US2759749A

US2759749A - Closure device for cameras and the like

Info

Publication number: US2759749A
Authority: US
Inventors: Takats Zoltan
Original assignee: General Aniline and Film Corp
Current assignee: GAF Chemicals Corp
Priority date: 1952-07-23
Filing date: 1952-07-23
Publication date: 1956-08-21
Anticipated expiration: 1973-08-21

Description

Aug. 21, 1956 2. TAKATS V CLOSURE DEVICE FOR CAMERAS AND THE LIKE Filed July 23, 1952 2' Sheets-Sheet 1 FIG. 2'

FIG. 1

FIG. 3

ATTORNEYS R O T WK m N m m Z g- 21, 1956 z. TAKATS 2,759,749

' CLOSURE DEVICE F OR CAMERAS AND THE LIKE Filed July 25, 1952 2 Sheets$heet 2 INVENTOR ZOLTAN TAKATS By KMW ATTORNEYS United States Patent CLOSURE DEVICE FOR CAMERAS AND THE LIKE Zoltan Takats, Vestal, N. Y., assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware Application July 23, 1952, Serial No. 300,537

4 Claims. (Cl. 292-241) This invention relates to closure devices, and more particularly to lock mechanisms, of the type which provide forcible closure as well as forcible separation of body members.

It is often necessary to provide'locking means between relatively movable and separable body members, for example, between the cover and the body portion of a box. In cases where the body portion and the cover have inter-engaging walls to form a tight seal, a conventional locking device will sufiice to prevent separation of these members, but has the disadvantage that when released these members must be forcibly separated by some other means. The tighter the fit between the members, the more difiicult their separation as well as their closure.

Tight fitting containers are necessary in various packagings such as paints or storage cans for volatile substances, etc. The present invention provides a simple closure mechanism which can be applied to various types of structures where it is desired to forcibly bring together relatively movable body members upon closure, and forcibly separate them to a certain extent upon opening.

The primary object of this invention is to provide a closure or lock mechanism which, aside from the functions of bringing together the separated bodies and then locking them in a fixed position, will upon opening separate such bodies to a predetermined extent.

Another object of this invention is to obtain the above recited functions in a simple manner by rotary motion, in one direction for closure and in the other direction for separation.

A particular feature of this invention is that the coercive action of the closure mechanism is obtained by cam members which operate simultaneously in both directions of motion.

As pointed out above, the closure mechanism, in accordance with this invention, has a variety of fields of application. An example of its specific use is in connection with photographic camera structures of the box type, where the camera body is in two parts which must fit tightly together yet must be easily separable by the user. This application of the invention has been chosen for illustration.

Other objects and advantages will be apparent from the following description of the invention pointed out in particularity in the appended claims, and taken in connection with the accompanying drawings, in which:

Figure 1 is a top view of the box portion of a camera showing the key elements of the male part of the closure mechanism;

Figure 2 is a sectional view thereof along lines 2-2;

Figure 3 is a bottom view thereof showing manual I actuating lever of the closure mechanism;

Figure 4 is a perspective view of the male member of the closure mechanism;

Figure 5 is a bottom view of the cover portion of the camera which telescopes into the box portion shown in Patented Aug. 21, 1956 Figure 1, showing the cam means or female portion of the closure mechanism;

Figure 6 is a side elevational view of this telescoping cover portion;

Figure 7 is an enlarged perspective view of the female portion of the lock mechanisms showing the concentric distribution of the cam surfaces;

Figure 8 is a perspective view of both members of the closure mechanism in open position; and

Figure 9 shows both members of the closure mechanism in closed position.

Referring to the drawings, in the various views of which identical reference characters denote the same or similar component elements, the camera consists of two interfitting body portions, namely, a casing 11 which forms an oblong box or shell and a cover portion comprising a frame member 12 (Figures 5 and 6) which fits into the casing 11 and carries a cover plate 13. The latter fits tightly over the edges of the casing walls to form a solid, light-tight assembly.

