SHEET INTERMITTENT FEED DEVICE
United States Patent 3873014
A device comprising at least one electromagnet and a sheet feed member made of a ferromagnetic material disposed in spaced juxtaposed relationship across a path of movement of a sheet. The electromagnet is intermittently excited so that the sheet feed member intermittently moves relative to the electromagnet or the electromagnet intermittently moves relative to the sheet feed member whereby the sheet can be intermittently fed along its path of movement.
US Patent References:
Card advancing mechanism for serial punch
Hunter - October 1966 - 3276774
Electromechanical bi-directional motion actuator device
Sawyer - January 1968 - 3361948
Electromagnetic stepping device
Danilewicz et al. - July 1968 - 3391289
HYDRAULIC CONTROLLER FOR STRIP MATERIAL FEEDER
Aylesworth - June 1973 - 3741458
Card advancing mechanism for serial punch
Hunter - October 1966 - 3276774
Electromechanical bi-directional motion actuator device
Sawyer - January 1968 - 3361948
Electromagnetic stepping device
Danilewicz et al. - July 1968 - 3391289
HYDRAULIC CONTROLLER FOR STRIP MATERIAL FEEDER
Aylesworth - June 1973 - 3741458
Application Number:
05/375808
Publication Date:
03/25/1975
Filing Date:
07/02/1973
View Patent Images:
Export Citation:
Assignee:
Ricoh Co., Ltd. (Tokyo, JA)
Primary Class:
Other Classes:
271/267, 226/93, 226/150, 310/12, 271/266
International Classes:
B65H5/10; G06K13/077; B65H5/08; G06K13/02; B65H5/10; B65H17/36
Field of Search:
226/150,93,162 271/18.1,18.2,193,42,266,267,268,269,84,85 310/12
Primary Examiner:
Schacher, Richard A.
Assistant Examiner:
Stoner Jr., Bruce H.
Attorney, Agent or Firm:
Cooper, Dunham, Clark, Griffin & Moran
Claims:
What is claimed is
1. A sheet intermittent feed device comprising:
2. A device as defined in claim 1, wherein said returning means comprises means acting on said first member for resiliently biasing said first member toward said first position along said path.
3. A device as defined in claim 2, wherein said biasing means comprises an element fixed relative to said path, and a spring acting between said first member and said fixed element, and further including stop means for arresting movement of said first member, under the force of said biasing means, at said first position.
4. A device as defined in claim 3, wherein said second member comprises an electromagnet having two poles facing and spaced along said path; wherein said first member comprises a ferromagnetic member having two openings respectively positioned for register with said two poles when said first member is in said first position, and two solid portions respectively positioned on the sides of said two openings toward said first position; and further including a fixed plate extending over the path of movement of said first member; said fixed element being secured to said plate, and said stop comprising a portion of said plate projecting into the path of movement of said first member at said first position.
5. A device as defined in claim 1, wherein said second member comprises an electromagnet.
6. A device as defined in claim 5, wherein said returning means comprises a second electromagnet disposed adjacent said first position on the same side of the path as said first member and energizable for return of said first member to said first position upon de-energization of said second member.
7. A device as defined in claim 1, further including brake means disposed adjacent said path beyond said second position, said brake means comprising an electromagnetic element and a ferromagnetic element positioned on opposite sides of said path, one of the last-mentioned elements being movable toward the other upon energization of said electromagnetic element, for pressing and arresting sheet material in the path.
8. A device as defined in claim 1, wherein said path-defining means comprises plural supports spaced along the path for engaging said one major surface of sheet material therein.
9. A device as defined in claim 1, wherein said path-defining means comprises a nonmagnetic plate interposed between said second member and said path.
1. A sheet intermittent feed device comprising:
2. A device as defined in claim 1, wherein said returning means comprises means acting on said first member for resiliently biasing said first member toward said first position along said path.
3. A device as defined in claim 2, wherein said biasing means comprises an element fixed relative to said path, and a spring acting between said first member and said fixed element, and further including stop means for arresting movement of said first member, under the force of said biasing means, at said first position.
