Patent GB-190113408-A (GB)
Title: Improvements in Apparatus for Automatically Producing a Constant Air Pressure in Pneumatic Tyres
Inventor: NIELSEN CARL
Filed: 1901-07-01
Granted: 1902-01-16
Abstract: 13,408. Nielsen, C., Andersen, A. C., and Andersen, L. S. Dec. 1, A.D. 1900, [date applied for under Sec. 103 of Patents &c. Act, A.D. 1883], Wheels with air-compressing appliances; hubs.- Relates to means for producing a constant air pressure in pneumatic tyres by apparatus operated by the motion of the vehicle, The form shown in detail section in Figs. 1 and 2 consists of a cylinder b, which is secured to the wheel hub a and which is provided with a piston d pressed outwardly by the conical spring e. The outer end of the piston-rod is connected to a plate m, which is pivoted to a lever n and bears against a roller p mounted on the fork o. As the wheel rotates, the piston oscillates, and compresses air through the tube g, chamber v, and tube h into the tyre. The chamber v also communicates with an airtight, extensible bag q, which can expand in the metal casing r, so as to move the spring-controlled pin s into a depression in the piston-rod c. The apparatus is thus thrown out of action when a predetermined air pressure is reached, and is automatically re-started at any lower air pressure. The maximum air pressure is controlled by adjusting the spring t which bears on the pin s. The cylinder may be placed so that the piston-rod C is radial, in which case it may be operated either from an eccentric plate fixed to the axle or from a crank rotated by friction wheels. In the modification shown in section in Fig. 15, the piston-rod c has an external re-current groove w, in which moves a lug 8 on a sleeve 9 rotated by means of the gear-wheels 10, 12, of which the latter 12 is secured to the fixed axle 28. As the air pressure increases, the extension of the bag q operates the hook 2, and so moves the wheel 10 out of gear with the wheel 12. When the piston-rod c is parallel to the axle 28, the groove w may be in the form of a screw, in which case the wheel 10 is rotated first in one. direction and then in the other by securing to the axle 28 a gear-wheel 4, Fig. 7, which is toothed externally on part of its periphery and internally on another equal part. In the form shown in section in Fig. 18, the hub a is lined with the cylinder b, on the inner part of which moves the tubular piston-rod c. The sleeve 36 slides with the piston d, and is prevented from rotating by a projection 43, which takes into a groove 42 in a casing 41 fixed to the axle 28. The sleeve 36 has an external groove 39 with which engages a pivoted projection 40, so that, as the wheel rotates, the piston oscillates until the desired air pressure is obtained, when the extension of the bag q moves the projection out of the groove 39, and so throws the apparatus out of action. In the form shown in section in Fig. 21, a separate axle is dispensed with, and the extensions 52, 53 of the hub a rotate in ball bearings mounted in the ends of the forks 55, 54. The hub forms the cylinder in which oscillates the piston d connected to a sleeve 36 having an internal groove 39. The fixed arm 65, secured to the fork 54, has a spring-pressed projection 40, which engages in the groove 39 so that, as the wheel rotates, the piston oscillates until the desired air pressure is obtained, when the distension of the bag q operates the levers 69 to draw the projection out of the groove, and to throw the apparatus out of action. Guide rods and plates for the pistons and piston-rods may be employed.