On the front side of the casing 11 is mounted the lens 14' supported in the shutter assembly 15 from which extends the shutter release lever 16. The method and means for mounting the lens and shutter assembly are particularly described in a copending application of John Dearstyne, Serial No. 258,329, filed November 27, 1951, now Patent No. 2,685,237 issued August 3, 1954.

The closure device, which is the subject matter of this invention, is also in two parts, designated as a male and female part which interengage to bring together the body portions of the camera when closed, and forcibly separate these portions when opened, as will hereinafter be described.

Essentially, the male member comprises a plurality of key elements 17 and 17', extending radially from a circular plate 18 supported on a shaft 19. The latter is slit so as to have resiliency and extends through a suitable aperture in the bottom wall 20 of the casing 11 which has a recessed portion 21 so as to accommodate a manual closure actuating lever 22 afiixed to the shaft 19, whereby the lever 22 is flush with the outside of the casing 11. The recessed portion 21 extends within the angular displacement necessary for the lever 22 to actuate the closure mechanism. The arrangement of the lever 22 within the recessed portion 21 is illustrated in Figure 3. It can be be seen that the two extreme portions of the lever 22 are designated with a letter C at one end and a letter O at the other end indicating closure and opening positions of the mechanism, respectively.

The other body portion of the camera comprises a frame member 12 so constructed as to provide a support for the film spools 25 and also hold the film in exposure position behind the lens 14 when inserted into the housing 11. Attached to the frame 12 is a cover plate 13 which has an inturned edge so as to fit tightly, overlapping the side walls of the casing 11.

The customary film winding knob 28 is mounted over a film spool winding shaft and extends through the cover plate 13. A view finder 29 may also be affixed to the cover plate.

The bottom plate 30 of the frame member 12 has a circular cut-out, the edges of which are flared out to form a plurality of concentrically arranged cam elements 31, corresponding to the number of sets of key elements 17 and 17' in the closure mechanism. The cam surfaces 31 extend outwardly in the direction of the bottom wall of the casing 11 so that when the frame member is inserted into the casing, the cam surfaces are facing the key elements of the closure device as will be further described.

Each cam element 31 has an outer cam surface 32 and an inner cam surface 33; the cam elements being distributed approximately 120 degrees apart. Between cam elements there is provideda radially extending slot 35 to permit the passage of the set of key elements of the male portion of the closure mechanism, which coacts with the lower cam surfaces 33.

The function of the lock mechanism may best be understood with reference to Figures 8 and 9, which show the physical relationship of the closure members in both the open and closed positions and the engagement of the key elements with the cam surfaces.

As seen in Figure 8, the two members of the closure mechanism are aligned facing each other. In the camera, which is taken as an example for a practical use of the closure mechanism, this occurs when the frame member 12 is inserted into the casing 11. The bottom wall 20 of the casing '11 and the bottom plate 39 of the frame 12 represent two relatively movable bodyportions Which are about to be forcibly brought together to effect closure of the camera.

It is seen that one set of key elements 17, which extends above the other set of key elements 17 passes through the cut-out portions 35 so that the radially extending, bent back'portions of the keys, will, upon moving the lever 22, turn and engage the inner surfaces 33 of the cam segments 31. Each key element 17 will engage the inner cam surface 33 of its complementary cam segment and when the male member of the closure device is turned by the lever 22 in counterclockwise direction, the key elements 17' Will be constrained to follow the slope of their complementary cam segments; whereby the bottom plate 13 (i. e. the frame 12) and the bottom wall 20 (i. e. the casing 11) are forcibly brought together and so held, until the lever 22 is moved in the opposite direction. The force exerted by the closure pulls the cover plate 13 over the edges of the walls of the casing 11 resulting in a tight closure between the two portions of the camera.

