US3430945A - Sheet feeding apparatus - Google Patents

Description

March 4, 1969 R. WICK ET SHEET FEEDING APPARATUS Sheet Filed April 5, 1967 IN V EN TORS l RICHARD WICK WOLFGANG KWIATKOWS Kl HELMU'L SCHAUSBERGER March 4, 1969 WICK ET AL 3,430,945

SHEET FEEDING APPARATUS Filed April 5, 1967 Sheet 6 of z Fig.2

IN V EN TOR5'.

RIC HARD WlCK WOLFGANG KWIATKOWSKI HELMUT SCHAUSBERGE R United States Patent 3,430,945 SHEET FEEDING APPARATUS Richard Wick, Grunwaltl, Wolfgang Kwiatkowski, Unterhaching, and Helmut Schausberger, Munich, Germany, assignors to Agfa-Gevaert Aktiengesellschaft, Leverkusen, Germany Filed Apr. 3, 1967, Ser. No. 627,934 Claims priority, application Germany, Apr. 29, 1966,

7 US. Cl. 271-42 6 Claims Int. Cl. B65h 3/24 ABSTRACT OF THE DISCLOSURE A sheet feeding apparatus wherein a pusher reciprocates in front of a back support for stacked sheets to advence the sheets into the housing of a developing machine during movement from a retracted to an extended position. The speed of the pusher is limited, at least during travel to extended position, to prevent uncontrolled displacement of sheets with reference to each other and particularly to ensure that the sheets come to a halt at the very instant when the pusher completes its forward stroke to extended position. The speed limiting means may comprise an air brake and/or a motor-driven power train which can advance the pusher from the retracted to extended and back to retracted position in response to a single revolution of an output shaft.

Cross-reference to related application A machine which can utilize the sheet feeding apparatus of our present invention is disclosed in the copending application Ser. No. 580,763 of Harold Fengler et al., filed Sept. 20, 1966-, now Patent No. 3,396,964, and assigned to the same assignee.

Background of the invention The present invention relates to an apparatus which can be utilized to feed individual or stacked sheets, plates or like commodities into the housing of a film developing machine or the like. More particularly, the invention relates to an apparatus which is especially suited for feeding stacks of exposed films into the range of an automatic conveying device in the housing of a developing machine. The conveying device normally includes a suction cup which moves between a sheet receiving and a sheet delivering position, and it is important to feed sheets into the range of the suction cup in such a way that the latter can invariably engage successive sheets irrespective of their size and irrespective of the speed at which the sheets are being advanced into the housing of the developing machine.

The aforementioned application Ser. No. 580,763 discloses a developing machine which is equipped with a sheet feeding apparatus including a pusher adapted to be reciprocated by hand and to thereby transfer stacks of accurately aligned exposed films into the range of a suction cup. Such sheet feeding apparatus has been found to be quite satisfactory. The stack of exposed films is inserted in a darkroom and is transferred into a dark chamber defined by the housing of the developing machine. Problems will arise if the operator is inexperienced and operates the pusher at an excessive speed so that the sheets will be propelled into the housing of the developing machine and beyond the range of the suction cup. This can happen if the sheets are relatively small, i.e., if they are not as wide as the widest sheets which are to be treated in the machine.

Accordingly, it is an important object of the present invention to provide a sheet feeding apparatus which is constructed and assembled in such a way that the member of members which transfer a stack of sheets into the range of a suction cup or another suitable conveying device cannot be operated at an excessive speed and wherein the exact speed at which the sheets are being transferred can be determined in advance and with a desired degree of accuracy.

Another object of the invention is to provide a sheet feeding apparatus of the just outlined character which can be combined with or incorporated in existing developing machines for exposed film or the like.

A further object of the invention is to provide a novel speed regulating unit for use in the improved sheet feeding apparatus and to construct and assemble the speed regulating unit in such a way that it can regulate the speed of transfer members during the return stroke and/or during the forward stroke of such members.

An additional object of the invention is to provide a sheet feeding apparatus which can be operated by hand or automatically and wherein the member or members which actually engage and transfer sheets into the range of a conveying device are held against excessive movement at least while they push or otherwise transfer one or more sheets from a first position to a second position so that each sheet comes to a halt as soon as the for-ward progress of the transfer member or members is arrested.

Summary of the invention One feature of the present invention resides in the provision of an apparatus for feeding stacked sheets, individual sheets or plates of exposed film or the like into developing or analogous machines. The apparatus comprises a back support which is preferably slightly inclined with reference to a vertical plane and is arranged to carry a supply of sheets, e.g., a stack of overlapping exposed films, a pusher which is reciprocably mounted on the back support and is movable between retracted and extended positions to advance the sheets along and beyond the back support during movement to extended position, and speed regulating means for limiting the speed of movement of the pusher, at least while the pusher moves toward the extended position.

The speed regulating or limiting means can include a simple air brake, especially if the pusher is reciprocated by hand. The air brake may include a fixed cylinder having a throttling orifice and a piston whose piston rod is connected with the pusher and expels air through the throttling orifice when the pusher moves toward extended position.

Alternatively, or in addition to the air brake, the speed regulating means may include a prime mover whose output shaft rotates in a single direction, and a power train which connects the output shaft with the pusher in such a way that the pusher moves from retracted to extended and back to retracted position in response to unidirectional rotation of the output shaft.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved sheet feeding apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawmg.

Brief descrip/z'on. of the drawing FIG. 1 is a perspective view of a sheet feeding apparatus which embodies one form of our improved speed regulating means;

FIG. 2 is a front elevational view of the sheet feeding apparatus, with the back support for the sheets omitted;

FIG. 3 illustrates modified speed regulating means which can be utilized in the sheet feeding apparatus of our invention in addition to or as a substitute for the means shown in FIG. 2; and

FIG. 4 is an enlarged fragmentary sectional view as seen in the direction of arrows from the line IVIV of FIG. 2.

Description of the preferred embodiment Referring first to FIG. 1, there is shown a sheet feeding apparatus 98 whose function is to transfer stacks of sheets 100 into a housing 101 mounted on the frame of and forming part of a developing machine 97. The exact details of the structure in the interior of the housing 101 and in the remainder of the developing machine 97 form no part of the present invention. Reference may be had to the aforementioned application Ser. No. 580,763 of Fengler et al. The invention is embodied in the sheet feeding apparatus 98, and more particularly in the construction, mounting and operation of a speed regulating unit for a sheet transfer member or pusher 104. This pusher 104 is located in front of a slightly inclined back support or panel 99 having at its front side horizontal grate bars 99a which abut against the foremost sheet 100. The panel 99 is installed on the frame of the developing machine 97 adjacent to a hingedly mounted gate 101a of the housing 101. The pusher 104 may be provided with an opening member which automatically opens the gate 101a when the pusher is caused to advance toward the housing 101.

The lower edge portion of the panel 99 is connected with a horizontal trough 103 which constitutes a guide for the lower end portion of the pusher 104 and simultaneously accommodates the lower edge portions of stacked sheets 100. The right-hand edge portions of the sheets 100 bear against suitably bent aligning members 1040 of the pusher 104 so that, when the stack is properly inserted into the channel of the trough 103 and its sheets 100 abut against the faces of the aligning members 1040, each such sheet overlaps exactly the adjoining sheet or sheets. The pusher 104 is further provided with a suitable handle 104k which can be grasped by hand in order to advance the pusher in a direction toward the gate 101a and to thereby transfer the sheets 100 into the interior of the housing 101. The upper end portion 104a of the pusher 104 (see FIG. 2) is slidable along a horizontal guide bar 102 whose ends are connected to the panel 99 and housing 101.

FIGS. 2 and 4 illustrate the details of a novel speed regulating unit for the pusher 104. Save for its upper end portion 104a, the pusher is indicated by broken lines, and FIG. 2 further shows the upper and lower guides 102, 103. The panel 99 and its horizontal grate bars 99a have been omitted for the sake of clarity. All component parts of the speed regulating unit are mounted on the rear side of the panel 99. These parts include an electric motor or an analogous prime mover 105 whose ouput shaft 105a is driven at a relatively low speed, for example, at about thirty revolutions per minute. It is also possible to utilize a prime mover which includes a high-speed electric motor and a step-down transmission whose output shaft replaces the output shaft 105a. The latter is connected with one end of a crank arm 106, the other end of which is articulately coupled to one end of a link 107. The other end of the link is articulately coupled to an extension or arm 108a provided on an oscillatable coupling member here shown as a disk 108 whOSe pivot 108b is mounted on the panel 99. When the motor 105 is started and rotates the output shaft 105a in a counterclockwise direction, the crank arm 106 causes the link 107 to oscillate the coupling member 108 back and forth about the axis of the pivot pin 10812. The pivot pin 1081) further supports one end of a second coupling member in the form of a lever 109 which is freely rotatable thereon and whose other end is articulately connected to a vertically reciprocable carriage 113 slidably mounted on a vertical guide rod 112 secured to the upper end portion 104a of the pusher 104 behind the panel 99. The numerals 110, 111 denote two balls which are mount ed in the coupling member 108 and are biased into shallow recesses or grooves (FIG. 4) in the adjoining face of the lower end portion of the lever 109. A spring biases the coupling member 108 axially toward the lever 109 and thereby urges the balls 110, 111 to remain in the associated recesses so that the lever 109 is normally compelled to share oscillatory movements of the coupling member 108. If the pusher 104 should jam or if the movement of the carriage 113 along the guide rod 112 is obstructed, the aforementioned spring yields and enables the coupling member 108 to oscillate independently of the lever 109. The balls 110, 111 are disposed diametrically opposite each other and at the same distance from the axis of the pivot pin 108b.

