GB2230615A

GB2230615A - Camera shutter mechanism

Info

Publication number: GB2230615A
Application number: GB8908019A
Authority: GB
Inventors: Yet Chan
Original assignee: Achiever Ind Ltd
Current assignee: Achiever Ind Ltd
Priority date: 1989-04-10
Filing date: 1989-04-10
Publication date: 1990-10-24
Anticipated expiration: 2009-04-10
Also published as: CN2075791U; GB8908019D0; GB2230615B

Abstract

A camera shutter cocking and release mechanism comprises a bifurcate member (22) arranged to pivot in a horizontal plane, one of said member arms (23) extending into the path of travel of transport sprocket holes of the film, a bell crank member (29) mounted for pivotal movement generally in the plane of movement of the bifurcate member (23) and biassed into a rest position, the other arm (34) of the bifurcate member (22) acting upon one end (33) of the bell crank (29), the other end (32) of the bell crank (29) cooperating with a pawl (28) provided on a shutter plate (26), the bell crank (29) being provided with an upstanding latch (35) and a spring-biassed latching member (36) arranged to cooperate with the latch (35) and to be moved away from a latching position by operation of a shutter release button (39). <IMAGE>

Description

CAMERA This invention relates to a camera and to a mechanism for a camera According to the present invention there is provided a camera mechanism for a camera, which mechanism includes a shutter aperture, a spring-biassed shutter plate, a film winder, a shutter cocking mechanism adapted to be operated by transport sprocket holes in the film, and a shutter release mechanism, the shutter cocking mechanism comprising a bifurcate member arranged to pivot in a plane perpendicular to the plane of a film in the camera, one of said arms extending into the path of travel of transport sprocket holes of the film, a bell crank member mounted for pivotal movement generally in the plane of movement of the bifurcate member and biassed into a rest position, the other arm of the bifurcate member acting upon one end of the bell crank, the other end of the bell crank cooperating with a pawl provided on the shutter plate, the bell crank being provided with an upstanding latch and d spring-biassed latching member arranged to cooperate with the latch and to be moved away from a latching position by operation of a shutter release button, the arrangement being such when film is transported through the camera by use of the film winder, said first arm of said bifurcate member will engage and move with the film thus to move the said second arm of said bifurcate member and so cause pivotal movement of the bell crank which will cause the said other end of said bell crank to move into a cocking position with respect to the pawl of the shutter plate and to be latched into a cocked position by co-action between the latch and the latching member and such that operating the shutter release button disengages the latch and latching member causing the bell crank to return to its rest position, in doing so momentarily contacting the pawl of the shutter plate so as momentarily to open the shutter aperture.

Preferably the mechanism includes means for preventing continued winding on of the film after the bell crank has moved to its cocking position. This may conveniently be achieved by arranging that a projection on the latching member engages a gear coupled to the film winder when the latching member moves into a latching position.

The invention also provides a camera which includes a camera mechanism as hereinbefore defined.

An embodiment of a camera according to the present invention will now be described by reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of the camera and its component parts; and Figures 2A, 2B & 2C, 3A, 3B & 3C and 4A, 4B & 4C are respectively diagrammatic plans and front elevations of the mechanism at different positions.

Referring to the drawings, a camera comprises a front body 1 and a rear body 2 and a mechanism housing 3. The front body 1 has an aperture 4 for allowing light to pass therethrough, and carries a view finder 5 and a film winder 6, which winder includes a gear 7 and a film cartridge engaging member 8.

The mechanism housing 3 is essentially in the form of a box having an open rear and a front closed by a lens support plate 9 carrying a lens 10. Mounted on an upper surface of housing 3 is a number of upstanding pins 11, 12, 13, 14, 15, 16, 17 and 18 whose purpose will become apparent hereinafter. The housing also has a hole 19 for receiving the film winder 6.

Pin 11 receives and supports a spring arm 20 which acts as a pawl with gear 7 so that the film winder can rotate in one direction only. Pin 12 receives and supports for rotation a gear wheel 21 which is engaged with gear 7. A bifurcate member 22 is mounted for sliding and pivotal movement about pin 13.

Arm 23 of bifurcate member 22 extends rearwardly of the housing 3 and into the plane of a film 43 of a "126" film cartridge to be fitted into the camera, so as to engage with transport sprocket holes in a said film. A spring 24 extending between a pin 25 of bifurcate member 22 and pin 14 biasses bifurcate member 22 rearwards of the housing 3 and in a clockwise direction (Figures 2B, 3B and 4B).

An upstanding pin 44 is formed in a recess 45 in the upper surface of the housing 3, which pin 44 is co-operable with a depending pin 46 of the bifurcate member 22, as hereinafter described.

A shutter plate 26 is pivotally mounted on pin 27 and is biassed into a shut position with respect to lens 10 by a spring 26'. Shutter plate 26 includes a pawl 28 which extends above the plane of said upper surface of housing 3.

