US3541277A

US3541277A - Web actuated switch

Info

Publication number: US3541277A
Application number: US732702A
Authority: US
Inventors: Daniel L Miller; Terry B Prince
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1968-05-28
Filing date: 1968-05-28
Publication date: 1970-11-17
Anticipated expiration: 1987-11-17
Also published as: BE733621A; FR2009501A1; DE1926850B2; GB1242771A; DE1926850A1; JPS5035663B1

Description

Nov. 17, 1970 D. L. MILLER ETAL 3,541,277

WEB ACTUATED SWITCH 2 Sheets-Sheet 1 Filed May 28, 1968 I u t: r

0. L. MILLER gf T. B. PRINCE A T TORNE V Nov. 17, 1970 MILLER ETAL 3,541,217

WEB ACTUATED SWITCH Filed May 28, 1968 2 Sheets-Sheet 2 !/I////I////////l United States Patent 3,541,277 WEB ACTUATED SWITCH Daniel L. Miller and Terry B. Prince, Indianapolis, Ind., assignors to Bell Telephone Laboratories, Incorporated, Murray Hill, N.J., a corporation of New York Filed May 28, 1968, Ser. No. 732,702 Int. Cl. H01h 25/14, 43/08 US. Cl. 200-61.13 3 Claims ABSTRACT OF THE DISCLOSURE FIELD OF THE INVENTION This invention relates to the field of electrical circuit control and within that field to switches operated responsive to the persence of coding of a web moving relative to the switches.

DESCRIPTION OF THE PRIOR ART A nonconductive web having a plurality of rows of spaced index positions has information commonly stored thereon by perforating particular index positions within each row, the information stored being directly related to the particular index position or positions within a row that are perforated. The information is then retrieved from the web by passing it through a reading device that scans the web, detects the presence of the perforations, and translates the stored information into electrical signals.

One common reading device employs a group of elec trical contacts, the perforated web passing between the contacts and conductors underlying the contacts. The individual contacts are aligned with the index positions on the web, and when a perforation moves beneath a contact, the contact extends through the perforation and engages the conductor on the other side of the web to close a circuit.

The disadvantage of such a sensing arrangement is that if the web carries any contaminants, such as lint or dirt, the contaminants tend to collect on the contacts and may result in failure of a contact to make an electrical connection with the conductor therebeneath when a perforation appears.

In addition, since the contacts are current carrying members, should a conductive body be inserted into the reading device instead of the nonconductive web, damage to the device may result.

An alternative approach for detecting the perforations which does not suffer from these deficiencies employs a group of nonconductive sensing members that serve as switch actuators rather than switch elements. Each sensing member is associated with an individual contact of a switch and rides on the web in juxtaposition with an individual index position. When a perforation appears, the sensing member moves therein and this movement causes the associated contact to engage a second contact to close the switch.

However since the amount of motion involved in moving into a perforation in a web is small, the spacing of the contacts in this arrangement is critical and little wiping action is provided to clean the contact faces.

Furthermore, where the lever principle is used to increase the effective actuating motion provided by the movement of the sensing members into the perforations, there is still the problem of providing the necessary dwell time, that is, the time during which the contacts remain actuated, without limiting the motion of the web to a slower than desirable rate.

SUMMARY OF THE INVENTION The web actuated switch of the present invention obviates all of the aforementioned problems. It comprises a pivotally mounted nonconductive sensing member having a feeler portion and an actuating portion, the sensing member being biased to move the feeler portion toward the web. The feeler portion includes a slot that extends parallel to the path of movement of the web and a wheel for making rolling engagement with the web is mounted in and is movable along the length of the slot.

As the leading edge of a perforation moves past the Wheel, the interacting forces cause the wheel to move toward the trailing end of its slot. The wheel thereupon moves into the perforation, permitting the sensing member to pivot, and the wheel remains in the perforation until forced out by the trailing edge, the trailing edge first moving the wheel to the leading end of its slot. As a result, the length of time during which the sensing member remains in a perforation is increased and the rate of movement of the web need not be impeded by the dwell time requirements of the contacts. 7

The actuating portion of each sensing member includes a permanent magnet, and a magnetically actuated switch is positioned adjacent to each magnet. The movement of the feeler portion of a sensing member into and out of a perforation displaces the actuating portion of the sensing member and results in the actuation of the associated switch. 1

By employing a magnetically actuated switch, the switch itself may be encapsulated in a controlled atmosphere whereby the contacts are protected from contamination. In addition, the switch may be advantageously selected so that it closes during the movement of the sensing portion into a perforation and opens when the sensing member is most of the way out of the perforation. Consequently, the switch remains closed for a longer period of time than the feeler portion is actually resting in a perforation.