4. A device as defined in claim 3, wherein said second member comprises an electromagnet having two poles facing and spaced along said path; wherein said first member comprises a ferromagnetic member having two openings respectively positioned for register with said two poles when said first member is in said first position, and two solid portions respectively positioned on the sides of said two openings toward said first position; and further including a fixed plate extending over the path of movement of said first member; said fixed element being secured to said plate, and said stop comprising a portion of said plate projecting into the path of movement of said first member at said first position.
5. A device as defined in claim 1, wherein said second member comprises an electromagnet.
6. A device as defined in claim 5, wherein said returning means comprises a second electromagnet disposed adjacent said first position on the same side of the path as said first member and energizable for return of said first member to said first position upon de-energization of said second member.
7. A device as defined in claim 1, further including brake means disposed adjacent said path beyond said second position, said brake means comprising an electromagnetic element and a ferromagnetic element positioned on opposite sides of said path, one of the last-mentioned elements being movable toward the other upon energization of said electromagnetic element, for pressing and arresting sheet material in the path.
8. A device as defined in claim 1, wherein said path-defining means comprises plural supports spaced along the path for engaging said one major surface of sheet material therein.
9. A device as defined in claim 1, wherein said path-defining means comprises a nonmagnetic plate interposed between said second member and said path.
Description:
BACKGROUND OF THE INVENTION
This invention relates to sheet intermittent feed devices, and more particularly it is concerned with a sheet intermittent feed device using an electromagnet and a sheet feed member made of a ferromagnetic material.
Punched cards or other information storing cards in sheet form or web form (hereinafter generally referred to as sheets) are often fed intermittently for reading information stored therein. In one device for intermittently feeding such cards, rollers disposed on the path of movement of the sheets are rotated intermittently by means of an escapement comprising a ratchet wheel, a feed pawl and a check pawl. This device has the disadvantage of being large in size and complex in construction because of the need to use, in addition to the rollers, the ratchet wheel, feed pawl and check pawl. Besides, a suitable means must be used for operating the feed pawl, and this has made it impossible to operate the device at high speed.
SUMMARY OF THE INVENTION
An object of the invention is to provide a novel sheet intermittent feed device, simple in construction, high in operation speed and having a wide range of application, which comprises at least one electromagnet and a ferromagnetic sheet feed member disposed in spaced juxtaposed relationship across a path of movement of a sheet.
According to the invention, there is provided a sheet intermittent feed device comprising at least one electromagnet, a sheet feed member made of a ferromagnetic material, the electromagnet and the sheet feed member being disposed in spaced juxtaposed relationship across a path of movement of a sheet and within the sphere of influence of the magnetic force of the former, means for intermittently exciting the electromagnet to move the sheet feed member intermittently relative to the electromagnet or to move the electromagnet intermittently relative to the sheet feed member in a direction in which the sheet is to be fed along its path of movement, and means for returning the sheet feed member or the electromagnet to its original position from a position to which it has moved intermittently whereby the sheet disposed on its path of movement can be fed intermittently.
The sheet intermittent feed device according to the invention offers many advantages. It is simple in construction and yet permit feeding of a sheet to be effected satisfactorily. It has a wide range of application.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a and 1b are schematic views of the sheet intermittent feed device comprising one embodiment of the invention;
FIG. 2 is a sectional side view of the sheet intermittent feed device comprising a second embodiment of the invention;
FIG. 3 is a perspective view of the device shown in FIG. 2;
FIG. 4 and FIG. 5 are sectional side views of a third embodiment and a fourth embodiment of the invention, showing their application; and
FIG. 6 is a sectional side view of a fifth embodiment of the invention.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
In FIG. 1, there is shown one embodiment of the invention which illustrates the principle of the invention. The device 1 comprises, as shown in FIG. 1a, an electromagnet 2 and a sheet feed member 3 made of a ferromagnetic material (normally wet) disposed in spaced juxtaposed relationship across a path of movement of a sheet 4. The electromagnet 2 and sheet feed member 3 are disposed along the path of movement of the sheet 4 and spaced apart from each other such that the member 3 is disposed within the sphere of influence of the magnetic force of the electromagnet 2.
