US3212423A - Photographic shutter - Google Patents

Description

Oct. 19, 1965 F. SINGER ETAL PHOTOGRAPHIC SHUTTER 3 Sheets-Sheet 1 Filed April 22, 1963 1965 F. SINGER ELTAL. 3,212,423

PHOTOGRAPHIC SHUTTER Filed April 22, 1965 5 Sheets-Sheet 2 Fi Pi l/16m 5.2/0

Oct. 19, 1965 F. saws-5m .EEAL 12 9 PHOTOGRAPHIC SHUTTER Filed April 22, 1963 {5 Sheets-$heet 3 United States Patent 3,212,423 PHOTOGRAPHIC SHUTTER Franz Singer and Helmut Muller, Munich, Germany, as-

signors to Compur-Werk Gesellschaft mit beschriinkter Haftung & Company, Munich, Germany, a company of Germany Filed Apr. 22, 1963, Scr. No. 274,563 Claims priority, application Germany Apr. 27, 1962, C 26,858; June 25, 1962, C 27,310 Claims. (CI. 9563) The present invention relates to a photographic shutter and more specifically to the delay mechanism for con trolling the exposure period.

The present invention provides a delay mechanism which permits an infinite variable setting of the exposure period and which is adapted for use in cameras having the stop aperture and exposure period setting means coupled and controlled by an exposure meter.

According to the present invention there is provided a delay mechanism which is coupled to the main operating lever by means of a transmission lever. This transmission lever remains in a single starting position reg-ardless of the exposure period. The transmission lever is provided with an abutment surface which cooperates with a starting member of the delay mechanism. When the exposure period is varied, the position of the starting member with respect to the abutment surface is altered. The abutment surface of the transmission lever is disposed at right angles with respect to a plane passing through the setting axis of the starting member and the bearing axis of the transmission lever.

The delay mechanism includes a starting member in the form of a toothed segment which has the teeth in engagement with the next adjacent wheel of the delay mechanism. The starting member also has an operating pin which cooperates with the abutment surface on the transmission member. There is provided a setter plate which is pivotally mounted on the bearing pin for the above mentioned adjacent wheel of the delay mechanism. The pivot pin of the starting member is mounted on the setter plate and spring means is provided to maintain the starting member and the setter plate in engagement.

The pivot pin of the starting member has a control cam mounted thereon and the position of the control cam is set by the exposure setter. The spring means which maintains the starting member and the setter plate in engagement has one end thereof bearing against the shutter housing and urges the pivot pin of the starting member against the control cam of the exposure setter. Thus, this spring performs the dual function of insuring a positive engagement between the starting member and the setter plate and providing for a play-free engage ment between the control cam and pivot pin.

The mounting of the starting member of the delay mechanism is a particular feature of the present invention. The bearing of the starting member is on a pivot pin between the engagement of the pivot pin with the control cam of the exposure setter and the point of anchorage of the pin on the setter plate. Thus the starting member which has substantial force exerted thereon during the run down of the shutter is held between two stationary support points thereby preventing any rocking movement of the starting member. That portion of the pivot pin in contact with the control cam is preferably in the form of an eccentric and may be made of a plastic material so as to reduce friction between the parts.

An object of the present invention is to provide a photographic shutter with a delay mechanism having a transmission lever disposed between the main operating member of the camera and the starting member of the "ice delay means, the transmission lever remaining in a single starting position regardless of the exposure period.

Another object of the present invention is to provide a delay mechanism for a camera shutter with a starting member having a pin adapted to cooperate with an abutment surface on a transmission lever, the starting member being pivoted on a pin mounted on a setting plate wherein the setting plate is in turn pivotally mounted on the adjacent wheel of the delay mechanism.

Still another object of the present invention is to mount the starting member of the delay mechanism for a camera shutter on a pin having the ends thereof maintained stationary during rotation of the starting member.