A bell crank 29 is mounted for pivotal movement about pin 15. Bell crank 29 is biassed in a counter-clockwise direction (with reference to Figures 2A, 3A and 4A) by a spring 30 extending between an upstanding pin 31 on bell crank 29 and pin 16.

One end 32 of bell crank 29 is arranged to coact with pawl 28 of shutter plate 26. The other end 33 of bell crank 29 coacts with the other arm 34 of bifurcate member 22.

Bell crank 29 also includes an upstanding latch pin 35.

A latching member 36 is arranged for pivotal movement on pin 17 and is biassed to the front of housing 3 by a spring 37 extending between a pin 38 on latching member 36 and pin 18.

A spring-biassed shutter release button 39 includes a projection 40 arranged to bear upon a pin 41 of latching member 36.

Latching member 36 also includes, at its distal end, a pin 42 which can move into the path of teeth of gear wheel 21, and a shoulder 36 for in use engaging with latch pin 35 of bell crank 29.

The operation of the camera will now be described by reference to Figures 2, 3 and 4.

When film winder 6 is rotated, film 43 is drawn to the left in Figure 2. This causes arm 23 of bifurcate member 22 also to move to the left because the arm 23 is received in a transportation sprocket hole in said film 43. This in turn causes arm 34 of bifurcate member 22 to move the end 33 of bell crank 29 in a clockwise direction which causes end 32 of bell crank 29 to pass beyond pawl 28. Thereafter latch pin 35 engages with shoulder 36' of latching member 36 so that bell crank 29 is maintained in a cocked position. When latching member 36 is in its latching position it is moved forwardly so that pin 42 meshes with gear wheel 21 and prevents further rotation of film winder 6.

When the bifurcate member 22 is pivoted by the film 43, the depending pin 46 passes round the upstanding pin 44 of the housing 3 before the bifurcate member 22 is slid forward by, and clear of, the film 43. The bifurcate member 22 is thereby prevented from disengaging from the film 43 until it is sufficiently pivoted, so as to ensure that the bell crank 29 reaches the cocked position.

When the shutter release button 39 is pressed, projection 40 of the shutter button 39 is moved rearwardly and bears upon pin 41 of latching member 36 thereby to disengage the latching member 36 from bell crank 29. This disengagement causes the bell crank 29 to rotate in a counter-clockwise direction under the influence of spring 30 which causes end 32 of bell crank 29 to strike and pass beyond pawl 28 of shutter plate 26 thereby momentarily to pivot the shutter plate 26 and to allow light to pass into housing 3 and to impinge upon film 43.

The invention provides a small cheap and convenient camera.

The invention may be performed otherewise that as has been described and all modifications, changes and variations that would be apparent to one skilled in the art are encompassed within the present invention.

Claims

1. A camera mechanism for a camera, which mechanism includes a shutter aperture, a spring-biassed shutter plate, a film winder, a shutter cocking mechanism adapted to be operated by transport sprocket holes in the film, and a shutter release mechanism, the shutter cocking mechanism comprising a bifurcate member arranged to pivot in a plane perpendicular to the plane of a film in the camera, one of said arms extending into the path of travel of transport sprocket holes of the film, a bell crank member mounted for pivotal movement generally in the plane of movement of the bifurcate member and biassed into a rest position, the other arm of the bifurcate member acting upon one end of the bell crank, the other end of the bell crank cooperating with a pawl provided on the shutter plate, the bell crank being provided with an upstanding latch and a spring-biassed latching member arranged to cooperate with the latch and to be moved away from a latching position by operation of a shutter release button, the arrangement being such when film is transported through the camera by use of the film winder, said first arm of said bifurcate member will engage and move with the film thus to move the said second arm of said bifurcate member and so cause pivotal movement of the bell crank which will cause the said other end of said bell crank to move into a cocking position with respect to the pawl of the shutter plate and to be latched into a cocked position by co-action between the latch and the latching member and such that operating the shutter release button disengages the latch and latching member causing the bell crank to return to its rest position, in doing so momentarily contacting the pawl of the shutter plate so as momentarily to open the shutter aperture.

2. A camera mechanism according to claim 1, which includes means for preventing continued winding on of the film after the bell crank has moved to its cocking position.

3. A camera mechanism according to claim 2, wherein a projection on the latching member engages a gear coupled to the film winder when the latching member moves into a latching position.

4. A camera mechanism according to any one of claims 1 to 3, wherein means are provided for preventing the bifurcate member from disengaging from a said film before the bell crank reaches the cocked position.

5. A camera mechanism, substantially as hereinbefore described.

6. A camera which includes a camera mechanism as claimed in any one of claims 1 to 5.

7. The features hereinbefore disclosed, or their equivalents, in any novel selection.