DESCRIPTION OF T HE DRAWING FIG. 1 is an exploded perspective view of a reading device employing the Web actuated switch of this invention;

FIG. 2 is a sectional view of the switch showing the relative position of the elements of the switch when a'sensing member is in a card insertion position;

FIG. 3 is the same as FIG. 2 showing the relative position of the elements of the switch when a sensing member is in a reading position and is in engagement with the surface of the Web;

FIG. 4 is an enlarged portion of FIG. 3 showing the interaction between a sensing member and the leading edge of a perforation in the web; and

3 FIG. 5 is the same as FIG. 2 showing the relative position of the elements of the switch 'when a sensing mem ber is in a reading position and is in engagement with a perforation in the web.

ILLUSTRATIVE EMBODIMENT OF THE INVENTION General description Referring to FIG. 1, a reading device incorporating the web actuated switch of this invention comprises a drive assembly 10, a scanning assembly 12, and a control assembly 14. The scanning assembly 12 accommodates an encoded web or card 15 that includes a plurality of parallel rows of spaced data index positions 16, and information is coded on the card by perforating one or more of these index positions in each row. The card 15 also includes an individual control index position 17 located between adjacent rows of data index positions 16, a perforation in a control index position serving to stop the movement of the card during scanning. Finally, the card 15 includes a column of sprocket holes 18, and when the card as inserted into the scanning assembly 12, the sprocket holes interact with the drive assembly to store energy therein. Then upon operation of the control assembly 14, the drive assembly 10 moves the card out of the scanning assembly 12 during which time scanning of the encoding on the card takes place.

Drive assembly The drive assembly 10 includes a pair of side plates 20 and 22 joined by a rear plate 24. An auxiliary plate 25 is spaceably mounted to the side plate 20, and a shaft 26- is journaled in the side plate 22 and the auxiliary plate 25. The shaft 26 has a pair of spaced drums 2-8 and 30 and a sprocket wheel 32 fixedly mounted thereon, the

- sprocket wheel being adapted to engage the sprocket holes 18 in the card 15 and the drums having rubber rings 34 thereon for pressing against the back surface of the card. In addition, the shaft 26 has a motor spring 35 disposed thereabout, the motor spring extending Within the drum 30. One end of the motor spring 35 is hooked into a cavity on the inside of the drum 30 while the other end of the spring is secured to a spring retainer 36 rotatably mounted on the shaft 26 adjacent to the drum 28 and held immobile by a hook on the rear plate 24.

The interaction between the sprocket holes 18 on the card 15 and the sprocket wheel 32 as the card is inserted into the scanning assembly 12 results in the sprocket wheel and thereby the shaft 26 and drums 28 and 30 being rotated in a clockwise direction. Since one end of the motor spring 35 is held immobile while the other end rotates with the drum 30, the rotation of the sprocket wheel 32 winds up the motor spring to store energy therein, the motor spring tending to rotate the sprocket wheel in a counter-clockwise direction.

A pawl 3-8 pivotally mounted between the side plate 20 and the auxiliary plate 2'5 cooperates with a ratchet wheel 40 fixedly mounted on the shaft 26 to serve as a latch for the sprocket wheel 32. The pawl 3-8 has a rear arm (not shown) that extends into juxtaposition with the ratchet wheel 40 and a forward arm that extends beyond the front edge of the side plate 20. A spring member 42 biases the pawl 38 in a clockwise direction and thereby biases the rear arm into engagement with the teeth on the ratchet Wheel 40. I i

The teeth on the ratchet wheel 40- are shaped so that with the rear arm of the pawl 38 in engagement therewith, the ratchet wheel is able to rotate in a clockwise direction but is unable to rotate in a counterclockwise direction. Hence the engagement of the rear arm with the ratchet wheel 40 permits insertion of the card 15 into the scanning assembly 12 but prevents its removal. To move the card 15 out of the scanning assembly 12, the rear arm is, in a manner hereinafter described, disengaged from the ratchet wheel 40 and the motor spring 35 is thereby permitted to rotate the sprocket wheel 32 in a counterclockwise direction.

A gear 44 fixedly mounted on the shaft 26 alongside of the ratchet wheel 40 serves to couple the shaft and thereby the sprocket wheel 32 to a governor 45 to control the rate at which the card is moved out of the scanning assembly 12. In addition, a detent 46- rotatably mounted on the shaft 26 adjacent to the sprocket wheel 32 interacts with a tab (not shown) fastened to the side plate 22 and a boss protruding from the side of the sprocket wheel to terminate the counterclockwise rotation of the sprocket wheel after the card 15 is moved out of engagement with the sprocket wheel.