Other objcets and many of the attendant advantages of the present invention will become more readily apparent upon consideration of the following detailed specification in connection with the accompanying drawings wherein:

FIGURE 1 shows a shutter in plain view and with the front plate removed,

FIGURE 2 is a cross section on the line IIII of FIGURE 1,

FIGURES 3 and 4 show details of the shutter according to FIGURE 1 in different operating positions,

FIGURE 5 is a view, partly in plan, of a further embodiment of the shutter, and

FIGURES 6 and 7 give plan views of another form of construction.

The shutter shown in FIGURE 1 is of the bladed type, well known in the art, the mechanisms being installed in a shutter housing 10. There are, for example, five shutter blades 12 which are pivoted at 12a in the shutter housing 10 and are operated by driving pins 14a of a blade operating ring 14 so as to perform a reciprocating movement for opening and closing the objective aperture of the camera. In turn the blade operating ring is moved by a main operating member 16 and a crank 18 which is pivotally coupled thereto and cooperates with the upwardly curved end of an arm 14]) of the shutter operating means. The main operating member 16 has a cocking spindle 16a, which projects rearwardly out of the shutter housing, and a driving spring 20 which urges the main operating member in the clockwise direction. In the cocked position, which is shown in FIGURE 1, the main operating member is arrested by a trip lever 22. When this lever is actuated, the main operating member 16 moves under the action of its spring from the cocked position seen in FIGURE 1 in the clockwise direction towards its rest position shown in FIGURE 3, this being determined by a stationary stop pin 24 against which the nose 16d of the main operating member abuts. During this run-down movement of the main operating member 16, which thereby transcribes an angular path of about 150, the crank 18 is first moved to the right, the crank web 18a thereof moving the arm 14b of the blade operating ring in the clockwise direction for the purpose of opening the shutter blades 12. In the second phase of this run-down movement of the main operating member, the crank 18 is moved to the left again, and during this movement the other crank web 18b thereof moves the arm 14b, and the shutter operating ring 14, in the counterclockwise direction to close the blades back into the rest erating ring 14. In fact the crank web 18a will slide, under the action of a spring 26, over and past the inner face of the arm 14b directed towards the centre of the shutter assembly, a further spring 28 anchored to the arm 14b of the shutter operating ring 14 holding the same in the rest position. During the second phase of the cocking movement the crank 13 moves to the left again until it resumes its position in accordance with FIGURE 1.

The control of the exposure period of a shutter by preventing a free run down movement of the main operating member of the shutter mechanism into the shutter-open position by means of a toothed geared delay mechanism is known in the art. The duration of the action of the delay mechanism on the main operating member, and consequently the duration of the exposure period is adjustable by a time setting ring incorporated in the shutter assembly. The geared delay mechanism of the shutter assembly described is, in accordance with the present invention, of the following construction:

A double armed transmission lever 32, which is mounted on a fixed pivot at 32a, is disposed between the main operating member 16 and the starting member 31 of the delay mechanism, this lever 32 being urged against a stop 36 by a weak spring 34, One arm of the transmission lever has an abutment surface 32b cooperating with the abutment surface 16b of the main operating member, while the other arm of the lever 32 has an abutment surface 32c which co-acts with an operating pin 30a of the starting member 30. The starting member comprises a toothed segment having the teeth thereof in mesh with an adjacent pinion wheel 38 of the delay mechanism, and this latter wheel drives a fly wheel 44 of large mass through toothed gear pinions 40 and 42. It is possible to replace the fly wheel with an escapement wheel having an anchor.