When the electromagnet 2 is not actuated, the sheet feed member 3 is urged by the biasing force of a spring 5 to move into a position in which it is stationary and in abutting engagement with a stopper 6. While in this position, the member 3 is maintained at its underside in contact with the sheet 4 which rests on rollers supported by shafts 7a and 8a respectively which are rotatably supported by an immovable member (not shown). A guide plate made of a nonmagnetic material and having a smooth upper surface may be used for guiding the sheet 4 and disposed in the path of movement of the sheet 4 near the rollers 7, 8 or in any other position as desired. The sheet feed member 3 is made of iron, nickel or other ferromagnetic material.
When a current is passed to the electromagnet 2 to excite it, the sheet feed member 3 is attracted to the electromagnet 2 against the biasing force of spring 5 and moves, together with the sheet 4, from a position shown in FIG. 1a to a position shown in FIG. 1b in which the member 3 is fully on the electromagnet 2. At this time, the force of attraction exerted by the electromagnet 2 on the sheet feed member 3 is oriented such that the sheet 4 is tightly forced against the rollers 7, 8, so that the sheet is smoothly fed by virtue of the frictional dragging of the underside of the member 3 on the sheet 4. When the member 3 is in its position shown in FIG. 1a, magnetic lines of force flow as indicated by lines T1 and are unstable. However, when it is in its position shown in FIG. 1b, magnetic lines of force are stable as indicated by lines T2.
When the supply of current to the electromagnet 2 is cut off, the sheet feed member 3 is released from the electromagnet 2 and restored to its original position by the biasing force of spring 5. At this time, the member 3 rides on the sheet 4 by its weight only. Thus, if the weight of the member 3 is adjusted beforehand, the member 3 will only slide on the sheet 4 in its return movement and the sheet 4 will never move with the member 3.
If excitation of the electromagnet 2 is carried out intermittently, the aforementioned sheet feed operation will be repeatedly performed and the sheet 4 will be intermittently fed along its path of movement. The distance covered by the sheet in one cycle of feeding operation is substantially equal to a distance α covered by the sheet feed member 3 in its movement from the initial unstable position shown in FIG. 1a to the next stable position shown in FIG. 1b in which it is attracted to the electromagnet 2.
In the aforementioned description, the electromagnet 2 is fixed while the sheet feed member 3 is movable. It is to be understood that the electromagnet 2 may be movable while the member 3 is fixed.
A second embodiment of the invention will be described with reference to FIG. 2 and FIG. 3 in which a path of movement of a sheet 9 is disposed on guide plates 10 and 11 and guide rollers 12, 13 and 14 interposed between the two guide plates 10 and 11.
Disposed beneath the path of sheet 9 is an electromagnet 15 having two poles 15a and 15b interposed between the rollers 12 and 13 and 13 and 14 respectively and disposed adjacent the sheet path. Disposed opposite the electromagnet 15 with respect to the sheet path is a sheet feed member 16 made of a ferromagnetic material and formed therein with slots 16a and 16b. The sheet feed member 16 is covered with a shield plate 17 having opposite ends disposed near the sheet path and is movable under the shield plate.
A torsion spring 19 is mounted on a pin 18 planted on the upper surface of the member 16 in the central portion and connected at opposite ends to pins 20 and 21 planted on the underside of the shield plate 17 and in opposite side marginal portions, so as to urge the member 16 to move rightwardly in FIG. 2. When the electromagnet 15 is not actuated, the sheet feed member 16 is urged by the biasing force of torsion spring 19 to move to the right and has its right end portion abut against a right depending portion of the shield plate 17, and the two slots 16a and 16b are disposed in an initial position in which they are indexed with the two poles 15a and 15b of the electromagnet 15 respectively.
Upon excitation of the electromagnet 15, portions of the sheet feed member 16 disposed rightwardly of the slots 15a, 15b in FIG. 2 are attracted to the poles 15a and 15b respectively and the sheet 9 is frictionally fed leftwardly as the member 16 moves leftwardly in FIG. 2. When the electromagnet 15 is de-actuated, the member 16 is restored to its original position where it stands by for the next sheet feed operation. Thus, the sheet 9 can be intermittently fed leftwardly in FIG. 2 by intermittently exciting the electromagnet 15.
