US3270448A - Apparatus comprising a timing mechanism and an intermittent switching mechanism - Google Patents

Description

Sept. 6, 1966 w. HOLZER 3,270,448

APPARATUS COMPRISING A TIMING MECHANISM AND AN INTERMITTENT SWITCHING MECHANISM Filed March 29, 1965 Fig.2.

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ATTORNEYS ,sitates a re-selection of different time intervals.

United States Patent APPARATUS COMPRISING A TIMING MECHA- NISM AND AN INTERMITTENT SWITCHING MECHANISM Walter Holzer, Drosteweg 19, Meersburg (Bodensee),

Uberlingen (Bodensee), Baden, Germany Filed Mar. 29, 1965, Ser. No. 443,590 4 Claims. (CI. 40-78) This is a continuation-in-part of applicants co-pending application Serial No. 167,715, filed January 22, 1962, now Patent No. 3,210,487, issued October 5, 1965.

The invention relates to apparatus for automatically changing transparencies in projectors.

It is an object of the invention to construct the apparatus in such a way that it is robust, shockproof, substantially unaitected by voltage fluctuations, compact and cheap to manufacture.

An apparatus comprising a timing and intermittent switching mechanism is known for progressively advancing a programme indexing disc, but which can be used for washing machines only and which is not suited for changing pictures in projectors.

A known automatic control system for projectors and stereoscopes comprises a spring-actuated mechanism for a. wheel and locking device, wherein an electric magnet and armature are provided for the locking action. Neither a motor controlling the timing mechanism nor another motor for the step-by-step system are present. The timing must be very exact, so it will operate in synchronism with the clockwork over the whole range. This neces- It also calls for timing of a lighting current circuit, wherein the second-hand touches a contact.

Another known device for controlling electric circuits is in the form of a punched card timing system, but in which there is no possibility of intermittent operation of a switch to change pictures, wherein the timing mechanism as well as the intermittent switching mechanism always start at the initial position.

For allocation of a series of still pictures to the text of a record, there has been proposed a device comprising a punched tape and contacts penetrating through the perforations for timing. With such a system the time sequence is initially convertibly fixed. This is also true of other, already known devices for projection of educational and/ or entertaining programmes, having a recording tape with metal foils for switching.

There are also projectors for automatically showing a series of transparencies. The projection times however cannot be adjusted but are dependent upon the uniform rotation time of a drum, carrying the transparencies. Special switches for showing the picture any length of time have to be actuated, and preselection of desired and variable time intervals during projection is not possible.

The use of a known circuit-opening and -closing switch, which is actuated during a certain setting-time on the still-picture projector does not make it possible to cause the picture sequence in a preselected time interval relation, .and to keep the mechanism so simple as to attain the different time intervals starting from an initial position.

The aim of the invention is therefore to avoid these disadvantages and to provide a simple device with which it is possible to change the pictures in projectors by means of a timing mechanism and an intermittent switching mechanism.

This object is attained by providing a device for changing pictures in a still-picture projector having adjust- 3,270,448 Patented Sept. 6, 1966 ice able time intervals, comprising a timingand intermittent switching mechanism, each of which has a slide connected to a disc and which is coaxially driven by means of a hollow shaft, the slide engaging at least two of three contact tracks on a printed circuit, one of which is in the form of segments, wherein the quick rotating slide of the intermittent switching mechanism is being moved after actuation of one of several selector contacts and the timing mechanism slide which either stands still or rotates slowly is taken over, from the initial position, by means of an overrunning clutch and carried back to the initial position, whereby according to the invention the timing mechanism and intermittent switching mechanism could be driven by the same motor, having a sliding rotor, which drives by means of several gears in one position, i.e. at a low energizing current the slide of the timing mechanism and in another position, i.e. high energizing current the slide of the intermittent switching mechanism.

This arrangement is cheap to manufacture and easy to adjust, while having great accuracy. Since the timing mechanism slide, as well as the intermittent switching mechanism slide start at their initial positions during the change of pictures, no errors are added up by stepwise operation. It is therefore sufiicient, for very precise operation, to arrange the switching segments at certain distances from one another, i.e. in form of conducting tracks on a printed circuit.

The driving motor could be a synchronous motor for practical purposes. The time elapsing, until the timing mechanism slide, starting from its initial position, engages the segment connected with the activated selector contact, is equal to the time interval during which the subsequent transportation [of the pictures is performed.

