US3077967A

US3077967A - Safety switch for mechanized files

Info

Publication number: US3077967A
Application number: US842086A
Authority: US
Inventors: Benjamin W Woodward; Walter G Anders
Original assignee: Sperry Rand Corp
Current assignee: Sperry Corp
Priority date: 1959-09-24
Filing date: 1959-09-24
Publication date: 1963-02-19
Anticipated expiration: 1980-02-19
Also published as: BE595339A; GB938687A; CH403712A

Description

Feb. 19, 1963 B. w. WOODWARD ETAL 3,077,967

SAFETY SWITCH FOR MECHANIZED FILES Filed Sept. 24, 1959 3 Sheets-Sheet 1 BENdAM/N W WOODWARD WALTER G. ANDERS ATTORNEYS Feb. 19, 1963 B. w. WOODWARD ETAL 3,077,957

SAFETY SWITCH FOR MECHANIZED FILES Filed Sept. 24, 1959 3 Sheets-Sheet 2 FlG.3

RESET (Rs) MA CH/NE FRAME\ /1;

INVENTORS BENJAMIN W- WOODWARD WALTER W ANDERS BYZZI I fiMJ-W A TTORNEYS Feb. 19, 1963 B. W. WOODWARD ET AL SAFETY SWITCH FOR MECHANIZED FILES Filed Sept. 24, 1959 3 Sheets-Sheet 3 POSITIVE (RED) COMMUTATOR ASSEM.

. u-4L u-3 W- J SPuc 5TR(B)$TR(4 D4 SPLICE $TR(B)-/ sTR(AJ-2 M 0-3 I, SHUNT P I FIELD s L c5 5 FPS a FPS 1 s a Ps- 9 cs 9 Bil 5 BR Hcs \J PILO7TRED PILO') RE CT-l NE 6- (BLACK) 1 T0 //5 VOLT i I 60 CYCLE AC C CT BREAKER I POWER SOURCE -o \-o l WIRE CL IPMVU/WV/V SCR E W3 INVENTORS BENJAMIN W WOODWARD WALTER G. ANDERS A T TORNE Y5 surfaces.

3,077,367 SAFETY SWiTCH FGR MEQHANIZED FILES Benjamin W. Woodward and Walter G. Anders, Kenmore, N.Y., assignors to Sperry Rand Corporation, New York, 'N.Y., a corporation of Delaware Filed Sept. 24, 1359, Ser. No. 842,086 7 Claims. (Cl. 192--130) This invention relates to mechanized files and more particularly to an endless conveyor file having a plurality of card trays mounted to travel in an endless vertical path within the file casing. In devices of this type the trays are moved to a reference position wherein the tray desired is disposed in front of the operator at an open upper portion of the file casing.

The main object. of the invention is to. provide a simple, efiicient and economical construction of switch which is located adjacent the reference position sothat the machine is stopped whenever the hand of the operator comes in contact with the switch bar especially when the trays are in motion. This is obviously to prevent injury to the hand of the operator if it is extended too far into the casing, especially when the trays are in motion.

A further object is to provide a simple circuit arrangement which will efifect the stoppage of the motor and will prevent itstarting again until the circuit is deliberately reestablished.

Extensive search and study has disclosed the urgent need to devise a safety device which would offer optimum protection to operators of mechanized files of this type. Existing devices had size, distance,-and directional limitations which, even when extensively modified, would not answer the purpose. 1 I

Guided by the theoryof simplicity, we have developed a 'new and unique device to achieve the above objects. Basically this inventioninvolves a'grounded cable disposedunder tension closelyadj'acent one or more charged In a particular form the cable is centered within slightly oversize holes in electrically charged .plates- .-Any contact-made between the cable and the plates will result in quickly stopping the machine through the intermediary of associated contacts and circuit relays and connections. Preferably the cable is held in a taut line by a constant spring pressure by specific means later described.

The simplicity of construction and operation of this device results in a high degree. of reliability. The grounded cable being fully encircled will operate when the slightest pressure is applied from any direction. This safety mechanism overcomes the length limitations normally encountered in other devices, and. operates with equal sensitivity along its entire length.

The present preferred form of the invention is illus- 'trated in the drawings, of which,

FIG. 1 is a partial perspective view of the top of a file casing with the upper front cover removed to show the trays therein in the reference position and with the safety switch in position with respect thereto;

FIG. 2 .is a perspective exploded view of the details of the'switch and its mounting;

' FIG. 3 is aview showing the local circuit involving the safety switch; and

FIG. 4 is a view showing the circuit for the entire mechanized file including the safety switch.

In FIG. 1 is shown the file casing 30 with the upper front cover removed to expose the trays 32 in the socalled reference position 31 where the trays and their contents are available to the operator either for examination or removal of the trays. It is understood that, in accordance with well known practice, these trays are mounted on conveyor means which moves them either up or down in an endless path and that, upon actuation Patented Feb. 19, 19133 of proper buttons or similar devices, designated trays may be thus presented. The

side portions

33 and 34 of the casing form chambers within which are housed the specific means for supporting the safety switch.

As shown the safety switch includes an elongated substantially rigid tubular element 35 of insulating material constituting a manual pressure bar extending between the

side portions

33 and 34 of the casing and across in front of the reference position as shown. This element 35 embraces an elongated bare wire 36 of conductive material which extends between

bracket members

37 and 38 disposed within the

side portions

33 and 34 of the casing. The

bracket members

37 and 38 are suitably grounded on the casing of the machine. The wire 36 passes through an opening 39 in the bracket 38 and is fixed to the bracket 38 in any suitable manner not shown. At the other end the wire is connected to a slideable metallic stem 40 movable within a sleeve 41 in the bracket 3-7. The stem has a headed portion 43 between which and the sleeve 41 is disposed a coiled spring 42 which tends to stretch the wire 36 and hold it under desired tension to maintain it taut.

As shown in FIG. 2 there is an insulated block 44 bolted to the corner of the side portion 34 and there is a similar block similarly fixed to the corner of the side portion 33 but not shown in FIG. 2. To these blocks 44 are respectively fastened

conductive plates

45 and 46. These

plates

45 and 46 are connected in circuit in a manner to be explained later. Each plate is provided .with an aperture 47 through which the wire 36 passes but not normally in contact therewith. A slit 48 extends from the aperture 47 in each plate to the adjacent edge thereof. The portion of the plate beneath the slit may be bent aside suflicient to permit the wire 36 to he slipped into the aperture 47 and then moved back to close the opening thus formed.

This constitutes the main feature of the invention and it is obvious that if the operator is careless in extending his hand into the opening in the casing, especially when the trays are in motion, he may suffer considerable injury. However if his hand makes even the slightest contact with the tube 35 the wire 36 will be moved to make contact with the

plates

45 and 46 with the result that the motor of the device will be stopped in a manner now to be described.

As shown in FIG. 3, the actuating circuit of the safety switch consists of a relay BR having a low voltage mag netic coil, a pair of normally closed contacts BR-l operated by relay BR and connected in series with the magnet coils of the motor-control relays U and D; a set of transfer contacts having normally closed contacts BR-Z in series with a green pilot light, shown in the complete electrical diagram of FIG. 4, and normally open contacts BR-3 connected from one terminal of a low voltage transformer for example, 6 volts through a reset switch RS to terminal 9 of the BR magnet coil. There is a pair of normally open contacts U-2 operated by the magnet coil of relay U and a similar pair of contacts D-Z operated by magnet coil of relay D, said last named contacts being connected in parallel so as to form part of the series electrical circuit (when closed) from a terminal of the transformer through the safety switch contacts (when closed) through closed contacts U-Z or D-2 to relay BR and back to the other side of the transformer. The holding circuit consists of a pair of normally closed contacts RS forming part of a series circuit from terminal 6 of the transformer through RS, normally open contacts BR-3 (when closed) and relay BR magnet coil to terminal 7 of the transformer.

The indicator or pilot light circuit consists of a circuit from terminal 6 of the transformer through switch RS,

d normally closed relay contacts BR-Z and through the green light to terminal 7 of the transformer.

Operation of the Device FIG. 4 shows a typical complete circuit for a machine of this kind, and includes the safety switch described with respect to FIG. 3. In FIG. 4 the safety switch is indicated by the letters FSS. Since we are not concerned with all the details of the complete circuit, it will only be described in general and only particularly in respect to how the safety switch affects it. When the device isready for operation the upper front panel is opened as-shown in FIG. 1 thus exposing the card trays which are in the reference position as well as the safety switch as shown. If it is desired to move the trays in the lip-direction a start button and'the up button are pressed which will energize the motor and close the contacts U-Z o f'the relay U. This will establish a circuit through relay BR up to the safety switch FSS. When the machine is ready to start all the auxiliary interlock switches FPS, BPS, CS, F85, and HCS are open. With the machine at rest contacts U-2 and D-2 on the corresponding relays are open, as are contacts B-1 and Zen relay BR since there is no closed electrical path from one side of the transformer secondary through magnet coil BR to the other side of the transformer. However, relay contacts BR-2 are closed and thus the green light is lit by connection from terminal 7 of the transformer through the lamp, contacts BR-2, reset contacts RS to terminal 6 of the transformer.