FIG. 4 shows a third embodiment of the invention in which the device according to the invention is mounted to cooperate with a pair of sheet delivery rollers 21 and 22 maintained in pressing engagement with each other. As shown, a sheet guide plate 23 is disposed rightwardly of the rollers 21, 22 and provides a sheet path thereon. Formed in the sheet guide plate 23 are two slots 23a and 23b which are disposed beneath and indexed with one pole 24 a of an electromagnet 24 and a roller 25 and the other pole 24b thereof and another roller 26 respectively.
A sheet feed member 27 made of a ferromagnetic material and formed therein with slots 27a and 27b is disposed opposite the electromagnet 24 with respect to the sheet path and covered with a shield plate 28 disposed above it and formed with a cutout 28a in its left portion in the figure. Received in the cutout 28a for sliding motion is a pin 29 planted on the upper surface of the member 27. A spring 31 is mounted between the pin 29 and another pin 30 planted on the shield plate 28 to urge by its biasing force the sheet feed member 27 to move to a position in which the pin 29 abuts against a right end edge of the cutout 28a, when the electromagnet 24 is not actuated. Thus, when the electromagnet 24 is not actuated, the sheet feed member 24 is in its initial position in which the slots 27a and 27b are indexed with the poles 24a and 24b of the electromagnet 24 respectively. Upon excitation of the electromagnet 24, the member 27 moves leftwardly in FIG. 4 and a sheet 32 also moves in the same direction with the member 27.
Generally, even if the leading end of sheet 32 is disposed near the portions of sheet delivery rollers 21 and 22 which are maintained in engagement with each other, it is not nipped by the two rollers 21, 22 unless a force is exerted on the sheet to urge the same toward the rollers. Therefore, in apparatus wherein a sheet is inserted beforehand as by hand in a position disposed near the sheet delivery rollers, it is required to push and move by some means the sheet toward the rollers before rotation of the latter is initiated. The device according to the invention permits delivery of a sheet to be readily and positively initiated merely by passing a current to the electromagnet intermittently. Thus, feed of the sheet can be initiated automatically and positively.
The device according to the invention can be incorporated in a tape reader as shown in FIG. 5 in which a punched tape 34 is disposed on a guide plate 33 formed in its central portion with a slot 33a. A light source 35 and a light receiving element 36 are disposed above and below the slot 33a respectively to read information stored in the tape 34.
Slots 33b and 33c are formed in a leftward portion of the guide plate 33. One pole 37a of electromagnet 37 and a roller and the other pole 37b thereof and another roller 39 are disposed beneath and indexed with the slots 33b and 33c respectively. Disposed above the slots 33b and 33c is a sheet feed member 40 made of a ferromagnetic material and formed therein with slots 40a and 40b. The member 40 is covered with a shield plate 41.
An electromagnet 42 is mounted on a leftward portion of the shield plate 41. In its initial position, the sheet feed member 40 is disposed beneath the electromagnet 42. The two electromagnets 37 and 42 are alternately excited to move the member 40 rightwardly in reciprocating motion from its position shown in FIG. 5 so as to thereby feed the tape 34 intermittently.
The guide plate 33 is also formed in its rightward portion with a slot 33d in FIG. 5 in which an electromagnet 43 enclosed by a frame 44 is disposed. A brake member 46 made of a ferromagnetic material and enclosed by a frame 45 is disposed opposite the electromagnet 43 with respect to the path of movement of the tape 34. Electromagnet 43 is actuated in synchronism with electromagnets 37 and 42 so as to strictly regulate the distance covered by the tape 34 in its feed movement by the brake member 46 being brought into pressing engagement with the tape 34 as it is attracted to electromagnet 43. This is conductive to a higher degree of precision with which the information stored in the tape is read out.
Other means than the brake member and electromagnet combination may be employed for regulating the distance covered by the tape in its feed movement. The rollers used in all the embodiments shown and described above may be replaced by a guide plate 46 (See FIG. 6) made of aluminum or other non-magnetic material and having a smooth surface.