When the timing mechanism slide engages this selector contact, the rotor will be transported to the other engaging position, whereby the intermittent switching mechanism slide will be moved. The latter is faster than the timing mechanism slide and carries it along, until the intermittent switching mechanism slide reaches its initial position. At this point the timing mechanism slide is able to overtake the slide of the intermittent switching mechanism, until it reaches its initial position. The cycle can then start again.

The arrangement and general application of the drive motor are described in my Patent 3,041,480 (filed March 22, 1960, Ser. No. 16,789) and 3,164,729 (filed March 16-, 1960, Ser. No. 15,389).

The selector contacts enable the projectionist to set the time during which each individual picture is screened, by operating one or the other of the selector keys. The various selector keys correspond to various time intervals in the picture changing. It is desirable to provide the selector contacts in form of pushbutton keys, having an operating position, and upon further depression a rest position.

When the operating position is used, the picture changes are performed during the time associated with the particular selector key. When the rest position is used, a multiple of the time associated with this key is obtained.

In order to permit fully automatic screening, one possibility for the selector key consists in scanning a punched card, rotated by the intermittent switching mechanism. The card has recesses made by hand, in accordance with the desired programme and allocates therefore a predetermined time interval for screening of each picture. The operating sequence is then fully automatic. The pictures can be shown in conjunction with, for example, a tape recorder so that the pictures may be explained.

V Construction is further simplified, if the drive mot-or carries the ventilator wings as well as the projection lamp, thereby simultaneously cooling the projecting lamp, setting the time interval and effecting the intermittent switching.

If a printed circuit is used, the whole apparatus can be small and cheap to manufacture and the resulting accuracy and variety of possible combinations are such as are otherwise found only in much more expensive apparatus.

In order to permit alteration of the programme sequence, it is imporant for the motor driving the switching mechanism to drive the latter by means of a slip clutch, so that the shaft of the intermittent switching mechanism can be turned manually.

For fully automatic projection a recording tape containing the accompanying text with metal foils constituting the selector contacts or actuating same may be used so that the change of pictures necessarily coincides wit-h the sequence of the accompanying text instead of the punched card.

An example of the invention is illustrated in the drawing wherein:

FIGURE 1 shows the electric circuit of an apparatus according to the invention.

FIGURE 2 shows a portion of the operating mechanism.

FIGURE 3 shows a schematic view on a reduced scale of the over-riding clutch shown in FIGURE 2.

According to FIGURES 1 and 2 the timingand intermittent switching mechanism comprise three tracks on a printed circuit. The first of these tracks is closed, the second is interrupted and the third is made up of switch segments. The spacings of these switch segments correspond to the selected time intervals between picture changes. An router slide is moved by the timing mechanism and establishes the electric connection between the third and second contact tracks. An inner slide is moved by the intermittent switching mechanism and establishes the electric connection between the first and second contact tracks. An overriding clutch between the two slides enables the slide that is moved more slowly by the timing mechanism to be carried along by the faster slide, which is moved by the intermittent switching mechanism. It is carried along, until the slide moved by the switching mechanism, reaches .an interruption in the second contact track and remains stationary, until it is carried along next, while the slide moved by the timing mechanism runs on continuously.

FIGURE 1 shows the first contact track 1, having a connecting lug 2. The second contact track 3 has an interruption 4 in the form of a depression, as to avoid burning at the beginning and the end of this track. The first and second tracks 1 and 3 are bridged by a slide 5 mounted on a disc 6 (FIGURE 2). Any type of rotating arm can be used instead of a disc. The disc 6 is rigidly connected with the spindle 7.

The third contact track 8 is made up of the segments 29, 9, 10, 11, which are connected in that sequence to the second contact track 3 by a slide 112. The slide 12 is mounted on a disc 13 which is driven by the gearwheel 14 through a hollow shaft 47 surrounding the spindle 7. The main terminals 15, 16, and the drive motor 30 are also shown, as Well as the selector cont- acts 32, 33, 34, 35 which may be actuated manually or by the intermittent switching mechanism.

The drive motor 30 receives according to the illustrated example, after actuation of switch 50 current through resistor 21. With a low exciting current, the rotor 17 remains in the lower position, so that the gear 31 meshes with gear 14 to drive the timing mechanism by the slide 12.