The toothed segment 30 has a boss 30b and this is mounted for free rotation on a pivot pin 46a, the pivot pin 46a being secured to a setting plate 46. This plate 46 is capable of being rocked about a fixed bearing pin 54 of the wheel 40 of the delay mechanism. A spring 48 is wound around the boss 36b and has one end 48a in engagement with the driving pin 30a while its other end 481) bears against the shutter housing Ill. By this means the driving pin 30a is positively engaged with a projection 461) of the setting plate 46. There is an eccentric 50 which is force fitted on the upper end of the pivot pin 46a and the spring 48 urges the eccentric 50 against the driving face 52 of a ring (not further shown) which regulates the exposure period and is rotatably mounted in a well known manner on the front of the shutter. When this setting ring is operated, the pivot pin 46a, and the setting plate 46 carrying the same, are pivoted about the pin 54 through the engagement of the driving face of the control cam 52 and the eccentric 50. The toothed segment or starting member 30, which is mounted on pin 46a secured to the setting plate 46, is rocked as a whole in the same direction about the pivot pin 54 and consequently the driving pin 30a thereof assumes a starting position appropriate to the chosen setting in relation to the abutment face 32c of the transmission lever 32. FIGURE 1 shows in full lines the position of the parts for maximum delay, that is to say set for a long exposure period, for example, & of a second, while the positions of the parts relatively to the abutment surface 32, when adjusted to the minimum exposure period of second, is indicated in broken lines, and only partially, in FIG- URE 1. It is clearly apparent from these two relative positions that the driving pin 30a is set very close to the abutment surface 320, which is in its starting position, where long exposure periods are desired while it gets further and further away from this abutment surface 320 for shorter and shorter exposure periods and approaches closer to the spindle 32a, whereby there is a variation of the transmission ratio between the parts 32 X and 30 in consequence of the variation of the length of lever arm represented by the distance between pins 32a and 30a. The abutment surface 32c must not be straight. In fact it canas illustrated-be slightly curved, so as to correct or achieve the requisite ratio in the torque transmission to the delay mechanism.

When a minimum exposure period is set, however, the driving pin 30a is adjusted outside the zone of traverse of the abutment surface 32c. In the first case, depicted in full lines, the delay mechanism is thus brought into operation after a shorter degree of angular travel of the transmission lever 32, whereas in the case of short exposure periods, it does not come into operation until later and with a varied transmission ratio. In the case of a minimum exposure period, further contrast, the delay mechanism does not come into operation at all because the transmission lever 32 only moves idly for this setting and does not contact pin 319a.

During the run-down movement of the main operating member 16, with the blades 12 in the open position the abutment surface 16b makes contact with the abutment surface 32b of the transmission lever 32, whereby the latter is carried along in the counterclockwise direction. In the setting position depicted in full lines in FIGURE 1, the abutment surface 320, after a short initiating movement, comes into contact with the pin 3% of the starting member 30. This member is now pivoted about the pivot pin 46a of the setting plate 46, which is now stationary, and against the action of the spring end 4801, and thereby sets the delay mechanism into operation. The run-down movement of the delay mechanism, and consequently the delay effect itself, lasts until the abutment surface 32b of the transmission lever 32 slips away from the abutment surface 16b of the main operating member 16 and the members 32 to 44 remain in the rundown position seen in FIGURE 4. Since the main operating member 16 is of circular shape at the portion of its periphery denoted 160, it can complete the end phase of its run-down movement, until it reaches the rest posi tion depicted in FIGURE 3, without any hindrance or obstruction.

The transmission lever 32 and all the remainder of the delay mechanism do not assume the rest or starting position as shown in FIGURE 1, under the action of the springs 34 and 48a respectively, until the edge of the abutment surface 32!) slides away from the peripheral portion 16c on cocking the main operating member 16.

The delay mechanism described above possesses the following inventive features.

(1) The transmission lever is disposed between the main operating lever 16 and the starting member 30 of the delay mechanism and is maintained constantly in a fixed starting position by the spring 34, having an abutment surface 320 which cooperates with the member 30.

(2) During the setting, the member 31] is adjustable, relatively to the stationary transmission lever 32, around a setting axis 54.

