US3144761A

US3144761A - Lock release systems

Info

Publication number: US3144761A
Application number: US64543A
Authority: US
Inventors: Lee John Gwyn William
Original assignee: De Havilland Aircraft Co Ltd
Current assignee: De Havilland Aircraft Co Ltd
Priority date: 1959-11-04
Filing date: 1960-10-24
Publication date: 1964-08-18
Anticipated expiration: 1981-08-18

Description

XX JQLQQQIC].

1964 J. G. w. LEE I S 3,144,761

LOCK RELEASE SYSTEMS Filed Oct. 24, 1960 2 Sheets-Sheet 1 l4 l2 l0 4 Inventor F/G. a d

By K7,- LJ cQocJis Attorney Aug. 18, 1964 J. G. w. LEE Y 3,144,761

LOCK RELEASE SYSTEMS Filed on. 24, 1960 2 Sheets-Shet 2 llwenlor y g m FC, S

Attorney United States Patent 3,144,761 LOCK RELEASE SYSTEMS John Gwyn William Lee, Welwyn, England, assignor to The De Havilland Aircraft Company Limited Filed Oct. 24, 1960, Ser. No. 64,543 Claims priority, application Great Britain Nov. 4, 1959 18 Claims. (Cl. 70-277) This invention relates to lock release systems.

In the past, lock releases of safes and strong rooms have been operated mechanically by keys or combination dials. By the present invention, a lock release is operable by radiations, particularly infra-red radiations, and is less susceptible to successful interference than look releases heretofore.

According to the invention, therefore, a lock actuating system comprises a source of coded radiation pulses, a detector of radiation pulses and a comparator adapted to compare output signals of the detector with a preset sequence of signals and to operate the lock release upon completion of a correct sequence of radiation pulses.

The invention also includes, in a lock release system comprising a lock release operatively connected to a lock; a detector of radiation pulses associated with the lock, a comparator adapted to compare the output signals of the detector with a preset sequence of signals, and a portable source of coded radiation pulses arranged to be applied to said detector, said comparator being operatively connected to the lock release to operate the latter only upon completion of a correct sequence of radiation pulses from said source.

A further object of the invention is, in a lock release system comprising a lock release operatively connected to a lock; a detector of radiation pulses associated with the lock, a source of a preset sequence of signals, a comparator to compare output signals of said detector with signals from said source, a portable source of coded radiation pulses arranged to be applied to said detector, said comparator being operatively connected to the lock release to operate the latter to release said lock only upon coincidence of said output signals and said signals from said source.

Still further, the invention comprehends, in a lock release system, a detector of radiation pulses, a source of a preset sequence of signals, a comparator to compare output signals of said detector with signals from said source, a reset device operable to prevent operation of said lock release, a source of coded radiation pulses arranged to be applied to said detector, said comparator being operatively connected to said lock release and said reset device to operate said lock release upon coincidence of said output signals and said signals from said source and to operate said reset device upon lack of such coincidence.

In the accompanying diagrammatic drawings:

FIGURE 1 is a section of a key or source of coded radiation pulses;

FIGURE 2 is a broken front view of part of the key of FIGURE 1;

FIGURE 3 is a diagram of part of a detector of radiation pulses;

FIGURE 4 is an electrical circuit diagram of the detector;

FIGURE 5 is a diagram of the detector and comparator; and

FIGURE 6 is a front view of part of the comparator.

The lock release system consists of a detector release device within the safe and a key to operate the device. The key consists of a small infra-red source and chopper which sends out information in the form of radiation pulses, the wave length and sequence of which is coded.

These are applied to the detector release device which compares them with a standard coded set of pulses and if they are correct releases the lock.

The key 10 (FIGURE 1) comprises a battery operated lamp 12 which sends light through a stop and shutter 14 to fall on the edge of a rotatable chopper disc 16. The edge of the chopper disc 16 (FIGURE 2) is divided into a series of forty stations. At

alternate stations

17, 19, 21, 23, 25, termed dwell stations, the material of the disc is cut away to a predetermined extent. Between the dwell stations,

stations

18, 20, 22, 24, 26 termed pulse stations at which the material of the disc is either not cut away (stations 24 and 26) or is cut away to an extent twice that of the dwell station cut away (

stations

18, 20 and 22).

Light falling on the chopper disc 16 at the dwell stations passes through a predetermined area. At the pulse stations, light either passes through twice this area or does not pass at all. Light from the disc passes through a filter 30 which allows to pass only radiations within a predetermined range of wave lengths, for example 2.2 '[0 2.711.

The chopper disc 16 is rotatable in steps by a manually operable escapement drive 32. Each step brings another dwell station in front of the stop and shutter 14, so that during the stop light passes through a pulse station. The drive 32 is such as to ensure a maximum speed of the disc through pulse stations and to ensure at least a minimum period of time during transit of dwell stations.

The output of the key 10 is thus a steady amount of infra-red radiation interrupted by pulses either of a greater amount of radiation or no radiation. The exact coded sequence of pulses may be obtained by permanent removal of material from the disc or may be set by radially slidable shutters at the pulse stations.

In the wall of the safe is a disguised window 40 (FIG- URE 3) of germanium through which radiations from the key may fall on a detector 42 (FIGURE 5). Behind the window 40 and at 45 thereto is an optical filter 44 (FIGURE 3) which allows to pass only radiations within the predetermined range of wavelengths. These fall on a first radiation sensitive cell 46. Other radiations are reflected to a second radiation sensitive cell 48. The cells are lead sulphide cells and are connected in series with a resistor 50 (FIGURE 4) between an H.T. source and earth. The cell 48 is shunted by a resistor 52 and a tapping 54 is taken from between the cells to an amplifier 56 (FIGURE 5).

The cell 48 is so padded that when white light falls on the filter 44, the output signal from between the cells is zero. A signal from the tapping 54 is obtained only when the detector is illuminated with radiations of the predetermined range of wavelengths. In this case, the cell 46 is energised, and the cell 48 functions etfectively as a resistive load. The level of signal will depend on the amount of radiation received.

The amplifier 56 receives signals from the tapping 54 and differentiates these so as to provide an output of a negative signal pulse followed by a positive signal pulse when the incoming signal is zero, and a positive signal pulse followed by a negative signal pulse when the incoming signal is a maximum. The output pulses from the amplifier 56 are passed to a gating amplifier and sorter circuit 60 in which the second of each pair of incoming pulses is is eliminated and the first of each pair of incoming pulses is directed to one or other of two

output channels

62 and 64, in accordance with its sign, positive pulses to the channel 62 and negative pulses, after reversal, to the channel 64. The

channels

62 and 64 lead to a distributor circuit 66. The signals in the

channels

62 and 64 are directed either to channels 70 and a mm 7 72 or to

channels

72 and 74 by the distributor circuit 66 in accordance with coded signals received from an index pick-off 68.

Channels

70 and 74 lead to an escapernent release circuit 76 which upon receipt of a pulse, operates an escapernent 78 to permit a step rotation of a shaft 80. Channel 72 leads to a reset release circuit 82, which upon receipt of a pulse, operates a reset device 84 which over-rides the escapernent 78 and returns the shaft 80 to its initial position. The shaft 80 has an index disc 86 which has twenty

code stations

88, 90, 92, 94, 96, at each of which is a magnctised portion 98. The magnetised portion 98 at any particular code station may be close to the periphery (stations 94 and 96) or spaced therefrom (

stations

88, 90 and 92).

Each step of the shaft 80 brings another code station under the index pick-off 68 from which signals are derived from the distributor circuit 66, the signals being negative or positive in accordance with the position of the magnctised portion 98. The output of the pick-off 68 is thus a coded sequence of electrical signal pulses which is predetermined by the positions of the magnctised portions 98 on the disc 86 and agrees with the coded sequency of radiation pulses from the key 10.

The speed of the escapernent 78 is such that the step movement of the disc 86 from one code station to the next takes place in the period of time during which the chopper disc 16 remains on one dwell station.

The step movement of the disc 16 from one dwell station through a pulse station to the next dwell station takes place whilst the disc 86 remains on one code station. The shaft 80 carries a lock release 100 which after successful rotation of the shaft through twenty stations releases the safe lock (not shown).

The reset device 84 which resets the shaft is clockdriven to over-ride and prevent operation of the escapement 78 during predetermined periods of time, for example night and weekends.

In operation, the key 10 is presented to the germanium window 40 so that light from the filter 30 passes directly through the window. The battery operated lamp 12 is switched on 'and power from the electrical parts of the detector release device and for the drive to the shaft 80 is made available by a contact switch. At this time the index disc 86 is in a position in which the pick-off 68 lies over the code station 88 with the magnctised portion 98 spaced from the periphery, as shown in dotted lines in FIGURE 6. This results in a positive signal being applied to the distributor circuit 66 which thus directs incoming signals from the

channels

62 and 64 to the

channels

70 and 72.