It will be readily understood that the motor can cause the pusher 104 to travel back and forth along the front side of the panel 99 when the balls 110, 111 compel the lever 109 to share oscillatory movements of the coupling member 108. The carriage 113 supports a downwardly extending actuating member or trip 115 which can displace the central contact 116a of an electric switch 116. When the carriage 113 assumes its lower end position, the trip 115 moves the central contact 116a away from its normal left-hand end position of engagement with the left-hand fixed contact 11611 and into engagement with a right-hand fixed contact 1160. This arrests the motor 105 for reasons which will be readily apparent by observing the electric circuit 118 which is shown in FIG. 2. If the operator grasps the handle 104b and moves the pusher 104 slightly away from its right-hand end position (which is the fully retracted position of the pusher), the guide rod 112 compels the carriage 113 to move upwardly and to lift the trip 115 whereby the central contact 116a of the switch 116 returns into current-conducting engagement with the left-hand fixed contact 116!) to thereby complete the circuit 118 of the motor 105. The motor rotates the output shaft 105a and the latter causes the lever 109 to move the carriage 113 upwardly and thereupon downwardly so that the trip 115 returns to the lower end position of FIG. 2 and opens the circuit 118 of the motor 105 in a fully automatic way. The pusher 104 comes to a halt in the fully retracted position, Thus, all the operator has to do is to set the pusher 104 in motion and the motor 105 takes over to complete the forward stroke (arrow 117) as well as the next-following return stroke of the pusher. The transmission ratio of the power train 106, 107, 108, 111, 109, 113, 112 is such that the forward stroke of the pusher 104 is carried out at an optimum speed which is not sutficient to effect excessive acceleration of sheets 100 so that the relative positions of sheets 100 remain unchanged at the time the pusher 104 begins its return stroke. This means that all of the sheets which have been transferred through the gate 101a and into the interior of the housing 101 come to rest in a desired position so as to be ready for further transfer in response to engagement by a suction cup which is fully described in the aforementioned application of Fengler et al.

In order to cause the pusher 104 to complete a full cycle including a forward stroke to extended position and a return stroke to retracted position, the output shaft 105a of the motor 105 must rotate the crank arm 106 through one full revolution. The motor 105 comes to a halt immediately when the pusher 104 returns to its fully retracted position. When the operator pushes the handle 104b in a direction toward the gate 101a, the balls 110, 111 might leave the respective recesses in the coupling member 108; however, such movement of the handle 10411 and pusher 104 causes the trip to release the central contact 116a and to start the motor 105. The motor then turns the coupling member 108 in a counterclockwise direction, as viewed in FIG. 2, and the member 108 catches up with the lever 109 so that the balls 110, 111 reenter their recesses and the lever 9 begins to turn with the coupling member 108.

The aforementioned spring, the balls 110, 111. and

the recesses of the coupling member 108 constitute a simple friction clutch which is effective to reciprocate the pusher 104 under normal operating conditions but will enable the coupling member 108 to turn independently of the lever 109 when the pusher 104 meets excessive resistance to forward or return movement or when the movement of carriage 113 and/or lever 109 is obstructed to the extent necessary to effect expulsion of balls 110, 111 from their respective recesses. If the lever 109 meets an excessive resistance to turning in a counterclockwise direction, as viewed in FIG. 2, the coupling member 108 continues to turn, first in a counterclockwise direction and thereupon in a clockwise direction, whereby the balls 110, 111 reenter the recesses and cause the coupling member 108 to return the pusher 104 to its fully retracted position, it being assumed that the lever 109 was disengaged from the coupling member 108 in an intermediate position somewhere between the fully retracted and fully extended positions of the pusher 104.

FIG. 3 illustrates a second speed regulating unit which can be used in addition to or as a substitute for the speed regulating unit of FIG. 2. This second unit constitutes an air brake and operates not unlike a conventional bicycle pump. It includes an elongated cylinder 120 provided in or on the housing 101 to receive a piston 119 provided at one end of an elongated piston rod 118 the other end of which is connected with the upper end portion 104a of the pusher 104. That end of the cylinder 120 which is remote from the pusher 104 is provided with a throttling orifice 121 but the other end of the cylinder 120 is fully open.