(3) The abutment surface 320 of the transmission lever 32 extends approximately perpendicularly to a plane which passes through the setting axis 54 of starting member 30 and the pivot axis 32a of the transmission lever 32..

The first of the features mentioned above involves the advantage that when the members 16 and 32 encounter one another the width of the surface 16b and 32b in engagement is very substantial. This area of engagement is, moreover, completely independent of the exposure time setting and is always of the same degree, because the parts 16, 32 always assume the same relative positions when the shutter is cocked, irrespective of whether a short or a long exposure period has been set. This large and constant impact area on abutment also ensures a low-friction and unrestricted transmission of force.

The use of the two other features of the invention enumerated above has. the advantage of affording provision for adjustment of the exposure periods over a large range of infinitely variable settings, allied with a very compact arrangement of the transmission members and the elements of the delay mechanism. The amount of force which is required for the setting is very small because, apart from the invevitable bearing friciton of the exposure period setter, only the resistance of the spring end 48b has to be overcome during this setting. It is possible, however, as will be explained in more detail later, to eliminate even the intervention of this spring action so as to produce an extremely low-friction and low-power setting potential such is very desirable in the case of shutters which are programme-controlled.

The spring 48 has the dual functions of bringing about the positive engagement of the parts 30a and 46b and at the same time ensuring a play-free application of the pivot pin 46a to the control cam 52 of the exposure time etter. In accordance with a special feature of the invention the eccentric 50, which directly engages the control cam 52 and is mounted on the pin 46a, is made of a plastic material and this substantially reduces the friction between the plastic portion 52 and the metallic ring which sets the exposure period. The eccentric itself is made of very large diameter so that it can be manipulated without difiiculty for adjustment to the correct position during assembly. This adjustment, which is required by variations in tolerance in the parts, can be carried out by small displacements of the eccentric 50 in relation to the pivot pin 46a by means of a setting key which can be inserted in the slot 50a at the top of the eccentric.

In addition it is pointed out that the toothed segment 30 has its boss 3% disposed partway along the pivot pin 46a, that is to say between the engagement areas of the parts 50 and 52, which are immovable during the operation of the delay mechanism, and the anchorage point of the pivot pin 46a on the setter plate 46, which is also not moved during the operation of the delay mechanism. As a result the toothed segment 30, which turns under a powerful driving effort, is supported during the run-down of the delay mechanism, on two externally located, stationary bearings. As a result there is a non-rocking and twist-free mounting of the toothed segment and consequently an efiicient torque transmission.

As previously stated, when set to the minimum exposure period, the delay mechanism does not come into action at all. Thus, the main driving member 16 only carries along the transmission lever 32 which, however, is only of small weight and is only biassed by a very weak return spring 34, whereby it has scarcely any obstructive effect on the run-down motion of the shutter parts at a setting of the minimum exposure period to V of a second.

FIGURE 5 shows a modification of the delay mechanism. Here again the spring 48' is wound in the same way around the pivot pin 46a, but has its end 48b supported not against the shutter housing 10, as in the first embodiment, but lying against the pivot 54 of the setter plate 46. As a consequence this spring does not apply the eccentric 50 to the cam 52, and the pivot pin 46a, 50 is disposed within a closed control slot 52' of the exposure time setter. The arrangement and operation of the remaining parts disclosed in this embodiment is the same as in the embodiment previously described.

The construction according to FIGURES 6 and 7 has the aim of providing, as a further development of the shutter construction disclosed above a means whereby the elements of the delay mechanism are restored immediately to their rest positions on termination of the delaying action. This is accomplished by the fact that the abutment surface for the transmission lever is adjoined by a cutaway for the purpose of breaking the engagement of the transmission member and the main operating member when the delay effect is terminated. This cutaway is of a depth such that it allows for a rocking of the transmission lever into its starting position on termination of the delay operation. By this simple means, achieved merely by the shaping of the parts and without the use of additional constructional elements, there is a considerable reduciton of the spring-induced pressure of the setting pin of the delay mechanism against the control cam of the exposure time setter, and consequently under the same running-down conditions of the delay mechanism the movements are secured quickly and with low power, which is a particularly desirable feature where there is automatic regulation.

