Patent GB-189921403-A (GB)
Title: Improvements in Protective Devices against Burglary.
Inventor: PETTERNEL AUGUST
Filed: 1899-10-26
Granted: 1900-10-26
Abstract: 21,403. Petternel, A. Oct. 26. Alarms, burglar and like.-Relates to means for protecting apartments, safes, moneychests, and the like from burglary. The money-chests &c., or the doors, windows, walls, &c. of apartments, are covered with an arrangement of plates, such as shown in Fig. 4. The plate 3 is formed on both faces with two series of grooves 1. The two series are independent, but each series on one face communicates through the channels 4 with the corresponding series on the other face. The plate 3 is enclosed between the external and internal cover-plates 6, 7, the plate 7 having channels 8, Fig. 5, communicating with one series of passages, and channels 9 communicating with the other series. The groove 10 in the plate 7 is divided by the packing 34, and communicates through the grooves 11, 12 with the channels 8, 9 respectively. The third groove 13 from the groove 10 communicates with the channels 17, 18 on the plate 14, Figs. 4 and 7, the grooves 23, 24 connecting the channels 17, 18 with the channels 15, 16, which register respectively with the channels 8, 9. Each plate 7 has contacts 29, 31 connecting respectively with corresponding contacts 31, 29 on adjacent plates. These contacts are connected by wires 30, lying in the channels 10, 13, 17, 18, with the contact-terminals 33 in the arms of the U-tube 22, Fig. 7, which contains mercury. The arms of the U-tube are made of glass, and the bend of metal, the bend being connected by the wire 32 with the base-plate 73, Fig. 10, of the apparatus. By means of the valves 21 controlling the passages 19, 20, Fig. 7, air can be admitted to or withdrawn from the series of passages in the plates. In setting the apparatus, the pressure of the air within the passages is adjusted so that it is greater or less than the external pressure, and so that the mercury stands at different heights in the arms of the U-tube 22. On an attempt to drill or fracture the plates, the pressure is equalized, and the mercury makes contact with one or other of the terminals 33, so completing the alarm circuit. Any suitable alarm apparatus may be employerl. In the arrangement shown in Figs. 10, 11, and 12, the apparatus is enclosed in the safe &c. to be protected, One pole of the battery 28 is connected to the base-plate 73, and the other pole is connected through the lead x with one of the contacts 29. Fig. 12 shows a gas generator for operating an alarm whistle, Fig. 11 a contact-mechanism connected with the lock bolt 47 for giving the alarm in case of unauthorized opening of the lock, and Fig. 10 a controlling-mechanism which enables an authorized person to open the lock witbout sounding the alarm. The vessel 37, Fig. 12, contains sodium bicarbonate or similar material, and the vessel 38 contains sulphuric acid &c. The opening 40 of the vessel 38 is closed by wax. When the electromagnet 64 is energized, it releases the armature catch 68 from the clock-train 41<c>, so that the stud 41<a> allows the spring-controlled lever 41<d> to force the bolt 41 downward to break the wax 40. When the lever 41<d> passes the stud, with which it engages, on the bolt 41, the latter is returned by the spring 41<f>, the aperture being closed by the flap valve 42. When the wax is broken, the acid &c. is discharged through the nozzle 39 on to the material in the vessel 37. The carbonic acid or other gas generated sounds a signal whistle connected to the pipe 36. To obtain a suitable gas pressure, a membrane, adapted to break at the desired pressure, may be placed in the pipe 36. This pipe may be surrounded by air tubes 43 connected to the U-tube 22, as shown in Fig. 15, so that, if it is attempted to cut the pipe 36, the tubes 43 will also be cut and cause the alarm to be sounded. The lock bolt 47 has a pendulum 48, which connects with the fixed contacts 44, 45 in the alarm circuit when the lock is opened. In the controlling-apparatus, Fig. 10, two number wheels or discs 49, 50 are provided, which can be set to any desired position. To permit the opening of the lock without sounding the alarm, the discs must be returned to the position shown, in which position the recesses 51 in the discs are aligned. This movement of the discs is effected step-by-step, by ratchet mechanism actuated by the electromagnets 56, 57. The circuits of the magnets are completed separately the desired number of times by means of the switch 53 and the contact-key 52. When set as shown, the opening of the lock 47 closes, at the contacts 44, 45, the alarm circuit through the battery 28 and electromagnet 58. This causes the armature 59 to release the pivoted arms 60, 61, the arm 61, however, being caught by the arm 62, the projection 63 of which rests in the notches 51. In this case the alarm is not sounded. If the discs 50, 51 are not properly set, the arm 62 is held clear of the arm 61, in which case the arms 60, 61 will fall until the plate 65 connects the contacts 66, 67, so completing the circuit of the alarm-operating electromagnet 64. The discs 50, 51 cannot be actuated unless the arms 60, 61 are set in the proper position, as shown, for, if the arms have fallen, the circuits of the electromagnets 56, 57 are broken between the contacts 71, 72.