GB2093200A - Rear Cover for a Camera Housing - Google Patents

Abstract

A cover 3 is adapted to close an opening in a camera housing 1 through which access can be gained to a film compartment, and comprises a relatively rigid section 4 having ribs 3d thereon and two relatively elastic sections 5 on either side thereof. The ribs 3d define a generally flat pressure surface which confronts a film guide surface 1b in the film compartment, and when the cover 3 is closed the elasticity of the sections 5 causes the pressure surface to be urged against the guide surface 1b. The conventional film pressure plate can thus be dispensed with, enabling the cover to be made of relatively small thickness. Where the camera is adapted to receive cassettes of film, rather than film in cartridges or on spools, the guide surface 1b is replaced by a support surface for a web portion of the cassette, and the pressure surface defined by the ribs 3d takes the place of the usual cassette applicator springs. <IMAGE>

Description

SPECIFICATION Rear Cover for a Camera Housing This invention relates to a rear cover for a camera housing, and to a camera including such a cover.

It is the usual practice to enable access to be gained to a film compartment of a camera through an opening in the camera housing which can be closed by a cover. Where the camera is adapted to receive film loaded in a cassette comprising a storage area, a film take-up area and a connecting web portion therebetween, it is necessary to fit applicator springs to the cover to press the web portion against a support surface in the film compartment. Where the camera is intended to receive film which is transported from a cartridge to a take-up spool or from a roll film spool to another spool, the cover must be provided with a resilient pressure plate to urge the film against a guide surface in the film compartment. The need to provide such applicator springs or such a pressure plate entails a higher outlay in the manufacture of the cover.

In addition, the cover must be made of a certain minimum thickness because, on the one hand, the applicator springs or the pressure plate must be accommodated with its thickness and, on the other hand, a certain amount of material strength is required in order to prevent the cover from being twisted or becoming warped under the effects of the resilient forces imposed by the applicator spring or the pressure plate.

It is an object of the present invention to provide a rear cover for a camera housing which is designed in a more cost-and space-saving manner.

According to one aspect of the present invention there is provided a rear cover for a camera housing which includes a guide surface for a film or a support surface for a web of a film cassette, the rear cover comprising a first region which is reinforced and which presents an integral, generally planar pressure surface to said guide or support surface, and resiliently deformable second regions which are formed integrally with the first region and which, when the cover iS in a closed position on said housing, are resiliently deformed to urge the pressure surface towards said guide or support surface.

According to a second aspect of the present invention, there is provided a camera comprising a housing having an opening therein through which access can be gained to a film compartment, the film compartment including a guide surface for a film or a support surface for the web of a film cassette, and a cover for closing the opening in the housing, the cover comprising a first region-which is reinforced and which presents an integral, generally planar pressure surface to the guide or support surface, and resiliently deformable second regions which are formed integrally with the first region and which, when the cover closes said opening, are resiliently deformed to urge the pressure surface towards the guide or support surface.

Preferably, two second regions are provided on opposite sides of the first region, one of the second regions being provided with bearing elements whereby the cover is attached to the housing, the other second region being provided with locking elements whereby the cover can be retained in a position wherein it closes the opening.

The thickness of the second regions may decrease in a direction away from the first region and towards the bearing and locking elements respectively. In the case where the pressure surface is formed by a plurality of ribs which project from a surface of the cover which faces the film compartment, the heights of the ribs may also decrease in a direction towards the bearing and locking elements, corresponding to the curvature of the cover.

Desirably, each of the second regions is slightly concave to the film compartment when the cover closes the opening in the housing.

Where the pressure surface is defined by a plurality of ribs as aforesaid, the ribs are conveniently all of the same height. The ribs may be elongate and disposed parallel to each other (and preferably also parallel to the direction of film transport), or they may be in the form of internesting rectangles, for example. To facilitate their production by moulding, the ribs can be of trapezoidal cross-section. Where the camera includes a rotatable sprocket wheel which is adapted to engage perforations in the film, the gap between adjacent ribs can be increased in the vicinity of the sprocket wheel to allow room for the latter to rotate.

Advantageously, a continuous light-sealing ridge is provided on the cover and engages in a corresponding groove in the housing when the cover closes said opening, the light-sealing ridge preferably extending continuously around the film compartment when the cover closes the opening.

The ridge can include two sections which are spaced apart transversely of the direction of film transportation, the separation of the two sections being reduced in the region of the guide or support surface. In this case, the area where the separation of the two sections is reduced can have substantially the same extent as the reinforced pressure surface with respect to the direction of film transportation, so that the second portions are able to flex about the boundary of the reinforced pressure surface.

Desirably, the cover is moulded as a single piece from plastics material.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a sectional plan view of part of a camera according to the present invention, showing in particular a rear cover for the camera housing; Figure 2 is a section taken along the line Il-Il in Figure 1; and Figure 3 is a view in the direction of arrow Ill in Figure 1, showing the aforesaid rear cover.