In the case of a shutter assembly in which the shutter member cooperating with the transmission lever is formed by a main operating disc or member which runs down in one direction of rotation after the trip action, in accordance with a further feature of the invention a cam formation is provided on the periphery of the main operating disc or member, this being bounded at one side by a radial abutment surface which is effective during the delay operation, and at the other side by the cutaway for the transmission lever, which permits the engagement to be broken after the delay movement. In the case of shutter constructions including a main operating disc which is adapted to move in a direction opposite to that of the run-down for the cocking purposes, it is advantageous to provide the arm of the transmission lever which is adjacent this disc with an inclined surface which cooperates with the peripheral cam portion of the main operating disc for the purpose of rocking the transmission lever to one side from its rest position during the cocking action.

The main operating member 16 illustrated in FIG- URES 6 and 7, and here in the form of a disc, has a cam formation 16c at the periphery thereof, this being bounded at one side by the radial abutment surface 16b and at the other side by a cutaway 162. During the delay procedure the abutment surface 32b of the transmission lever 32 cooperates with the abutment surface 16b, whereas the cutaway 16e is adapted to allow the arm of the transmission lever 32, defined by an inclined surface 32d, to swing out freely shortly after the termination of the delay, under the effect of the spring 34, into the rest position of FIGURE 6, so as to undo the delay engagement of the parts 16 and 32.

Consequently the transmission lever 32, in the embodiment illustrated, only makes contact with the main operating disc 16 (rotating in the clockwise direction from the position of FIGURE 6 on tripping), during the delay-(engagement between 16a nd 32b) and for a succeeding short period of time (engagement between 16c and 32d). As soon as the cutaway 162 is then brought opposite the inclined surface 32d, the engagement is broken and the transmission lever 32 returns to its rest position independently of the main operating disc 16 which runs down for a further short period thereafter.

During the movement of the members from the rest position of FIGURE 7 to the cocked position of FIG- URE 6, the edge of the main operating disc 16 (which turns in the counterclockwise direction) defining a cutaway 16e is pressed temporarily against the inclined surface 32d of the transmission lever 32, so that this lever is temporarily rocked away from its rest position (determined by abutment 36) in the counterclockwise direction, but is returned to this rest position as soon as the circular zone of the periphery of the main operating disc 16 is brought opposite the inclined surface 32b.

It is, therefore, clear that the main operating disc 16 is in engagement vw'th the transmission lever 32 only during the delay phase and a for a very short period during the cocking movement. The engagement between these members is, however, broken both in the rest position and also in the cocked position. By this means, during this operational positioning of the setting pin 5, the spring 48 is pressed against the operating 52 of the time exposure setter only under the action of the lightly loaded spring 48, and this consequently ensures that the setter may be moved quickly and with low power requirements, as is desirable in the case of an automatic regulation of the exposure period through the agency of a photoelectric exposure meter.

Obviously many modifications and variations of the present invention are possible in light of the above teachings. What is claimed as new and is desired to be secured by Letters Patent is:

1. A photographic shutter comprising, in combination, shutter blades, means for opening and closing said blades, a transmission lever operative'ly associated with said opening and closing means, a delay mechanism including a starting member and a plurality of interengaged Wheels interconnected with said starting member, an operating pin on said starting member, an abutment sunface on said transmission lever adapted to contact said pin on rotation of said transmission lever, a .setting plate, a pin mounted on said setting plate, the starting member being journalled on said last named pin, means for pivotally mounting said setting plate whereby movement of said setting plate shifts the position of said starting member and the position of the operating pin relative to the abutment surface of the transmission lever to vary the exposure period.