In FIG. 6, a sheet 47 rests on the guide plate 46, and an electromagnet 48 is disposed beneath the guide plate 46 while a sheet feed member 49 formed therein with slots 49a and 49b is disposed on the sheet 47. The member 49 is covered with a shield frame 50 and has a pin 51 planted on its central portion and extending through a slot 50a formed in the shield frame 50. A spring 53 is mounted between the pin 51 and a pin 52 planted on the shield frame 50 so as to urge the sheet feed member 49 to return to its original position by its biasing force.
If electromagnet 48 is intermittently excited, then the sheet feed member 49 moves rightwardly in FIG. 6 in reciprocating motion, and the sheet 47 is fed intermittently in the same direction.
This invention relates to sheet intermittent feed devices, and more particularly it is concerned with a sheet intermittent feed device using an electromagnet and a sheet feed member made of a ferromagnetic material.
Punched cards or other information storing cards in sheet form or web form (hereinafter generally referred to as sheets) are often fed intermittently for reading information stored therein. In one device for intermittently feeding such cards, rollers disposed on the path of movement of the sheets are rotated intermittently by means of an escapement comprising a ratchet wheel, a feed pawl and a check pawl. This device has the disadvantage of being large in size and complex in construction because of the need to use, in addition to the rollers, the ratchet wheel, feed pawl and check pawl. Besides, a suitable means must be used for operating the feed pawl, and this has made it impossible to operate the device at high speed.
SUMMARY OF THE INVENTION
An object of the invention is to provide a novel sheet intermittent feed device, simple in construction, high in operation speed and having a wide range of application, which comprises at least one electromagnet and a ferromagnetic sheet feed member disposed in spaced juxtaposed relationship across a path of movement of a sheet.
According to the invention, there is provided a sheet intermittent feed device comprising at least one electromagnet, a sheet feed member made of a ferromagnetic material, the electromagnet and the sheet feed member being disposed in spaced juxtaposed relationship across a path of movement of a sheet and within the sphere of influence of the magnetic force of the former, means for intermittently exciting the electromagnet to move the sheet feed member intermittently relative to the electromagnet or to move the electromagnet intermittently relative to the sheet feed member in a direction in which the sheet is to be fed along its path of movement, and means for returning the sheet feed member or the electromagnet to its original position from a position to which it has moved intermittently whereby the sheet disposed on its path of movement can be fed intermittently.
The sheet intermittent feed device according to the invention offers many advantages. It is simple in construction and yet permit feeding of a sheet to be effected satisfactorily. It has a wide range of application.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a and 1b are schematic views of the sheet intermittent feed device comprising one embodiment of the invention;
FIG. 2 is a sectional side view of the sheet intermittent feed device comprising a second embodiment of the invention;
FIG. 3 is a perspective view of the device shown in FIG. 2;
FIG. 4 and FIG. 5 are sectional side views of a third embodiment and a fourth embodiment of the invention, showing their application; and
FIG. 6 is a sectional side view of a fifth embodiment of the invention.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
In FIG. 1, there is shown one embodiment of the invention which illustrates the principle of the invention. The device 1 comprises, as shown in FIG. 1a, an electromagnet 2 and a sheet feed member 3 made of a ferromagnetic material (normally wet) disposed in spaced juxtaposed relationship across a path of movement of a sheet 4. The electromagnet 2 and sheet feed member 3 are disposed along the path of movement of the sheet 4 and spaced apart from each other such that the member 3 is disposed within the sphere of influence of the magnetic force of the electromagnet 2.
When the electromagnet 2 is not actuated, the sheet feed member 3 is urged by the biasing force of a spring 5 to move into a position in which it is stationary and in abutting engagement with a stopper 6. While in this position, the member 3 is maintained at its underside in contact with the sheet 4 which rests on rollers supported by shafts 7a and 8a respectively which are rotatably supported by an immovable member (not shown). A guide plate made of a nonmagnetic material and having a smooth upper surface may be used for guiding the sheet 4 and disposed in the path of movement of the sheet 4 near the rollers 7, 8 or in any other position as desired. The sheet feed member 3 is made of iron, nickel or other ferromagnetic material.
