US3744392A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focal plane shutter gap setting mechanism
Assignee: HASSELBLAD
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Filing: 1970-12-08
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Granted: 1973-07-10
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Expires: 1990-12-08
Abstract
Abstract An improved shutter assembly for a photographic camera with a focal plane shutter, such as a curtain-type or one with two plane disks separated by an adjustable gap, in which an opening means and a closing means are separated by an adjustable gap, means for cocking, locking and releasing the shutter are operatively connected with means for forming a preset gap and means for opening and closing the opening and closing means, respectively, are operatively connected to the opening and closing means. The preset gap width corresponds to the fastest shutter speed and at slower speeds an electromechanical or electronic delay means forms a larger gap.
Inventors
- 👤 L Dahlgren
- 👤 A Alfredsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:44
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/08; G03B9/28; G03B9/32; G03B9/34; G03B9/58
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
328 words
A focal plane shutter comprising first and second curtains mounted for bidirectional movement across a film gate between cocked and released shutter conditions respectively, said first and second curtains having free edges respectively which are disposed in overlapping relation to one another when said shutter is in its released condition, means for cocking said shutter comprising a first gear member selectively rotatable in a preselected direction to draw said first curtain from its released position toward its cocked position, a second gear member selectively rotatable to draw said second curtain from its released position toward its cocked position, drive means for rotating said first gear member in said preselected direction, coupling means between said first and second gear members responsive to rotation of said first gear member for effecting rotation of said second gear member thereby to cause both of said curtains to be drawn simultaneously from their released positions toward their cocked positions with the free edges of said curtains being maintained in said overlapping relation as said free edges move from the released positions of said curtains across said film gate toward the cocked positions of said curtains, said coupling means including a movable arm pivotally affixed to said second gear member, a cam disposed in fixed position adjacent said second gear member, and a cam follower mounted on said arm and engaging said cam, said cam and cam follower being operative to permit synchronous rotation of said first and second gear means until the overlapped free edges of said curtains have both moved completely across said film gate in a cocking direction whereafter said cam, operating through said cam follower, causes said arm to pivot relative to said second gear member so as to effect a differential movement between said first and second gear members to separate the free edges of said curtains from one another by an intervening gap of predetermined dimension corresponding to the fastest shutter speed as said cocking operation is completed.
Claim 2
Dependent Claim
328 words
A focal plane shutter comprising first and second curtains mounted for bidirectional movement across a film gate between cocked and released shutter conditions respectively, said first and second curtains having free edges respectively which are disposed in overlapping relation to one another when said shutter is in its released condition, means for cocking said shutter comprising a first gear member selectively rotatable in a preselected direction to draw said first curtain from its released position toward its cocked position, a second gear member selectively rotatable to draw said second curtain from its released position toward its cocked position, drive means for rotating said first gear member in said preselected direction, coupling means between said first and second gear members responsive to rotation of said first gear member for effecting rotation of said second gear member thereby to cause both of said curtains to be drawn simultaneously from their released positions toward their cocked positions with the free edges of said curtains being maintained in said overlapping relation as said free edges move from the released positions of said curtains across said film gate toward the cocked positions of said curtains, said coupling means including a movable arm pivotally affixed to said second gear member, a cam disposed in fixed position adjacent said second gear member, and a cam follower mounted on said arm and engaging said cam, said cam and cam follower being operative to permit synchronous rotation of said first and second gear means until the overlapped free edges of said curtains have both moved completely across said film gate in a cocking direction whereafter said cam, operating through said cam follower, causes said arm to pivot relative to said second gear member so as to effect a differential movement between said first and second gear members to separate the free edges of said curtains from one another by an intervening gap of predetermined dimension corresponding to the fastest shutter speed as said cocking operation is completed.
Claim 3
Dependent Claim
59 words
The structure of claim 1 including first and second locking means disposed adjacent said first and second gear means respectively for locking said first and second curtains into their cocked positions, and means for releasing said first and second locking means to permit movement of said curtains across said film gate from their cocked positions to their released positions.
Claim 4
Dependent Claim
12 words
The structure of claim 2 wherein said releasing means is electromagnetically operable.
Claim 5
Dependent Claim
67 words
The structure of claim 1 wherein said arm is pivotally mounted at one of its ends on said second gear member, the other end of said arm including a projection which extends toward said first gear member for engagement with a pin affixed to said first gear member, said cam follower comprising a further pin affixed to said arm and bearing on the surface of said cam.
Claim 6
Dependent Claim
29 words
The structure of claim 4 wherein said arm is angularly shaped, said further pin being affixed to said arm at a position between the two ends of said arm.
Claim 7
Dependent Claim
35 words
The structure of claim 4 wherein said second gear member includes a slot, said projection extending from said arm on one side of said second gear member through said slot toward said first gear member.
Claim 8
Dependent Claim
65 words
The structure of claim 1 wherein said cam includes a first substantially circular portion concentric with the axis of rotation of said second gear member and operative to permit said synchronous rotation of said first and second gear members, and a second outwardly sloping portion merging smoothly into said first portion and operative to effect said differential movement between said first and second gear members.
Claim 9
Dependent Claim
84 words
The structure of claim 1 wherein said first and second gear members are coaxial with one another, said drive means comprising a third gear member coaxial with said first and second members, a follower member extending from said third gear member toward said first gear member, a pin extending from said first gear member toward said third gear member for engagement by said follower member, and a fourth gear member in mesh engagement with said third gear member for rotating said third gear member.
Claim 10
Dependent Claim
50 words
The structure of claim 8 including means responsive to occurrence of predetermined relative rotational positions of said third and fourth gear members for selectively moving said follower member from a first position in which it may engage said pin to a second position in which no such engagement can occur.
Claim 11
Dependent Claim
17 words
The structure of claim 9 inclUding spring means for urging said follower member toward said first position.
Claim 12
Dependent Claim
29 words
The structure of claim 8 wherein the number of teeth on said third gear member comprises an integral multiple of the number of teeth on said fourth gear member.
Claim 13
Dependent Claim
40 words
The structure of claim 8 including locking means for selectively locking said first gear member into its cocked position, and a projection extending from said fourth gear member toward said locking means for controlling the operation of said locking means.
Claim 14
Dependent Claim
41 words
The structure of claim 12 including further locking means for selectively locking said second gear member into its cocked position, and means extending from one to the other of said locking means for coordinating the operations of said two locking means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |