US3449533A - Electrical switches and devices employing electrical switches - Google Patents

Description

June 10, 1969 T. Q TAYLQR;

ELECTRICAL SWITCHES AND DEVICES EMPLOYING ELECTRICAL SWITCHES Sheet Filed Feb. 15. 1967 O0 0 O O0 0 O o O O O D o o AH O O k\ 00 o o o o June 10, 1969 'r. c. TAYLOR 3 ELECTRICAL SWITCHES AND DEVICES EMPLOYING ELECTRICAL SWITCHES She et Z 01" 2 Filed Feb. 15. 1967 zg 22 1 2/a United States Patent 3,449,533 ELECTRICAL SWITCHES AND DEVICES EMPLOY- ING ELECTRICAL SWITCHES Thomas Charles Taylor, Farlington, England, assignor to Sealectro Limited, Farlington, England, a British company Filed Feb. 15, 1967, Ser. No. 616,252 Claims priority, application Great Britain, Feb. 16, 1966,

6,862/66 Int. (:1. H01h 43/08, 3/00, 9/00 US. Cl. 20046 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to electrical switches and to devices employing electrical switches, for example, devices for sensing the holes in punched cards or webs (herein called cards).

According to the invention an electrical switch comprises a flexible blade which is anchored at one end, the blade having or providing a movable contact member intermediate in the length of the blade, a stop which engages one side of the blade and which is located between the said movable contact member and the other end of the blade, and a fixed contact member located opposite the said movable contact member for engagement thereby, the stop member being so arranged that transverse movement of the said other end of the blade flexes the blade about the stop as a fulcrum and moves the movable contact member into and out of engagement with the fixed contact member.

In one form of the invention the blade is resiliently biassed to hold the movable contact member in engagement with the fixed contact member and the stop is located on the same side of the blade as the fixed contact member whereby movement of the said other end of the blade to flex the blade about the stop causes the movable contact member to move away from the fixed contact member and hence to open the contact members of the switch.

In another form of the invention the blade is resiliently biassed to hold the movable contact member separated from the fixed contact member and the stop is located on the opposite side of the blade from the fixed contact member whereby movement of the said other end of the blade to flex the blade about the stop causes the movable contact member to move into engagement with the fixed contact member and hence to close the contact members of the switch.

The invention also includes a device for sensing the holes in punched cards comprising a support for a card to be sensed, a switch as claimed in any one of claims 1 to 3 for each station to be sensed, the blades of the switches being generally substantially perpendicular to a card on the card support with the said other ends of the blades positioned to contact the card and sense the holes, and means for moving the said other ends to flex the blades about the stops whereby said other ends have components of movement parallel to the card and also towards and away from the card and return movements of blades which do not sense holes will be restricted by engagement with the card.

Preferably the card support is vertical and the blades are substantially horizontal.

It is also preferred that the blades are arranged in parallel rows, the means for flexing the said other ends of the blades in one or more rows being coupled for operation in unison. In this case, the card support is preferably arranged to move in unison with the means for flexing the said other ends of the blades.

By way of example a specific construction of electrical switch and of a card sensing device incorporating the switch in accordance with the invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a view of the switch, movable and fixed contact members of the switch being held in a moulding of insulating material;

FIGURE 2 is a perspective view of the card sensing device;

FIGURE 3 is a section through the device shown in FIGURE 2, which section shows two sensing pins only, one of which is in engagement with an associated fixed contact and the other of which is out of engagement, each pin and its associated fixed contact providing the movable and fixed contact members of the switch shown in FIG- URE 1;

FIGURE 4 is an enlarged view of the movable ends of two of the sensing pins of the device shown in FIGURES 2 and 3, one of which pins has sensed a hole in a card; and

FIGURE 5 is a view of a modified construction of switch.

The subject of this example (especially FIGURES 1 to 4) comprises an electrical switch having movable and fixed contact members and a card sensing device employing a plurality of the switches, the movable contact members of the switches being used as the sensing pins of the sensing device. The following description will thus describe the switch as part of the sensing device but it is to be appreciated that the invention includes the construction of the switch per se. For example, the switch may be used as part of a jack plug in a plug board.

With reference to FIGURES l to 4, a card 9 to be sensed has 960 separate positions in which a hole may be punched. The card sensing device is thus provided with 960 sensing pins 10 arranged in 12 parallel rows 11 arranged one on top of each other. The device is also provided with a slot 13 with a card support 14 on the remote side of the slot from the pins 10. The card support is made up from a moulding made of, e.g. material marketed under the trademark Bakelite, the moulding having recesses 15 aligned with each row of pins.

Each pin 10 is formed from a length of beryllium copper strip or, as in this example, of wire which has first been flattened at 16 into strip form to form a blade portion having increased flexibility. The flattened section 16 of each pin is inserted into a recess in a moulding 17, made of insulating material, the ends 18, 19 of the pin projecting from the ends of the moulding. The pin is also held at a point 20 adjacent its end 18 and one surface of the pin adjacent its other end 19 engages at a point 22 a surface or stop member 21 forming part of the moulding. The design of the moulding is such that the end 19 of the pin may be flexed or moved in a direction tending to pivot the end of the pin about the point 22, i.e. in the direction of arrow A, the point 22 thereby acting as a fulcrum. Such movement of the end 19 of the pin will cause a deflection of the centre or flattened section 16 in the opposite direction. With regard to FIGURE 1, the movable end 19 of the pin is shown in its relaxed position, which '3 position is defined by an abutment 23 forming part of the moulding 17.

Each moulding 17 also houses a contact 24 which is formed from similar wire to that of the above-described pin 10. One end 25- of the contact projects from the moulding adjacent the end 18 of the pin and the contact is held in the moulding at a point 27 in a similar manner to that in which the pin is fixed at point 20. The other end 28 of the contact is, in this example, flattened and the design of the moulding is such that the contact engages, at point 29, the centre section 16 of the pin, when the pin is in its relaxed position. The end 28 of the contact is also split in two by a lengthwise slit adjacent point 29 to provide two contact surfaces between the contact and the pin. The ends 18, 25 of the pin and contact respectively act as contacts-for an electrical circuit. Also, in the case.of the present example, the end 19 of the pin is capable of sensing a hole in the card to be sensed.

For each row of pins, a suitably insulated tie-bar 30 (see FIGURES 3 and 4) is provided and a mechanism is provided for moving the tie-bars simultaneously first in the direction constituted by FIGURE A (see FIGURE 1) and then in the opposite direction. The tie-bars 30 are thereby capable of flexing the pins by moving the movable ends 19 of the pins in the direction of arrow A (see FIGURE 1) and then allowing the ends and hence the pins to return at least a part way towards their relaxed positions when the bars are moved in the opposite direction. As shown in FIGURE 4, each pin that senses a hole 31 in the card 9 will return to its relaxed position and each pin that does not sense a hole is retained partly flexed by the card itself. Also, as described above, it is only when the pin moves to its fully relaxed position that the pin will engage its associated contact and hence complete the electrical circuit, of which the pin and the contact form a part.

The current in each electric circuit will normally be about 1 amp. and a locking mechanism is thus provided to prevent the electric circuits being completed when a card is not being sensed, since with no card 9 in the slot 13 each pin is in its relaxed position and hence engages its associated contact. This locking mechanism comprises a movable arm or switch at the base of the slot 13 which is tripped by the forward end of the card when it is in its position for the holes therein to be sensed.

The mechanism provided for moving the tie-bars 30 to move the movable ends 19 of the pins comprises a cranked lever 32, pivotally mounted to the casing of the device such that the arm 33 of the lever can be moved by the operator to eifect movement of the other arm 34 and hence upward movement (as viewed in FIGURE 3) of both the card support 14 and each of the tie-bars 30. Such movement of the tie-bars will move the movable ends of the pins, the pins thereby allowing a card to be inserted into the slot 13. The return movement of the arm 33 of the lever 32 is effected, or at least assisted, by a spring 35 and the return movement of the card support and the tiebars is effected by a spring 36. Safety means to prevent the insertion of a card without operation of the arm 33 of the lever 32 is either provided by the size of the knob 37 on the end of the arm 33 blocking the entrance to the slot or, as shown in FIGURE 3, by an additional plate 41 fixed to the arm 33, which plate covers the slot when the arm is in its inoperative position, i.e. its position shown in FIGURE 3. The arm may, if desired, be solenoid-operated, in which case a pair of buttons would be provided for moving the card support and the tie-bars.