When the drive motor 30 receives the full amount of current across the main terminals 16 and 19, the stator will be highly excited and the rotor 17 will be drawn dicated schematically.

into the stator field, assisted by the spring 51. The gear 36 then meshes with gear 39, causing actuation of the picture changing mechanism, and also with gear 38, which is rigidly connected to the spindle 7 and Will rapidly move slide 5.

The actual picture changing mechanism is only in- It comprises a gear wheel 39, crank and thrust rods 40, 41.

These are reciprocated in the direction of the arrow 42 depending upon the ratio of the gearing 39. They are provided with supports 43, 44 on which the pictures or transparencies 45 rest. Each picture drops in a known manner vertically to the plane of the drawing when the thrust rods 40, 41 with their supports are moved appropriately, and the next picture 45 may follow from above. This apparatus may be constructed in any other usual way.

The presence of the slip coupling 36.permits the spindle 7 to be turned by hand, by using the diagrammatically illustrated handwheel 46. According to the drawing the drive motor 30 also drives the fan above it for the projecting lamp (not shown).

It is to be mentioned that actuation of the selector contacts 32-35 is also possible by the gearing 39, if the sildes are to be fully automatic. The possibility of shaping the selector contacts 32-35 as scanning contacts of a magnetic tape onto which the contact-making foils are stuck, is not illustrated.

It is important for the continuously rotating drive motor 30, after actuation of switch 50 to use as little current as possible in its normal position, ie while driving the timing mechanism, with minimal loss of heat. High output is only required during the short time while driving the intermittent switching and picture changing mechanisms. A slip clutch 36 assists the fast, andsmooth meshing of gear 36 with gears 38- and 39, whereby full output of the drive motor will be permitted without danger of great wear.

The described apparatus functions as follows:

In the position shown, the slide 5 connects the first contact track 1 to the second contact track 3. The drive motor 30 thereby receives after actuating switch 50, full current, namely from the main terminal 15 through connecting strip 19, the second contact track 3, the slide 5, the first contacting track 1, the connecting lug 2, as well as the connecting strip 18 on one hand and through the main terminal 16 on the other hand. The drive motor 30 simultaneously drives the slide 6 as well as the picture changing mechanism. The slide 5, respectively the disc 6 move thereby in the direction of arrow 28 and overtake disc 13, while recess 48 on the disc 6 carries along with it the lever 26 on the disc 13 and thus also the slide 12. The functioning of this overrunning clutch is to be seen in FIGURE 3. It is a slip clutch, because if disc 13 moves in the direction of the arrow 28 relative to disc 6, then the rounded-off edge 49 of disc 6 prevents it from being carried along by disc 13.

When the slide 5 reaches the position 25, shown in dotted lines, then the drive motor 30 is almost de-energized, since the slide 12 has also broken the bridging of resistance 21. The rotor 17 again drives the timing mechanism and the spindle 7 stops rotating. The thrust rods actuated by the intermittent switching mechanism also stop in a corresponding position. In this position the picture is supported in the projector and screened until the slide 12 connects the next actuated selector contact across the corresponding contact segment through the main terminal 15. In relation to the time interval between picture changing, the position 27 shown in dotted lines is designated as the starting position of slide 12. This position is only temporary as can be seen from the preceding.

Depending on which of'the selector contacts 32 to 35 is closed, the terminal 15 is connected to the corresponding segment 9, 10, 11, 29 of the third contact track 8. The time taken by the slide 12, to pass from the dotted-line position 27 to the appropriate live contact segment designates the time interval bettween picture changes. In FIGURE 1 the selector contact 33 is closed, for example by hand. When the slide 12 reaches the position shown in full lines (FIG. 1), the drive motor 30 receives full current from the main terminal 15 through the second contact track 3, the slide 12, the contact segment 10, the contact 33 and the connecting strips 18 and 20 on one hand, as well as the main terminal 16 on the other hand. Thus the rotor 17 meshes with the gears 38 and 39. Now the picture changing mechanism is actuated and simultaneously the slide 5 which is mechanically connected to disc 6, will be moved in the direction of the arrow 2-8. The dotted-line position of the slide 5 in FIG. 1 indicates this position. As soon as slide 5 reaches contact track 3, shown in full lines, after leaving gap 4, the fast moving slide 5 carries inert slide 12 with it. The slide 5 is left in the gap 4, as it has switched itself ofl. after leaving contact track 3. The rotor 17 again drives the timing mechanism. The slide 12 now overtakes slide 5 and the entire process repeats itself.

If none of the selector contacts 3235 are closed, slide 12 rotates continuously, without the rotor 17 being changed to drive the intermittent switching mechanism.