The escapernent drive 32 is now manually operated so that the chopper disc 16 moves from one dwell station 17 to the next dwell station 19. During such move, the disc passes through the pulse station 18 in which light from the stop and shutter 14 passes through a full size cutaway, as shown in dotted lines in FIGURE 2.

This light passes through the

filters

30 and 44 to the cell 46 which produces an increased positive signal dur ing its exposure to the increased amount of radiation. This signal is differentiated in the amplifier 56 into a positive pulse signal followed by a negative pulse signal which pass to the gating amplifier and sorter circuit 60 where the negative pulse signal is eliminated and whence positive signal is directed to the positive channel 62. It is then directed by the distributor circuit 66 to the channel 70 and escapernent release circuit 76 to operate the escapernent 78, thus permitting the shaft 80 to rotate through one step.

The time delay in the circuit is such that this step is taken only when the chopper disc 16 has reached the dwell station 19. In its new position, the disc 86 is at the next code station 90 in which a positive signal is derived by the pickoff for the distributor. This directs signals from the

channels

62 and 64 to the

channels

70 and 72 so that if the key 10 continues to be operated a radiation pulse due to the cut away shape of the pulse station 20, causes a positive signal to pass and operate the escapernent 78.

This is again repeated for the next stations of the

discs

86 and 16.

In the code station 94, however, the pick-off 68 lies over a magnctised portion 98 adjacent the periphery of the disc 86 and a negative signal is applied to the distributor circuit 66 so that the latter directs incoming signals in the

channels

62 and 64 to the

channels

72 and 74.

As the disc 16 passes from the dwell station 23 to the dwell station 25, the passage of light is blocked by the material of the pulse station 24. This results in a zero signal from the cell 46, so that a negative pulse signal followed by a positive pulse signal is derived from the amplifier 56 after removal of the positive signal and passed by the gating amplifier and sorter circuit 60 to the channel 64 and by the distributor circuit 66 to the channel 74 to energise the release circuit 76 to operate the escapement 78.

Coded pulse signals continue to operate the escapernent 78 so long as the radiation pulses coded by the disc 16 agree with the signals derived from the pick-off 68 and coded by the disc 86. After twenty correct signals have been received, the lock is released.

If at any time an incorrect radiation pulse is received, the resultant pulse signal is directed by the distributor circuit 66 to the channel 72 so that the reset device 84 is operated by the circuit 82 and the lock is not released. An alarm may be initiated at the same time.

It will be understood that the wavelength of the radiation pulses used need not be that stated, but is preferably within the infra-red range as radiation sensitive cells for this range are available. For the sake of simplicity it is also desirable to keep the wavelength within the near-visible range of wavelengths.

Instead of magnetised portions, the disc 86 may carry contacts for engagement by a pick-off, and from which signals of opposite polarity could be obtained.

The comparator circuit in which signals from the detector are compared with signals from the driven disc 86 may differ from that described. For example the polarity of certain signals from the amplifier may be reversed in the distributor circuit 66 instead of in the sorter cirter. Alternatively the signals from the amplifier 56 may be directed unsorted to a distributor and thence to two sorter circuits.

The index disc pick-off is described as producing negative and positive signals, but it will be understood that signals of the same polarity may be produced in one of two different channels to control the distributor. Alternatively either one or two signals may be produced by the pick-off depending upon the particular code station.

It will be appreciated that with forty stations, the chopper disc gives a code of twenty digits with over 1,000,000 combinations. If less or more combinations are required, less or more stations are used.

Before presentation of the key to the window, the index disc may be in a position of rest and upon such presentation be moved up to the correct position for the first pulse. In this case the chopper disc may have a blank starting portion on its periphery between the first dwell station and the last pulse station.

I claim:

1. A lock release actuating system comprising a substantially steady source of radiation, an angularly movable chopper arranged to vary the amount of radiation passing from said source to produce a predetermined sequence of radiation pulses, a detector of radiation pulses, and a comparator operable to compare output signals of the detector with a preset sequence of signals and to initiate a v lock-releasing operation upon completion of a correct seincluding an escapement by which the chopper is movable stepwise.

3. A lock release actuating system as claimed in claim 2, wherein the chopper has dwell portions which allow a predetermined amount of radiation to pass, and pulse portions between said dwell portions, which allow different amounts of radiation to pass in a predetermined sequence.

4. A lock release actuating system as claimed in claim 3, wherein the chopper is in the form of a disc having dwell portions of one diameter and pulse portions of a diameter chosen from two diameters, one greater than and the other less than said dwell portion diameter.

