Description:
BACKGROUND OF THE INVENTION
This invention generally relates to a cartridge for housing photographic film and more particularly relates to a cartridge for housing a coiled roll of photographic film, such cartridge including an improved cover latch.
Various containers have been heretofore described for housing a coiled filmstrip. The filmstrip is generally stored in a rolled form and played out through a port defined by the cartridge. To facilitate convenient loading of the cartridge and permit interchange of filmstrips, the housing is open-ended and includes a hinged access cover. In use, the cover is unlatched and rotated about its hinge thus allowing the user to conveniently insert a rolled filmstrip. After loading, the cover is snapped shut and the cartridge loaded into the projector.
For reasons of economy such cartridges are generally of unitary construction and molded of plastic. The fastening arrangement between the cover and the cartridge body is formed as an integral part of the cartridge. This construction requires relatively close tolerances between the mating components to assure a secure closure of the cover. A particular problem with a molded cartridge is that, during storage and use, the body tends to warp increasing the tolerances between the mating parts. As a result of such warping, there is a tendency for the cover to accidently open thus releasing the filmstrip. As previously mentioned the film is stored in a coiled condition. In the coiled condition, the film exerts a pressure upon the inner walls of the cartridge tending to urge the cover open thus aggravating the problem.
It is a main object of this invention to provide a film cartridge including an improved latch which permits convenient access to the interior of the cartridge. Other objects and advantages of this invention will be apparent from the description of the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a full perspective view of a cartridge including certain features of this invention;
FIG. 2 is a full side-view of the cartridge illustrated in FIG. 1 with the cover closed;
FIG. 3 is a full frontal view of the cartridge illustrated in FIG. 1 with the cover closed;
FIG. 4 is an enlarged fragmentary view of FIG. 2 with a portion of the cartridge removed for clarity of illustration; and
FIG. 5 is an enlarged fragmentary view of a portion of the cartridge illustrated in FIG. 1 taken along the line 5--5.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
HOUSING
With particular respect to FIG. 1, the illustrated cartridge 10 is preferably molded of plastic and includes an open ended housing 12 suitable for retaining a coiled roll of photographic film (not shown) and a cover 14 hinged to the housing 12 and serving to partially obstruct the cartridge opening 16. The cover 14 is secured to the housing 12 by a latching means 18 which will hereinafter be more thoroughly described. The housing 12 includes a cylindrical shaped rear wall 20 which merges into a relatively flat upper wall 22. The upper wall 22 terminates at the opening of the housing forming an upper edge 24. The lower end of the rear wall 20 merges into a substantially flat bottom wall 26 which also terminates at the opening forming a lower edge 28. The cover 14 is secured by a `living-hinge` 30 to the lower edge 28. Spaced from and formed integral with the bottom wall 26 the rear wall 20 and the upper wall 22 are a pair of film guide rails 32 which commence slightly forward of the lower edge 28 and terminate at the upper edge 24 of the top wall 22. The guide rails 32 serve to support the film along the margins thereof so as to prevent scratching of the surface of the film against the walls of the container 10 as the film is played out from the cartridge housing 12.
Additionally, the cartridge includes a pair of side walls 34 and 36 which are molded integral with the rear 20 bottom 26 and top 22 walls and which respectively define arcuate edges 38 and 40 at the opening of the housing 12. Formed with the side walls 34 and 36 and outwardly disposed are a pair of cartridge support guides 50, which serve to align the cartridge in a projector (not shown). each edge 38, 40 of the side walls 34 and 36 is angled inwardly for a short distance commencing at the upper edge 24 and terminating at an upper cup-shaped recess 42. The upper recess 42 is formed in the outwardly disposed surface of the side walls 34 and 36. Spacially positioned below the upper recess 42 are lower recesses 44 similarly shaped and defined by the outer surface of the side walls 34, 36. Each of the recesses 42, 44 is oriented opposite a similar recess in the opposite side wall. Each wall includes a projection 46 which extends outwardly from the general contour of the edges 38, 40 of the respective side walls 34, 36, and is positioned between a pair of recesses 42, 44. The inner surface of each projection 46 is formed to define an arcuate channel 48 which is inwardly disposed so that the channels 48 in each of the projections 46 are in registration. The cup-shaped recesses as well as the channels 48 of each of the side walls 34 and 36 cooperate with mating components in the cover to comprise the cover latching means 18.
COVER
The cover 14 is in the shape of a T with the base thereof hinged to the edge 28 of the bottom wall 26. As illustrated in the preferred embodiment, the cartridge 10 is molded of plastic with the hinge 30 being in the form of a thin plastic membrane which is frequently termed a "living hinge". This constructional feature provides an economical hinge which may be subjected to considerable flexure. The cover 14 is curved to conform to the curvature of the edges 38 and 40 of the side walls 34 and 36. With particular reference to FIG. 5, each of the ends 52, 54 of the cover define a pair of locking lugs or ears 56, 58. Each of the ears is arcuately shaped and projects normal to the cover towards the cartridge as illustrated in FIG. 1. Further, each locking ear is positioned for cooperative engagement with a respective cup-shaped recess 42, 44 defined by the outer surfaces of the side walls 34, 36. Disposed between each pair of the ears is a locking flange 60, 62 which is arcuate in shape and formed to snap snugly into the channel 48 defined by the projections 46 of the side walls. An elongated boss 64, 66 is formed on the inner surface of both ends 52, 54 of the cover. Each boss 64, 66 is oriented parallel to the base of the cover and spaced from a pair of locking ears, so as to provide grooves 68, 70. The width of the groove is slightly greater than the thickness of the side wall at the cup-shaped recess thereof allowing the walls 34, 36 to seat in their respective grooves 68. 70.
OPERATION
In use, a coiled photographic filmstrip (not shown) is placed within the cartridge 10 and allowed to expand under its own bias until the edges of the film ride along the rails 22. The outer end of the film convolution is positioned adjacent the upper edge 24 of the top wall 22 and the cover 14 is swung about its hinge 30 until the locking ears 56, 58 are aligned with their respective recesses 42, 44. In this position the cover 14 is forced toward the housing 12 until the locking flanges 60, 62 snap into their respective channels 48 and the cover 14 attains the position illustrated in FIG. 2. In this position, the housing 12 and the cover 14 form a securely locked unitary assembly. The top of the cover terminates at approximately the upper edge of the upper cup-shaped recesses 42, thereby defining a film play out port 72 adjacent the upper edge 24 of the top wall 22 facilitating play out of the film from the cartridge 10.
As illustrated in FIG. 3, when the cover 14 is in its closed position, a pair of spaced access ports 74 are defined which permit entrance of the projector sprocket wheels (not shown) into the cartridge for engagement with the film. The locking-ears 56, 58 which rest in the cup-shaped recesses 42, 44 as well as the locking grooves 68, 70 defined by the inner surface of the cover 14 force the outer walls 34, 36 into a predetermined relationship, thus assuring that each locking flange 60, 62 securely snaps into its respective channels 48. Should the side walls 34, 36 become warped through storage or use, the locking ears 56, 58, in co-operation with the locking flanges 60, 62, will draw the walls into their predetermined position so as to assure a positive lock between the cover 14 and the housing 12.
Although one embodiment of the invention is shown and described it will be apparent that various changes and modifications may be made and it is intended in the following claims to cover all such modifications and changes as may fall within the spirit and scope of this invention.