Patent GB-368431-A (GB)
Title: Improvements in pressure gauges and deflation indicators more especially for pneumatic tyres
IPC: B60C23/04
Filed: 1930-12-19
Abstract: 368,431. Pneumatic tyres. HENRY, L., 40, Rue Trebois, Levallois-Perret, Seine, France. Dec. 19, 1930, No. 38341. Convention date, Dec. 26, 1929. [Class 144 (i).] . Deflation, indicating.-Comprises particular constructions of combined deflation indicators and pressure gauges for pneumatic tyres. The inner tube of the tyre is clamped between a hollow screw 49 and a valve head 48 on a tube 57 screwed at the other end for connection to a source of fluid pressure supply. The tube 57 is located within an outer tube 59 provided with windows 58 through which indicating marks on the tube 57 are visible. Bent leaf springs 50, 501 have their ends connected to the tubes 57, 59 and tend to force them apart. The lower part of the tube 59 is grooved to accommodate the teeth of a transparent nonconducting sleeve 53 covered with an apertured conducting sheath 54. A nut 55 of insulating material holds the sleeve 53 in place and is provided with a conducting sheath 56 which presses on the sheath 54 but does not contact with the earth to complete the circuit until the crown 61 of the valve plug 62 presses on the sheath 56 due to the deflation of the tyre. The plug 62 engages with a rubber plate 18. The valve cap 63 screws on to the sheath 54. The tube 57 has a red mark which appears at the window when pressure is too low and a white mark if sufficient. The pressures may also be read on a scale. In a modification, the inflating valve is omitted and in this case the inner tube is not pierced and may be changed without removing the pressure-indicating device. The electric alarm circuit comprises a brush located in the wheel hub and connected to the terminal at the end of the valve cup 63, the brush bearing against an insulated ring connected to one pole of a battery the other pole of which is earthed through a switch and the signal device. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the following constructions. In the form shown in Fig. 1 (Cancelled) an inflating valve 1 rests on a seating 4 in a tube 5 adapted to be coupled to a pump. The upper end of the tube 5 is provided with longitudinal grooves 6 which mesh with long teeth formed by grooves in a sleeve 8 the top end of which has teeth engaging teeth in the end of a tube 11. The sleeve 8 is held against the tube 11 by a sheath 12 screwed on the tube 11 and provided with a shoulder engaging a shoulder on the tube 8. Windows 13 are formed in the sheath 12. An extension 7 of the sleeve 8 has fixed over it a cap 15 of insulating material fitted with a sheath 16 of conducting material which extends over the lower edge of the extension. Fitting over one end of the tube 5 is the valve plug 17 within which is a rubber plate 18 and screwed head 19 so that when the plug is tight the upper end is normally clear of the sheath 16. The tube 5 screws on to a tube 20, packing 21 making a tight joint. The tube 20 is provided with two longitudinal ribs 10, 10<1> engaging grooves in the tube 11, and is connected to the outer end of a flexible capsule 22 open to tyre pressure and connected at the inner end to the head 24 of the tube 11. This is fixed to the inner tube of the tyre which is clamped between the head 24 and a washer 32 by a nut 33, the hole in the washer being hexagonal to engage a similar shaped part of the tube which is thus prevented from turning. The indicator consists of a washer 25 and light cylindrical member on which red and white bands are painted. The ends of the ribs 10, 10<1> bear against the washer between which and a washer 28 is a spring 27. The washer 28 rests on the tube 8. A valve cap 29 provided with a terminal 30 is screwed over the sheath 16. In use, the tyre is inflated until the minimum pressure is exceeded when the spring 27 yields and the tube 20 is pushed into the tube 11, the indicator 26 following. The red band which is exposed at the window 13 is moved below the window until only the white band is seen, when the tyre is sufficiently inflated. The electric alarm circuit, which was closed, is opened by the parts 16, 17 disengaging as soon as the tube 20 starts to move. This circuit is the same as that described above. In a modification, the ,expandable tube 22 is replaced by a diaphragm'. In a further form, the expandable tube is located more or less centrally of the length of the device and is acted upon by a spring to compensate for centrifugal force. In a final form, the signal valve is adapted for fixing to valve tubes actually in use. In this form, the expansible tube is of rubber surrounded by a spring. This subject-matter does not appear in the Specification as accepted.