The illustrated camera comprises a housing 1 including an opening through which access can be gained to a film compartment, the opening being closable by means of a cover 3. The film compartment includes a pair of chambers 1 C adapted to accommodate a film cartridge and a take-up spool, or a roll film spool and a further spool, respectively. A guide surface 1 b is provided between the chambers 1 C to guide the film from one compartment to the other. In the case where the camera is designed to receive a cassette of film, the chambers 1c are adapted to receive storage and take-up areas of the cassette respectively, and the guide surface 1 b is replaced by a support surface for a web portion of the cassette.

The cover 3 is hinged to the housing 1 by means of axle stubs 3c which are rotatably received in respective bearing bushes 1 a. At an end thereof remote from the axle stubs 3c, the cover 3 has a latch hook which can be engaged with a locking catch 2 made of resilient plastics material to retain the cover in a position wherein it closes the opening in the housing. The locking catch 2 is mounted between a side wall 16 of the housing 1 and an adjacent wall 1 fof one of the chambers 1 c, and has an operating button or knob 2a which extends through a hole 1 dformed in the side wall 1 e so that it projects only very slightly above the latter. The actual locking part of the catch 2 presents an inclined surface 2b towards the cover 3 and a steep abutment 2c towards the housing.The latch hook on the cover 3 similarly presents an inclined surface 3a towards the housing 1 and a steep abutment 3b towards the cover proper.

During closing of the cover 3, the inclined surfaces 3a and 2b slide past each other thus causing a slight pivotal movement of the catch 2 until the abutments 3b and 2c are firmly hooked together. For opening the cover 3, the operating button 2a is pressed inwards, thereby releasing the interlocking engagement of the abutments 2c and 3b. The operating button 2a projects just so far above the housing side wall 16 that a simple depression of the button 2a into the plane of this side wall will not be enough to release the interlocking engagement; for such release the button 2a must be depressed slightly further below this plane. This is a simple precaution designed to prevent accidental opening of the camera, for example in the event that it is accidentally dropped.

In the camera of the invention, the number of component parts of the cover 3, its manufacturing cost and its space requirement are reduced because the film pressure plate or the cassette applicator springs are omitted. More particularly, the cover 3 comprises a first region 4 which is substantially rigid and which defines a generally planar pressure surface extending over the film guide surface 1 b or the cassette support surface (as the case may be), and a pair of second regions 5 which are resiliently deformable and which extend in opposite directions from the first region 4. The cover is moulded in a single piece from plastics material, and more particularly the axle stubs 3c are formed integrally at an end of one of the regions 5, while the latch hook is formed integrally at an end of the other region 5.With a view to avoiding undue size and thickness of the plastics moulding which would make production of the cover by injection moulding somewhat problematical, the pressure surface in the region 4 is formed by a plurality of ribs 3dof equal height, which preferably extend parallel to the direction of film feed. However, these ribs may be of an alternative configuration: for example, they may take the form of a plurality of internesting rectangular frames.

Where the camera is adapted to take roll film provided in cartridges or on spools, the guide surface 1b conveniently has respective steps 1g above and below the longitudinal edge of the film so as to form a channel in which the film is received. The pressure surface formed by the ribs 3d on the cover can then bear on the surface of these steps lg, as shown in Figure 3. Parts 3e of the cover in the regions 5 are not only substantially thinner than the ribs 3d but they may also taper towards the marginal edge of the cover 3 in order to increase their elasticity. If desired, the outer regions 5 of the cover 3 may assume a concave form towards the film compartment.The elastic force generated by the inherent tension in the cover parts 3e when the cover 2loses the opening, as shown in full lines in Figure 1, is so strong that it applies the pressure surface to the film or to the steps 1g at a pressure corresponding to that which is normal in cameras.

Moreover, upon actuation of the operating button 2a, this elastic force causes the cover 3 automatically to snap slightly open, namely into the position shown in chain-dotted lines.

If the camera 1 is a miniature camera with rotatable sprocket wheels in the region of the film guide path, the ribs 3dmust be provided with suitable gaps or recesses 3f in those regions thereof which correspond to such sprocket wheels in order to allow proper engagement between the sprocket wheels and the film perforations.

In order to ensure light-proof closing of the cover 3 relative to the housing 1 , the inwardlydirected surface of the cover 3 is provided with a light-sealing ridge 3g which extends completely around the film compartment when the cover closes the opening in the housing. When the cover is closed, the ridge 3g engages in a corresponding groove 1h in the housing. In order to enable the light-sealing ridge 3g to enhance the rigidity of the cover 3 in the region 4 whilst not detracting too much from the elasticity of the lateral regions 5, the ridge 3g includes two sections which are spaced apart transversely of the film feed direction and which have a reduced separation in the region 4.The parts 3h of these two sections which have a reduced separation terminate approximately on the same straight lines as the extremities of the ribs 3d, thus providing along these straight lines pivot axes for the elastic cover regions 3e. For reasons connected with injection moulding technology, it is advisable to give the ribs 3d and 3g a trapezoidal profile.