When a current is passed to the electromagnet 2 to excite it, the sheet feed member 3 is attracted to the electromagnet 2 against the biasing force of spring 5 and moves, together with the sheet 4, from a position shown in FIG. 1a to a position shown in FIG. 1b in which the member 3 is fully on the electromagnet 2. At this time, the force of attraction exerted by the electromagnet 2 on the sheet feed member 3 is oriented such that the sheet 4 is tightly forced against the rollers 7, 8, so that the sheet is smoothly fed by virtue of the frictional dragging of the underside of the member 3 on the sheet 4. When the member 3 is in its position shown in FIG. 1a, magnetic lines of force flow as indicated by lines T1 and are unstable. However, when it is in its position shown in FIG. 1b, magnetic lines of force are stable as indicated by lines T2.
When the supply of current to the electromagnet 2 is cut off, the sheet feed member 3 is released from the electromagnet 2 and restored to its original position by the biasing force of spring 5. At this time, the member 3 rides on the sheet 4 by its weight only. Thus, if the weight of the member 3 is adjusted beforehand, the member 3 will only slide on the sheet 4 in its return movement and the sheet 4 will never move with the member 3.
If excitation of the electromagnet 2 is carried out intermittently, the aforementioned sheet feed operation will be repeatedly performed and the sheet 4 will be intermittently fed along its path of movement. The distance covered by the sheet in one cycle of feeding operation is substantially equal to a distance α covered by the sheet feed member 3 in its movement from the initial unstable position shown in FIG. 1a to the next stable position shown in FIG. 1b in which it is attracted to the electromagnet 2.
In the aforementioned description, the electromagnet 2 is fixed while the sheet feed member 3 is movable. It is to be understood that the electromagnet 2 may be movable while the member 3 is fixed.
A second embodiment of the invention will be described with reference to FIG. 2 and FIG. 3 in which a path of movement of a sheet 9 is disposed on guide plates 10 and 11 and guide rollers 12, 13 and 14 interposed between the two guide plates 10 and 11.
Disposed beneath the path of sheet 9 is an electromagnet 15 having two poles 15a and 15b interposed between the rollers 12 and 13 and 13 and 14 respectively and disposed adjacent the sheet path. Disposed opposite the electromagnet 15 with respect to the sheet path is a sheet feed member 16 made of a ferromagnetic material and formed therein with slots 16a and 16b. The sheet feed member 16 is covered with a shield plate 17 having opposite ends disposed near the sheet path and is movable under the shield plate.
A torsion spring 19 is mounted on a pin 18 planted on the upper surface of the member 16 in the central portion and connected at opposite ends to pins 20 and 21 planted on the underside of the shield plate 17 and in opposite side marginal portions, so as to urge the member 16 to move rightwardly in FIG. 2. When the electromagnet 15 is not actuated, the sheet feed member 16 is urged by the biasing force of torsion spring 19 to move to the right and has its right end portion abut against a right depending portion of the shield plate 17, and the two slots 16a and 16b are disposed in an initial position in which they are indexed with the two poles 15a and 15b of the electromagnet 15 respectively.
Upon excitation of the electromagnet 15, portions of the sheet feed member 16 disposed rightwardly of the slots 15a, 15b in FIG. 2 are attracted to the poles 15a and 15b respectively and the sheet 9 is frictionally fed leftwardly as the member 16 moves leftwardly in FIG. 2. When the electromagnet 15 is de-actuated, the member 16 is restored to its original position where it stands by for the next sheet feed operation. Thus, the sheet 9 can be intermittently fed leftwardly in FIG. 2 by intermittently exciting the electromagnet 15.
FIG. 4 shows a third embodiment of the invention in which the device according to the invention is mounted to cooperate with a pair of sheet delivery rollers 21 and 22 maintained in pressing engagement with each other. As shown, a sheet guide plate 23 is disposed rightwardly of the rollers 21, 22 and provides a sheet path thereon. Formed in the sheet guide plate 23 are two slots 23a and 23b which are disposed beneath and indexed with one pole 24 a of an electromagnet 24 and a roller 25 and the other pole 24b thereof and another roller 26 respectively.