It is to benoted that'in closing, the active members of the closure device are the keys 17 and the cam surfaces 33. At the same time, the keys 17 will also follow the outer cam surfaces 32 of the cam segments 31 but no force is developed during this motion. Now, when the lever 22 is turned clockwise, the active role between the sets of key elements becomes reversed and the lower set, representing the keys 17, will be constrained to follow the slope of the outer cam surfaces 32. The action is' simultaneous as to the two sets of

key elements

17 and 17 so that there is no lost motion but incremental rotary displacement of the key elements will effect movement of the body members in one direction or the other depending upon the direction of rotation of these elements. The force so produced causes separation of the two tightly held portions of the camera. The distance of separation is determined by the extension of the cam segments in the axial direction of movement of the body members. This may more conveniently be termed as the height of the cam segments.

Referring to Figure 9, the closed position shows the key elements 17' fully in mesh with the inner cam surfaces 33 and the key elements 17 near the beginning of the slope of the outer cam surfaces 32 ready to be engaged thereby when the lever 22 is turned in clockwise direction.

The present closure mechanism provides for dual action with simple inter-engaging cam means and key elements concentrically arranged in a unitary structure. In practice, 3 cam segments with a corresponding dual set of keys, each containing three "key elements, proved very satisfactory for smooth locking and opening of a box type photographic camera. In other applications, which can be for a variety of purposes, a greater number of cam segments may be used. The slope of the cams will determine the total distance of separation and the ease of lever action and movement of the body portions.

I claim:

1. A closure device for relatively movable body members which are forcibly brought together upon closure and forcibly separated from each other upon opening, comprising cam means concentrically arranged upon one body member and extending in the direction of relative movement of said members, said cam means having a plurality of inner and outer sloping surfaces; a rotatable lacy element ai'fixed to the other of said body member, said key element having two sets of concentrically arranged complementary surfaccs the surfaces of one set being laterally displaced above the other, one set of which upon rotation engages said inner sloping surfaces and the other set simultaneously engages said outer sloping surfaces and being constrained thereby to move said body members toward each other upon incremental rotation of said key element in one direction, and to move said body members away from each other upon similar rotation of said key element in the other direction.

2. A closure device for relatively movable body members which are forcibly brought together upon closure and forcibly separated from each other upon opening, comprising cam means concentrically arranged-upon one body member and extending in the direction of relative movement of said members, said cam means having a plurality of inner and outer sloping surfaces; a rotatable key element affixed to the other of said body member, said key element having two sets of concentrically arranged complementary surfaces, the surfaces of one set being laterally displaced above the other, the lower set of which upon rotation engages said inner sloping surfaces and the higher set simultaneously engages said outer cam surfaces and being constrained thereby to move said body members toward each other upon incremental rotation of said key element in one direction, and to move said body members away from each other upon similar rotation of said key element in the other direction.

3. A closure device for relatively movable body members which are forcibly brought together upon closure and forcibly separated from each other upon opening, comprising a cam element having three concentrically disposed cam segments upon one body member and extending in the direction of relative movement of said body members, each said segments having inner and outer sloping surfaces; a rotatable key element affixed to the other of said body member; said key element consisting of two sets of radially extending fingers having sloping surfaces complementary to said cam segments one set of said fingers being displaced laterally above the other, said first set upon rotation engaging said inner cam surfaces, and the other set of said fingers simultaneously engaging said outer cam surfaces, said fingers being constrained thereby to move said body members toward each other upon incremental rotation of said key element in one direction, and to move said body members away from each other upon similar rotation of said key element in the other direction.

4. A closure device in accordance with claim 3, wherein said segments are bent out of a base plate and separated by radially extending slots through which the key elements engaging the inner cam surfaces may pass.

References Cited in the file of this patent UNITED STATES PATENTS 947,185 McBean Jan. 18, 1910 1,201,714 Frantz Oct. 17, 1916 2,281,443 Jones Apr. 28, 1942