreted by the description.

Claims

1. A mount assembly for a photographic transparency comprising two superposable frames defining respective windows which, when the frames are superimposed in correct mutual alignment with the transparency therebetween, are each in alignment with the picture area of the transparency, wherein one of the frames has side walls within which the other frame is retained when the frames are assembled together, and wherein a land is provided on each frame, that of one frame having a ridge thereon and that of the other frame having a groove thereon for receiving said ridge, such that when the frames are assembled together in correct mutual alignment said ridge is received in said groove.

2. An assembly according to claim 1 wherein each frame member has at least two lands.

3. An assembly according to claim 2 wherein each land has a respective groove or ridge.

4. An assembly according to any preceding claim wherein the or each land has an elongate rectangular shape and the associated ridge or groove extends the length of said rectangular shape.

5. An assembly according to any preceding claim wherein one frame has a land along one edge of which an abutment surface extends for guiding and positioning a photographic transparency.

6. An assembly according to any preceding claim wherein at least one land of one frame provides an upstanding peg receivable within a corresponding recess on a corresponding land of the other frame.

7. An assembly according to claim 6 wherein said at least one land of one frame has two spaced upstanding pegs receivable within corresponding recesses on a corresponding land of of the other frame.

8. A mount assembly for a photographic transparency substantially as hereinbefore described with reference to the accompanying drawings.