When the conveyor is operated in either direction, down or up, by depression of the appropriate buttons, relay contacts D-2 or U-Z respectively are closed. If, during this operation period, contacts FSS of the safety switch are closed by the operators hand a closed electrical circiut will exist from terminal 6 of the transformer, through safety switch contacts FSS, closed contacts U-2 or D-2 and BR magnet coil to terminal 7 of the transformer. The magnet BR coil being energized will cause normally closed contact BR-l to open, thus removing electrical power from the magnet coil of relay U or D. This will deenergize the motor and apply dynamic braking to instantly stop the apparatus. Actuation of the magnet coil BR also causes norr'n'ally closed contacts BR-2 to open, thus causing the green light to be extinguished. Also, normally open contacts BR-3 are caused to close, completing an electrical circuit from ter' minal 6 of the transformer through reset switch RS, contacts BR-3 and relaymagnet coil BR to terminal 7 of the transformer. Thus relay BR is held in actuated condition through its own contacts until such time that the reset switch RS is manually opened. The electrical holding circuit is then disrupted and the relay BR reverts to normal deenergized condition.

While the invention herein has been fully described in detail with respect to a present preferred form which the invention may assume, it is not to be limited to the specific form shown since changes and modificatoins may be made in the structure and parts without departing from the spirit and scope of the invention in its broadest aspects. Hence it is desired to cover any and all forms and modifications of the invention which may come Within the spirit and scope of any one or more of the appended claims.

What we claim as our invention, is:

1. A safety device for a mechanized file wherein a pinrality of trays are moved by a motor and motor controlled circuit meansiwithin a casing provided with an opening permitting access to the trays, comprising a grounded wire extending across the opening, yieldably adjustable means for holding the wire taut, and an electrically charged plate in said circuit means disposed closely adjacent said Wire for deenergizing the motor control circuit to stop the motor when said wire is moved against the resistance of said holding means and into contact with said plate.

2. The safety device of claim 1 in which the charged plate has an opening through which the wire passes but out of contact with the edge of said opening.

3. A safety device for a mechanized file wherein a plurality of trays are moved by a motor and motor controlled circuit means within a casing provided with an opening permitting access to the trays, comprising a grounded wire associated with said circuit means and extending completely across said opening, adjustable means for yieldably holding said wire taut, a substantially rigid manual pressure bar extending the length of the wire in said opening and constituting an insulating sleeve for said wire, and a plurality of electrically charged plates associated-with the circuit means-and' disposed closely adjacent said wire and arranged in-spaced'relation therealong for deenergizing the mot-or'control circuit to stop the motor when said wireris moved against the resistance of said holding means and into contact with n plate.

4. The safety deviceiof claim 3 in which the charged plates each have an opening through which the wire passes but normally out of'contact wtih the edges thereof.

5. The safetydevice of claim 3 in which the casingincludes side portions at opposite ends of the opening, the wire.v extending into said side portions, the adjustable yielding means for holding t-hewire taut being disposed in one of said side portions, each of saidplates having an opening larger than the diameter of the wire and through which the wire passes and said openings being slotted to provide means for initially positioning thewirc in said openings.

6. Safety switch means for a mechanizedfile having a casing having an opening in which trays of cards are moved by a circuit controlled motor, a conductive wire extending across said opening, a substantially rigid manual pressure bar extending the length of the wire in said opening and constituting an insulating sleeve for said wire, oppositely spaced charged plates each'having an opening through which the wire passes without contacting the same, yieldably adjustable means for holding the wire taut for free passage through said plateopenings, relays withcontacts to close the. motor circuit when operated, a control relay in circuit with said contacts when they are closed, said control relaybeing energized when the conductive wire contacts acharged'plate, and a contact operated by the control relay and in circuit with the first mentioned relays to open the circuit of said relays and open the motor control circuit.

7. The safety switch means of claim 6 including a pilot 2 light normally in circuit with another normally closed contact of the control relay and still another normally open contact controlled by the control relay to establish a holding circuit for said control relay when the last mentioned contact is closed, and a reset switch normally closed and in said holding circuit, said reset switch when opened breaking the holding circuit and permitting the relays-and contacts to restore to normal condition.

References Cited in thefile of this patent- UNITED STATES PATENTS OTHER REFERENCES The Remington-Rand Conve-Filer Pamphlet, March 1952, page 3.

Claims

1. A SAFETY DEVICE FOR A MECHANIZED FILE WHEREIN A PLURALITY OF TRAYS ARE MOVED BY A MOTOR AND MOTOR CONTROLLED CIRCUIT MEANS WITHIN A CASING PROVIDED WITH AN OPENING PERMITTING ACCESS TO THE TRAYS, COMPRISING A GROUNDED WIRE EXTENDING ACROSS THE OPENING, YIELDABLY ADJUSTABLE MEANS FOR HOLDING THE WIRE TAUT, AND AN ELECTRICALLY CHARGED PLATE IN SAID CIRCUIT MEANS DISPOSED CLOSELY ADJACENT SAID WIRE FOR DEENERGIZING THE MOTOR CONTROL CIRCUIT TO STOP THE MOTOR WHEN SAID WIRE IS MOVED AGAINST THE RESISTANCE OF SAID HOLDING MEANS AND INTO CONTACT WITH SAID PLATE.