The time taken by the slide 12 to reach one of the energised segments of the contact track 8, from the dottedline position 27 represents the time intervals at which the pictures are changed. The selector contact 32 for instance, gives a longer time interval for changing pictures than the selector contact 34.

Instead of the four segments 9-11 and :29 shown, any desired number of additional segments and associated selector contacts may be provided. The drive reductions from drive motor 30 to spindle 7 and gear 14 respectively, may be chosen at will. The overriding clutch may also be differently constructed.

The possibility to provide the stator of the drive motor with two or more windings or a tap winding resulting in different drive positions of the rotor, by means of different magnetisation is also of importance. In this case the priming resistance 21 and thus any direct connection between connecting strips 19 and 20 are eliminated. 4

The connecting lug 2 is properly connected to the winding or part of the winding respectively, which effects the strongest magnetization, while the contact segments are to be connected across the appropriate selector contacts to the less magnetizing winding or windings.

I claim:

1. Drive mechanism for a picture-changing slide projector With adjustable time intervals comprising a timing mechanism having a slide slowly driven by gearing and carried by a rotating par-t, while contacting with an interrupted contact track on a printed circuit and with another contact track comprising conductive contact-segments on the same printed circuit, an intermittent switching mechanism having a rapidly rotating driving connection to a coaxially mounted, rotating part carrying a slide which slides on said interrupted contact track and on a circular track, both of which are conductive, a one-way slip clutch for mechanically connecting the rotating parts With each other during rotation and for electrically connecting them with the segments and with switches, a picture-changing mechanism having a crank and thrust rods, and a motor the rotor of which in one position drives through a gear the rotating part of the intermittent switching mechanism and also the picture-changing mechanism and in another position through gears the rotating part of the timing mechanism.

2. The apparatus according to claim 1, wherein the motor drives the timing mechanism at a low magnetization of its stator.-

3. The apparatus according to claim 1, wherein the rotor is connected to a gear through the slip clutch.

4. The apparatus of claim 2, wherein the rotor is connected to a gear through the slip clutch.

References Cited by the Examiner UNITED STATES PATENTS 2,905,239 9/1959 Dietz ZOO-37 X 2,999,425 9/ 1961 Emmel 40-79 X 3,003,997 10/ 1961 Jennings 20037 X 3,015,251 1/ 1962 Pollan 40-79 X 3,151,257 9/1964 Anderson 20036 X 3,210,487 10/1965 Holzer 20036 JEROME SCHNALL, Primary Examiner.

EUGENE R. CAPOZIO, Examiner.

W. GRI'E'B, Assistant Examiner.

Claims (1)

1. DRIVE MECHANISM FOR A PICTURE-CHANGING SLIDE PROJECTOR WITH ADJUSTABLE TIME INTERVALS COMPRISING A TIMING MECHANISM HAVING A SLIDE SLOWLY DRIVEN BY GEARING AND CARRIED BY A ROTATING PART, WHILE CONTACTING WITH AN INTERRUPTED CONTACT TRACK ON A PRINTED CIRCUIT AND WITH ANOTHER CONTACT TRACK COMPRISING CONDUCTIVE CONTACT-SEGMENTS ON THE SAME PRINTED CIRCUIT, AN INTERMITTENT SWITCHING MECHANISM HAVING A RAPIDLY ROTATING DRIVING CONNECTION TO A COAXIALLY MOUNTED, ROTATING PART CARRYING A SLIDE WHICH SLIDES ON SAID INTERRUPTED CONTACT TRACK AND ON A CIRCULAR TRACK, BOTH OF WHICH ARE CONDUCTIVE, A ONE-WAY SLIP CLUTCH FOR MECHANICALLY CONNECTING THE ROTATING PARTS WITH EACH OTHER DURING ROTATION AND FOR ELECTRICALLY CONNECTING THEM WITH THE SEGMENTS AND WITH SWITCHES, A PICTURE-CHANGING MECHANISM HAVING A CRANK AND THRUST RODS, AND A MOTOR THE ROTOR OF WHICH IN ONE POSITION DRIVES THROUGH A GEAR THE ROTATING PART OF THE INTERMITTENT SWITCHING MECHANISM AND ALSO THE PICTURE-CHANGING MECHANISM AND IN ANOTHER POSITION THROUGH GEARS THE ROTATING PART OF THE TIMING MECHANISM.

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