Scanning assembly The scanning assembly 12 includes a frame 50 consisting of an entryway '52 for receiving the card 15, a front wall 54 and a pair of side walls 55 and 56-. The

side walls

55 and 56 have bosses 57 thereon that are respectively accommodated by notches '58 in the side plates 20 and 22 of the drive assembly 10 to properly locate the scanning assembly 12 with respect to the drive assembly, and with the scanning assembly 12 so located, a guide 60 is captured between the rear plate 24 and the front wall 54. The guide 60 has opposing pairs of tabs 62 that are accommodated by slots in the rear plate 24 and the front Wall 54, and the guide has a pair of springs 65 that bear against and act to bias the guide away from the side wall 55. Consequently, the guide 60 is laterally displaceable within. the slots.

When a card 15 is inserted into the entryway 52, the rings 34 on the drums 28 and 30- direct the card along the front wall 54 and the guides 60- directs the card along the side wall 56 whereby the sprocket holes 18 in the card engage the sprocket wheel 32. Then when the card is moved out of the entryway 52 by the drive assembly 10', the guide 60 serves to prevent the card from cocking so that the card moves perpendicular to a row of apertures 66 in the front wall 54, only one of which is shown. The number and spacing of the apertures 66 is the same as the number and spacing of the data index positions 16 in each row on the card 15, and as the card moves along the front Wall 54, the index positions register with the apertures. In addition, an aperture 6-8 in the front wall 54 is arranged to register with the control index position 17.

Associated with each aperture 66 is a sensing member 70 comprising an elongated stem 72 having an actuating portion 74 at one end thereof, a feeler portion 75 at the other end thereof, and a hub portion 76 in between. The actuating portion 74 projects forwardly from the stem 72 and has a permanent bar magnet 7-8 mounted therein. The feeler portion 75 projects rearwardly from. the stem 72, and the free end of the feeler portion has a flat face and is bifurcated, both bifurcations having a wheel slot that extends parallel to the face. A wheel 80 is situated between the bifurcations and has a shaft that is rotatably mounted in and movable along the length of the wheel slots. The wheel 80 is of a size so that a segment of its surface protrudes beyond the face of the feeler portion.

The hub portion 76 of each sensing member 70 is pivotally mounted on a shaft 82 supported between two posts 83 on the front wall 54, the stems 72 being positioned in notches in a ledge 84 to locate each sensing member in a particular position along the length of the shaft. When so mounted, the feeler portion 75 of each sensing member 70 is positioned within an individual aperture 66 in the front wall, and the actuating portion 74 of each sensing member is located in juxtaposition with a shelf 85 at the lower end of the frame '50. The shelf 85 has an indi vidual channel underlying each actuating portion 74, and

. a glass sealed reed switch 86 is mounted in each channel.

Finally, an individual spring member 88 associated with each sensing member 70 biases it in a counterclockwise direction, the spring thereby acting to move the feeler portion 75 through the associated aperture 66. However, as hereinafter explained, the counterclockwise rotation of each sensing member 70 is limited by either the engagement of its feeler portion 75 with a card 15 or by the engagement of its stem 72. with a deflecting vane 90 rotatably mounted in posts 91 extending from the frame 50. To the left of the sensing member 70 is a detecting member 92 the lower end of which is pivotally mounted in gimbals 93 on the front wall 54. The upper end of the detecting member 92 has a tapered nose portion 94 that extends rearwardly through the aperture 68 in the front wall 54 and a stop portion 95 that extends forwardly and interacts with the control assembly 14.

Control assembly The control assembly 14 includes a front plate 96 that is fastened to laterally extending tabs 97 on the side plates 20 and 22 of the drive assembly 10. Space nail head posts 98 extends from the forward surface of the front plate 96 and are accommodated by spaced key hole slots 99 in a start bar 100. The nail head posts 98 and key hole slots 99 cooperate to slidably support the start bar 100 on the front plate 96 and to direct the movement of the bar along a vertical path parallel to the surface of the front plate, the bar being biased to an upward position by a spring 102.