Further safety means is also provided so that the card can only be inserted into the slot in one predetermined manner. These further safety means comprise a springloaded detent tor co-operation with a chamfer on one of the corners of the card. The sensing device is also provided with a light to show when a card is being sensed and there may be a further light which can be caused to operate when a card is not being sensed.

In operation of the sensing device, the arm 33 or the lever 32 is rotated in a clockwise direction (as viewed in FIGURE 3) to cause the tie-bars 30 to effect anticlockwise rotation of the movable ends 19 of the pins and to move the said ends of the pins. A card is then inserted between the ends 19 of the pins and the card support 14, which card trips the aforesaid locking mechanism of the sensing device. The arm 33 of the lever 32 is then allowed to return to its original position by or assisted by the spring 35. Hence the ends 19 of the pins move towards their original positions and the pins that sense a hole in the card will reach their original positions and these pins will hence make electrical connection with their associated contacts. The arm 33 of the lever 32 is then again rotated in a clockwise direction to allow the card to be removed. The removal of the card may be partially assisted by a cranked lever 42 located in the base of the slot 13 to expel the card into a position in which it can be gripped by the operator.

The invention is not restricted by the specific details of the device described above. For example, during assembly of the sensing device described above, it may be necessary to use shims to counteract any discrepancies in the sizes of the mouldings which may arise during manufacture thereof.

Also, the longintudinal axes of the pins 10 of the sensing device as described above lie in horizontal planes and the card to be sensed is inserted into a vertical slot 13. The device could, of course, be used in a position in which the longitudinal axes of the pins lie in vertical planes. In this case the slot 13 would be horizontal and the pins could be arranged either above or below the slot.

Furthermore, the switch described above has a pin 10 which, in its relaxed position, makes contact with the fixed contact 24 at point 29. However, in a modified construction (see FIGURE 5), the switch may be constructed, perhaps for use other than in a card sensing device, so that the flattened section 16 of the pin 10, when in its relaxed position, is out of engagement with the fixed contact 24. In this modified construction, a stop member 21a having the fulcrum point 22 is located adjacent the other surface of the section 16 of the pin 10. The position of the abutment 23 is also reversed so that the end 19 of the pin still passes between the stop member 21a and the abutment 23. Thus, in operation, when the free end 19 of the pin is flexed in the direction of arrow B, the pin will act against the surface of the stop member 21a and will deflect the flattened section 16 of the pin into engagement with the end 28 of the fixed contact 24 thereby closing the contact members of the switch.

I claim:

1. A device for sensing the holes in punched cards comprising a support for a card to be sensed, a switch for each station to be sensed, said switches each including a flexible blade having anchoring means at one end, a movable contact area inter-mediate the length of the blade, and a free end offset from the blade line for making contact with the card, a stop which engages one side of the blade and which is located between the movable contact area and the free end, and :a fixed contact member positoned adjacent to said contact area for engagement therewith, the blades of the switches being substantially perpendicular to a card on the card support with said free ends positioned to contact the card and sense the holes, and means for moving said free ends to flex the blades about the stops whereby said free ends have components of movement parallel to the card and also perpendicular to the card and whereby return movements of the blades which do not sense holes will be restricted by engagement with the card.

2. A device as claimed in claim 1 in which the card support is vertical and the blades are substantially horizontal.

3. A device as claimed in claim 1 in which the blades .5 6 are arranged in parallel rows, the means for flexing the 2,842,632 7/1958 Edwards. said free ends of the blades in each row being coupled 3,144,524 8/1964 Hawley et al. for operation in unison. 3,177,311 4/ 1965 Torrico 20047 4. A device as claimed in claim 3 in which the card 3,221,131 11/1965 Bury.

support is arranged to move in unison with the means for flexing the said free ends of the blades. 5 RO E SCHAEFFER, Primary Examiner.

References Cited D. SMITH, JR., Asszstant Exammer.

UNITED STATES PATENTS U.S. Cl. X.R.

2,567,552 9/1951 Cronin. 10 200-166; 235-6111

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