If the camera is designed for use with film cassettes, the pressure surface formed by the ribs 3dwill not press against the film guide path 1 b, 1g but instead will press against the back of the cassette, and for this reason the thickness of the ribs 3d may be correspondingly reduced.

Embodiments other than that described above are conceivable. For example, it may be advantageous to arrange for the vertical dimension or height of the ribs 3dto decrease in a direction towards the stub axles 3c and/or the locking catch mechanism in corresponding manner to the curvature of the cover 3 itself.

Because the present invention eliminates the need for mounting cassette-applicator springs and/or a film pressure plate on the cover 3, there is achieved an economy in costs arising from the use of fewer parts and correspondingly less assembly work. In addition an economy in space requirement is also achieved which is by no means insignificant. Since the cover 3 has an integral pressure surface and elastic side parts 3e, it can have a considerably shallower depth dimension than a cover in which springs or a pressure plate must be mounted. Bearing in mind the ever increasing demand for smaller and slimmer cameras, therefore, the slimmer camera shape resulting from the use of a thinner rear cover according to this invention is a considerable advantage.

Claims (21)

Claims

1. A rear cover for a camera housing which includes a guide surface for a film and/or a support surface for a film cassette, the rear cover comprising a first region which is reinforced and which presents an integral, generally planar pressure surface to said guide or support surface, and resiliently deformable second regions which are formed integrally with the first region and which, when the cover is in a closed position on said housing, are resiliently deformed to urge the pressure surface towards said guide or support surface.

2. A camera comprising a housing having an opening therein through which access can be- gained to a film compartment, the film compartment including a guide surface for a film or a support surface for a film cassette, and a cover for closing the opening in the housing, the cover comprising a first region which is reinforced and which presents an integral, generally planar pressure surface to the guide or support surface, and resiliently deformable second regions which are formed integrally with the first region and which, when the cover closes said opening, are resiliently deformed to urge the pressure surface towards the guide or support surface.

3. A camera as claimed in Claim 2, wherein two second regions are provided on opposite sides of the first region, one of the second regions being provided with bearing elements whereby the cover is attached to the housing, the other second region being provided with locking elements whereby the cover can be retained in a position wherein it closes the opening.

4. A camera as claimed in Claim 3, wherein the thickness of the second regions decreases in a direction away from the first region and towards the bearing and locking elements, respectively.

5. A camera as claimed in Claim 3 or 4, wherein the pressure surface is formed by a plurality of ribs which project from a surface of the cover which faces the film compartment.

6. A camera as claimed in Claim 5, wherein the heights of the ribs decrease in a direction towards the bearing and locking elements, corresponding to the curvature of the cover.

7. A camera as claimed in any of Claims 2 to 6, wherein each of the second regions is slightly concave to the film compartment when the cover closes the opening in the housing.

8. A camera as claimed in Claim 2, wherein the pressure surface is formed by a plurality of ribs which project from a surface of the cover which faces the film compartment.

9. A camera as claimed in Claim 8, wherein the ribs are all of substantially the same height.

10. A camera as claimed in Claim 8 or 9, wherein the ribs are elongate and are disposed parallel to one another.

1 A camera as claimed in Claim 10, wherein the ribs are also parallel to the direction of film transport.

12. A camera as claimed in Claim 8 or 9, wherein the ribs are in the form of internesting rectangles.

13. A camera as claimed in any one of Claims 8 to 12, wherein the ribs are trapezoidal in crosssection.

14. A camera as claimed in any one of Claims 8 to 13, further comprising a rotatable sprocket wheel which is adapted to engage perforations in said film, and wherein the gap between adjacent ribs is increased in the vicinity of the sprocket wheel.

1 5. A camera as claimed in any one of Claims 2 to 14, further comprising a continuous lightsealing ridge which is provided on the cover and which engages in a corresponding groove in the housing when the cover closes said opening.

16. A camera as claimed in Claim 15, wherein the light-sealing ridge extends continuously around the film compartment when the cover closes the opening in the housing.

1 7. A camera as claimed in Claim 1 5 or 16, wherein the light-sealing ridge includes two sections which are spaced apart transversely of the direction of film transportation, the separation of the two sections being reduced in the region of the guide or support surface.

18. A camera as claimed in Claim 17, wherein the area where the separation of the two sections is reduced has substantially the same extent as the reinforced pressure surface with respect to the direction of film transportation, so that the second portions are able to flex about the boundary of the reinforced pressure surface.

19. A camera as claimed in any one of Claims 2 to 18, wherein the cover is moulded as a single piece from plastics material.

20. A rear cover for a camera housing, substantially as hereinbefore described with reference to the accompanying drawing.

21. A camera substantially as hereinbefore described with reference to the accompanying drawing.