The start bar 100 has a frame 104 that accommodates a forwardly extending finger 105 on the deflecting vane 90 of the scanning assembly 12. The start bar 100 also has a forwardly extending stud 106 that is accommodated by an opening in a latch member .108. The latch member 108 is pivotally mounted on the front plate 96 and a leaf spring 110 biases the latch member toward the start bar 100 and thereby maintains the latch member positioned over the stud 106. In addition, the latch member 108 is of a length to engage the forward arm of the pawl 38 of the drive assembly and thereby extends in juxtaposition with a reject bar 112.

The reject bar 112 is slidably mounted on the front plate 96 for vertical movement along the face thereof in the same manner as the start bar 100 is biased to an upward position by the spring 102. The reject bar 1112 includes a cam 114 on which the latch member 108 normally rests and an opening 115 that is in registration with an opening in the front plate 96 and through which the stop portion 95 of the detecting member protrudes.

Description of operation Prior to the initiation of the operation of the reading device, the start bar 100 is in an upward position and the interaction between the frame 104 thereof and the finger 105 of the deflecting vane 90 locates the deflecting vane in the position shown in FIG. 2. It is seen that the free end of the deflecting vane 90 is in engagement with the stems 72 of the sensing member 70 and has rotated the sensing members in a clockwise direction so that the feeler portions 75 are withdrawn from the card channel between the rear plate 24 and the front wall 54. Thus when the card is inserted into the channel there is no engagement between the card and the feeler portions 75. The ease with which the card 15 is inserted into the channel is thereby increased and the wear on the card and feeler portions '75 is thereby reduced. The card 15 when inserted does however engage the sprocket wheel 3-2 and wind up the motor spring 35 in the previously described manner.

Following the insertion of the card 15 the operation of the reading device is initiated by moving the start bar 100 to a downward position and then releasing it. The downward movement of the start bar 100 pivots the latch member 108 downward, and the latch member under the bias of the spring 110 moves beneath the forward arm of the pawl 38, the cam 114 of the reject bar 112, and the stop portion 95 of the detecting member 92. Then when the start bar 100 is released, it is moved upward by the spring 102 until it is arrested by its engagement with the under side of the stop portion 95.

In this position of the latch member 108, it extends 'just beneath the cam i114 and its free end deflects the forward end of the pawl 38 upward whereby the rear arm is disengaged from the ratchet wheel 40. The motor spring 35 is then free to rotate the sprocket wheel 32 and thereby move the card 15 upward out of the card channel. Furthermore, in this position of the latch member 108, it biases the nose portion 94 of the detecting member 92 against the card 15, the upward force exerted by the latch member providing a rearward force component because of the location of the pivot point of the detecting member.

Finally, in this position of the start bar the frame 104 is essentially disengaged from the finger on the deflecting vane 90, and the springs 88 associated with the sensing members are therefore permitted to move the wheels 80 of the feeler portions 75 into engagement with the surface of the card 15 as shown in FIG. 3. Although this moves the permanent magnet 78 of the actuating portions 74 into closer proximity with the associated reed switches 86, the magnets are not in the position necessary to close the switches.

The point of contact of each wheel 80* with the surface of the card 15, hereinafter referred to as the normal point of contact, is at the intersection of the circumference of the wheel with a radius of the wheel drawn perpendicular to the plane of the card. Since the feeler portion 75 extends essentially perpendicular to the card 15, the normal point of contact provides a force that presses the shaft of the wheel 80 perpendicular to the back side of the wheel slots. Thus when the card 15 is moved upward by the sprocket wheel 32, the wheeel 80 rides to the top of the wheel slots.

However, when a perforation moves into juxtaposition with a wheel 80, a change occurs in the direction of the force acting on the wheel. Referring to FIG. 4, as the leading edge of the perforation moves past the wheel 80, the point of contact moves upward from the normal point of contact. Since the force acting on the wheel is perpendicular to a tangent taken at the point of contact, the force changes from one perpendicular to the wheel slots to one extending at an acute angle to the wheel slots. This latter force, indicated in FIG. 4, as F,,, includes a component F that extends perpendicular to the wheel slots and a component =F that extends downward parallel to the wheel slots, and shortly after the leading edge of the perforation moves past the normal point of contact, the force F becomes sufficient to cause the wheel 80 to shift to the lower end of the wheel slots.

With this change in position, the wheel '80 is able to move into the perforation. The spring 88 biases the face of the feeler portion 75 against the surface of the card and as the sensing member 70 pivots from the position shown in FIG. 3 to the position shown in FIG. 5 the permanent magnet 78 of the actuating portion 74 closes the reed switch 86.