2. A photographic shutter according to claim 1 wherein said means for pivotally mounting the setting plate comprises the mounting for the wheel in said delay mechanism adjacent the starting member.

3. A photographic shutter according to claim 1 including spring means for maintaining the starting member and setting plate in engagement.

4. A photographic shutter according to claim 3 including a control cam engaging the pivot pin of said starting member, said spring means urging the control cam and pivot pin into engagement.

5. A photographic shutter according to claim 1 including a control cam having a slot therein, the pivot pin of said starting member engaging said slot and spring means for retaining the setting plate and starting member in engagement.

6. A photographic shutter according to claim 1 including a control cam in engagement with the pivot pin of said starting member, the starting member being mounted on said pin between the engagement of the pin with the control cam and the mounting 'of the pin on the setting plate.

7. A photographic shutter comprising shutter blades, means for opening and closing said shutter blades,

means for delaying the closing of the shutter blades to vary the exposure period, said last named means including a pivotally mounted transmission member, said transmission member having an abutment surface thereon, a delay mechanism, said delay mechanism including a starting member and a plurality of interengaging Wheels, a setter plate, said setter plate being pivotally mounted on the mounting for the wheel adjacent the starting member, a pin on said setter plate, said starting member being journalled on said pin, an eccentric on the end of said pin, a control cam in engagement with said eccentric, said eccentric being made of a plastic material, an operating pin on said starting plate, said operating pin adapted to cooperate with the abutment surface of the transmission member, movement of the control cam shifting the position of the operating pin and varying period of engagement of the transmission member with the delay mechanism.

8. A photographic shutter according to claim 7 including a cutaway surface on said transmission member adjacent said abutment surface to permit disengagement of the operating pin and transmission member after termination of the delay whereby said transmission member is adapted to pivot to the starting position thereof.

9. A photographic shutter according to claim 7 wherein said means for opening and closing the shutter blades includes a main operating member having a projection adapted to cooperate with a projection on the transmission member, a cutaway surface adjacent the projection permitting the engagement of the operating member and transmission member to be broken after rotation of the transmission member.

10. A photographic shutter according to claim 9 wherein the main operating member rotates in one direction during run down of the shutter and in the opposite direction during cocking of the shutter, an inclined surface on said transmission member adjacent the projection thereof for permitting pivoting 0f the transmission member during cocking of the main operating member.

References Cited by the Examiner UNITED STATES PATENTS 3,089,401 5/63 Gebele -63 NORTON ANSHER, Primary Examiner.

JOHN M. HORAN, Examiner.

Claims (1)

1. A PHOTOGRAPHIC SHUTTER COMPRISING, IN COMBINATION, SHUTTER BLADES, MEANS FOR OPENING AND CLOSING SAID BLADES, A TRANSMISSION LEVER OPERATIVELY ASSOCIATED WITH SAID OPENING AND CLOSING MEANS, A DELAY MECHANISM INCLUDING A STARTING MEMBER AND A PLURALITY OF INTERENGAGED WHEELS INTERCONNECTED WITH SAID STARING MEMBER, AN OPERATING PIN ON SAID STARTING MEMBER, AN ABUTMENT SURFACE ON SID TRANSMISSION LEVER ADAPTED TO CONTACT SAID PIN ON ROTATION OF SID TRANSMISSION LEVER, A SETTING PLATE, A PIN MOUNTED ON SAID SETTING PLATE, THE STARTING MEMBER BEING JOURNALLED ON SAID LAST NAMED PIN, MEANS FOR PIVOTALLY MOUNTING SAID SETTING PLATE WHEREBY MOVEMENT OF SAID SETTING PLATE SHIFTS THE POSITION OF SAID STARTING MEMBER AND THE POSITION OF THE OPERATING PIN RELATIVE TO THE ABUTMENT SURFACE OF THE TRANSMISSION LEVER TO VARY THE EXPOSURE PERIOD.

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