When the pusher 104 is advanced slowly in a direction toward the housing 101, the piston 119 expels air from the cylinder 120 and such air escapes through the throttling orifice 121. The resistance which the piston 119 encounters depends on the forward speed of the pusher 104, i.e., the resistance rises with a rise in forward speed and the cross-sectional area of the orifice 121 can be readily selected in such a way that the forward speed of the pusher 104 cannot exceed a predetermined maximum value, namely, a speed which could cause the sheets 100 travelling in front of the pusher 104 to move away from contact with the aligning members 1040 while the pusher performs a forward stroke. The maximum permissible forward speed of the pusher 104 is preferably selected in such a way that the aligning members 1040 will remain in contact with the smallest sheets 100 which are to be treated in the developing machine 97.

The air offers little or no resistance to return movement of the pusher 104 because the right-hand end of the cylinder 120 is preferably fully open, i.e., the crosssectional area of the opening or orifice at the right-hand end of the cylinder 120 exceeds at least slightly the crosssectional area of the throttling orifice 121.

A very important advantage of the speed regulating unit which is shown in FIG. 3 is that it can be assembled of simple and inexpensive parts and can be readily installed in presently known sheet feeding apparatus. As stated before, the unit of FIG. 3 can be used in addition to or as a simplified substitute for the speed regulating unit of FIG. 2.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivarence of the claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. Apparatus for feeding stacked or individual sheets of exposed film or the like into developing or analogous machines, comprising a back support arranged to carry a supply of sheets; a transfer member reciprocably mounted on said back support and movable between retracted and extended positions to advance the sheets along and beyond said back support during movement to extended position; and speed regulating means for limiting the speed of movement of said transfer member at least while the transfer member moves toward said extended position, said speed regulating means comprising a prime mover having a rotary output member and a power train connecting said output member with said transfer member and arranged to move said transfer member from retracted to extended and back to retracted position in response to one revolution of said output member.

2. Apparatus for feeding stacked or individual sheets of exposed film or the like into developing or analogous machines, comprising a back support arranged to carry a supply of sheets; a transfer member reciprocably mounted on said back support and movable between re tracted and extended positions to advance the sheets along and beyond said back support during movement to extended position; and speed regulating means for limiting the speed of movement of said transfer member at least while the transfer member moves toward said extended position, said speed regulating means comprising a prime mover having a rotary output member and a power train connecting said output member with said transfer member to move the latter from retracted to extended and back to retracted position in response to rotation of said output member, said prime mover comprising an electric motor, an electric circuit for said motor and normally closed switch means in said circuit, said power train including actuating means arranged to open said switch means and to thereby arrest said motor in retracted position of said transfer member.

3. Apparatus for feeding stacked or individual sheets of exposed film or the like into developing or analogous machines, comprising a back support arranged to carry a supply of sheets; a transfer member reciprocably mounted on said back support and movable between retracted and extended positions to advance the sheets along and beyond said back support during movement to extended position; and speed regulating means for limiting the speed of movement of said transfer member at least while the transfer member moves toward said extended position, said speed regulating means comprising a prime mover having a rotary output member and a power train connecting said output member with said transfer member to effect movement of said transfer member from retracted to extended and back to retracted position in response to unidirectional rotation of said output member, said power train comprising a pair of relatively movable coupling members and detent means yieldably connecting said coupling members so that one of said coupling members can move independently of the other coupling member when said transfer member meets excessive resistance to movement to one of said positions.

4. Apparatus as defined in claim 3, wherein one of said coupling members is constituted by a disk oscillatable about a fixed axis in response to rotation of said output member and the other coupling member comprises a lever which is rotatable about said fixed axis, said detent means comprising at least one spring-biased ball carried by one of said coupling members and normally extending into a recess provided in the other coupling member.

5. Apparatus for feeding stacked or individual sheets of exposed film or the like into developing or analogous machines, comprising a back support arranged to carry a supply of sheets and being slightly inclined with reference to a vertical plane; a transfer member reciprocably mounted on said back support and movable in a substantially horizontal path between retracted and extended positions to advance the sheets along and beyond said back support during movement to extended position, said back support comprising a trough extending in parallelism with the path of movement of said transfer member and arranged to receive the lower edges of sheets placed onto said back support in retracted position of said transfer member; and speed regulating means for limiting the speed of movement of said transfer member at least while the transfer member moves toward said extended position.

6. Apparatus for feeding stacked or individual sheets of exposed film or the like into developing or analogous machines, comprising a back support arranged to carry a supply of sheets; a transfer member reciprocably mounted on said back support and movable in a substantially horizontal path between retracted and extended positions to advance the sheets along and beyond said back support during movement to extended position, said back 8 support being provided with guide means for said transfer member; and speed regulating means for limiting the speed of movement of said transfer member at least while the transfer member moves toward said extended position, said speed regulating means being mounted at least in part on said back support.

References Cited UNITED STATES PATENTS 2,754,731 7/1956 Shields 27143 RICHARD E. AEGERTER, Primary Examiner.

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