5. A lock release actuating system as claimed in claim 4, wherein the pulse portions comprise shutters radially movable between positions corresponding to said diameters.

6. A lock release actuating system as claimed in claim 2, wherein the escapement is manually rotatable.

7. A look release actuating system comprising a detector of radiation pulses, a comparator adapted to compare the output signals of the detector with a preset sequence of signals, and a portable source of a predetermined sequence of radiation pulses arranged to be applied to said detector, said portable source including a substantially steady source of radiation and an angularly movable chopper arranged to vary the amount of radiation passing from said steady source to produce said sequence of radiation pulses, and said comparator being operatively connected to initiate a lock-releasing operation upon completion of a correct sequence of radiation pulses from said portable source.

8. A system as claimed in claim 7, including an escapement by which the chopper is movable stepwise.

9. A system as claimed in claim 8, wherein the chopper has dwell portions which allow a predetermined amount of radiation to passs, and pulse portions between said dwell portions, which allow difierent amounts of radiation to pass in a predetermined sequence.

10. A system as claimed in claim 9, wherein the chopper is in the form of a disc having dwell portions of one diameter and pulse portions of a diameter chosen from two diameters, one greater than and the other less than said dwell position diameter.

11. A lock release actuating system comprising a detector of radiation pulses, a source of a preset sequence of signals, a comparator to compare output signals of said detector with signals from said source, and a portable source of a predetermined sequence of radiation pulses aranged to be applied to said detector, said portable source including a substantially steady source of radiation and an angularly movable chopper arranged to vary the amount of radiation passing from said steady source to produce said sequence of radiation pulses, and said comparator being operatively connected to initiate a lock-releasing operation only upon coincidence of said output signals and said signals from said source of a preset sequence of signals.

12. A system as claimed in claim 11, including an escapement by which the chopper is movable stepwise.

13. A system as claimed in claim 12, wherein the chopper has dwell portions which allow a predetermined amount of radiation to pass, and pulse portions between said dwell portions, which allow difierent amounts of radiation to pass in a predetermined sequence.

14. A system as claim in claim 13, wherein the chopper is in the form of a disc having dwell portions of one diameter and pulse portions of a diameter chosen from two diameters, one greater than and the other less than said dwell portion diameter.

15. In a lock release actuating system, a detector of radiation pulses, a source of a preset sequence of signals, a comparator to compare output signals of said detector with signals from said source, a reset device operable to prevent any lock releasing operation, a source of coded radiation pulses arranged to be applied to said detector, said comparator being operatively connected to the reset device and connected to initiate a lock releasing operation upon coincidence of said output signals and said signals from said source and to operate said reset device upon lack of such coincidence.

16. A system as claimed in claim 15, wherein the source of the preset sequence of signals includes an angularly movable member from which the sequence is derived, said comparator being arranged upon coincidence to pass said output signals to drive said angularly movable member in one direction and upon lack of coincidence to pass said output signals to said reset device to drive said angularly movable member in the other direction, said angularly movable member being operatively connected to initiate a lock releasing operation upon completion of angular movement on said one direction.

17. A system as claimed in claim 16, wherein the angularly movable member is movable stepwise.

18. A system as claimed in claim 17, including an escapement to drive the angularly movable member in said one direction arranged to be released by the receipt of output signals from the comparator.

References Cited in the file of this patent UNITED STATES PATENTS 1,923,968 Chase Aug. 22, 1933 2,008,150 Nelson July 16, 1935 2,499,889 Teichmann Mar. 7, 1950 2,677,814 Miller May 4, 1954 2,779,874 Sonborgh Jan. 29, 1957 2,909,711 Neville et a1 Oct. 20, 1959 2,936,607 Nielsen May 17, 1960

Claims

1. A LOCK RELEASE ACTUATING SYSTEM COMPRISING A SUBSTANTIALLY STEADY SOURCE OF RADIATION, AN ANGULARLY MOVABLE CHOPPER ARRANGED TO VARY THE AMOUNT OF RADIATION PASSING FROM SAID SOURCE TO PRODUCE A PREDETERMINED SEQUENCE OF RADIATION PULSES, A DETECTOR OF RADIATION PULSES, AND A COMPARATOR OPERABLE TO COMPARE OUTPUT SIGNALS OF THE DETECTOR WITH A PRESET SEQUENCE OF SIGNALS AND TO INITIATE A LOCK-RELEASING OPERATION UPON COMPLETION OF A CORRECT SEQUENCE OF RADIATION PULSES.