A sheet feed member 27 made of a ferromagnetic material and formed therein with slots 27a and 27b is disposed opposite the electromagnet 24 with respect to the sheet path and covered with a shield plate 28 disposed above it and formed with a cutout 28a in its left portion in the figure. Received in the cutout 28a for sliding motion is a pin 29 planted on the upper surface of the member 27. A spring 31 is mounted between the pin 29 and another pin 30 planted on the shield plate 28 to urge by its biasing force the sheet feed member 27 to move to a position in which the pin 29 abuts against a right end edge of the cutout 28a, when the electromagnet 24 is not actuated. Thus, when the electromagnet 24 is not actuated, the sheet feed member 24 is in its initial position in which the slots 27a and 27b are indexed with the poles 24a and 24b of the electromagnet 24 respectively. Upon excitation of the electromagnet 24, the member 27 moves leftwardly in FIG. 4 and a sheet 32 also moves in the same direction with the member 27.
Generally, even if the leading end of sheet 32 is disposed near the portions of sheet delivery rollers 21 and 22 which are maintained in engagement with each other, it is not nipped by the two rollers 21, 22 unless a force is exerted on the sheet to urge the same toward the rollers. Therefore, in apparatus wherein a sheet is inserted beforehand as by hand in a position disposed near the sheet delivery rollers, it is required to push and move by some means the sheet toward the rollers before rotation of the latter is initiated. The device according to the invention permits delivery of a sheet to be readily and positively initiated merely by passing a current to the electromagnet intermittently. Thus, feed of the sheet can be initiated automatically and positively.
The device according to the invention can be incorporated in a tape reader as shown in FIG. 5 in which a punched tape 34 is disposed on a guide plate 33 formed in its central portion with a slot 33a. A light source 35 and a light receiving element 36 are disposed above and below the slot 33a respectively to read information stored in the tape 34.
Slots 33b and 33c are formed in a leftward portion of the guide plate 33. One pole 37a of electromagnet 37 and a roller and the other pole 37b thereof and another roller 39 are disposed beneath and indexed with the slots 33b and 33c respectively. Disposed above the slots 33b and 33c is a sheet feed member 40 made of a ferromagnetic material and formed therein with slots 40a and 40b. The member 40 is covered with a shield plate 41.
An electromagnet 42 is mounted on a leftward portion of the shield plate 41. In its initial position, the sheet feed member 40 is disposed beneath the electromagnet 42. The two electromagnets 37 and 42 are alternately excited to move the member 40 rightwardly in reciprocating motion from its position shown in FIG. 5 so as to thereby feed the tape 34 intermittently.
The guide plate 33 is also formed in its rightward portion with a slot 33d in FIG. 5 in which an electromagnet 43 enclosed by a frame 44 is disposed. A brake member 46 made of a ferromagnetic material and enclosed by a frame 45 is disposed opposite the electromagnet 43 with respect to the path of movement of the tape 34. Electromagnet 43 is actuated in synchronism with electromagnets 37 and 42 so as to strictly regulate the distance covered by the tape 34 in its feed movement by the brake member 46 being brought into pressing engagement with the tape 34 as it is attracted to electromagnet 43. This is conductive to a higher degree of precision with which the information stored in the tape is read out.
Other means than the brake member and electromagnet combination may be employed for regulating the distance covered by the tape in its feed movement. The rollers used in all the embodiments shown and described above may be replaced by a guide plate 46 (See FIG. 6) made of aluminum or other non-magnetic material and having a smooth surface.
In FIG. 6, a sheet 47 rests on the guide plate 46, and an electromagnet 48 is disposed beneath the guide plate 46 while a sheet feed member 49 formed therein with slots 49a and 49b is disposed on the sheet 47. The member 49 is covered with a shield frame 50 and has a pin 51 planted on its central portion and extending through a slot 50a formed in the shield frame 50. A spring 53 is mounted between the pin 51 and a pin 52 planted on the shield frame 50 so as to urge the sheet feed member 49 to return to its original position by its biasing force.
If electromagnet 48 is intermittently excited, then the sheet feed member 49 moves rightwardly in FIG. 6 in reciprocating motion, and the sheet 47 is fed intermittently in the same direction.