The wheel 80 remains at the lower end of the wheel slots until the trailing edge of the perforation engages the wheel and moves it to the upper end of the slots. Thereafter the trailing edge of the perforation forces the wheel 80 out of the perforation and back onto the surface of the card 15, pivoting the sensing member from the position shown in FIG. 5 to the position shown in FIG. 3. Since the magnetic force necessary to maintain the reed switch 86 closed is significantly less than the magnetic force necessary to close it, the switch remains closed until just Fefore the wheel 80 is again in contact with the card surace.

From the foregoing it is seen that by providing a pivotal sensing member with web engaging means that is rotatable and movable along a path parallel to the direction of movement of the web and by using the pivotal motion of the sensing member to actuate a magnetic switch, an improved web actuated switch is achieved. Compared to the switches of the prior art, the sensing member of this invention reacts more rapidly to the presence of the coding, it remains in contact with the coding for a longer period of time, and the switch itself remains actuated for a still longer period of time.

Referring again to FIG. 1, if there is a perforation in a control index position 17, the nose portion 94 of the detecting member 92, under the bias of the latchmember moves therein. This results in the stop portion 95 of the detecting member 92 moving out of the path of the latch member .108, whereupon the spring 102 is permitted to move the start bar 100 upward, the start bar in turn pivoting the latch member upward. The cam 114 on the reject bar 112 deflects the latch member 108 forward, and the free end of the latch member moves past the forward arm of the pawl 38. The spring member 42 rotates the pawl 38 in a clockwise direction to move the rear arm thereof into engagement withthe ratchet wheel 40, and the rotation of the shaft 26 and thereby the sprocket wheel 32 is arrested and the movement of the card stopped. The card 15 when stopped is located with the space between two rows of data index positions 16 in juxtaposition with the wheels 80 of the sensing members 70.

The movement of the card 15 is thereafter reinitiated by again depressing and releasing the start bar 100 to again disengage the pawl 38 from the ratchet wheel 40. Then when the end of the card 15 moves past the detecting member 92 it reacts in the same way as above to release the start bar 100 and the pawl 38.

If at any time during the scanning of the card 15 it becomes desirable to terminate the scanning and release the card, the reject bar 112 is depressed. The cam 114 thereon deflects the latch member 108 forward beyond the end of the stop portion 95 of the detecting member 92 and permits the start bar 100 and the latch bar to move upward under the bias of the spring 102. At the same time a shoulder 116 on the reject bar 112 engages a bell crank 118 mounted on the side plate of the drive assembly 10 and rotates the bell crank to deflect the forward arm of the pawl 38 upward. The rear arm of the pawl 38 is thereby moved out of engagement with the ratchet wheel 40, and the motor spring 35 is permitted to move the card 15 out of the card channel.

Although a specific embodiment of the invention has been shown and described, it will be understood that it is but illustrative and that various modifications may be made therein without departing from the scope and spirit of this invention as defined in the appended claims.

What is claimed is:

1. A switch actuable responsive to perforations in a web moving relative to the switch, the switch comprising:

a pivotally mounted sensing member for detecting the presence of the perforations in the web, the sensing member having a feeler portion and anactuating portion, the sensing member being biased to move the feeler portion toward the web, and the feeler portion having a slot the length of which extends parallel to the path of movement of the web;

means making rolling engagement with the surface of the web, the rolling means mounted within the slot in the feeler portion and movable along the length of the slot, the feeler portion'and thereby the actuating portion being deflected responsive to the engagement of the rolling means with a perforation in the web; and

switch means mounted adjacent to the actuating portion, the switch means being actuate d'responsive to the deflection of the actuating portion.

2. A web actuated switch as in claim 1 further including means controlling the movement of the web and means coupled to the web controlling means for deflecting the sensing member, the web controlling means being moved from a first to a second position to initiate the movement of the web and returning from the second to the first position upon termination of the movement of the Web, the web controlling means when moved to the first position causing the deflecting means to pivot the sensing member so as to move the feeder portion away from the web and the web controlling means when moving to the second position moving the deflecting means out of engagement with the sensing member whereby the feeder portion moves into engagement with the web.

.3. The web actuated switch as in claim 1 wherein the feeler portion is bifurcated, both bifurcations having a slot the length of which extends parallel to the path of movement of the web, and the rolling means comprises a wheel situated between the bifurcations and having a shaft that is rotatably mounted in and movable along the length of the slots.

References Cited UNITED STATES PATENTS 2,656,497 10/ 1953 Schweighofer et al. 200- 16 X 3,201,537 8/ 1965 Klatte et al ZOO-61.4 1 3,402,269 9/1968 Gregory ZOO-61.13

HERMAN o. JONES, Primary Examiner U.S. Cl. X.R.