171 Exhausting Air from Tubes ^ S)C, 



13 



piston, the springs being first rivetted on such plates. I con- 

 struct and pack the upper and under sides of the piston in a 

 respectively similar manner. The construction and packing 

 of the piston will be more readily understood by the 

 drawing or plan, sheet No. III., figures 7? and 8, in which 

 A, represents the main portion of the piston, which may 

 be of cast iron; b, b, the continuous bands of leather ; 

 c, c, c, c, the plates by which the leather is fixed on the 

 piston by a convenient number of screws, or screw-bolts, 



6?, d; E, fig. 8, represents the plate of thin steel after being 

 cut for forming the springs, and r, the same plate after 

 the springs have been bent upwards ; such springs are 

 rivetted to the plates, c, c, and are shown in position 

 at G, G, G . The smaller plates, h, h, k, are removable 

 independently of the plates, c, c, c, c, in order to permit 

 the insertion of a suitable bent tool or tools for the pur- 

 pose of forcing out the band of leather when partly worn 

 so as to present a fresh surface to the cylinder, the space 

 left by the leather being afterwards filled up with pieces 

 of wood, or other suitable material, so as not to leave any 

 undue space for air. 



First, I claim the so arranging apparatus or gearing 

 with the valves of air-pumps, as to close the outlet valves 

 but not to open them, the gearing leaving such valves at 

 liberty to open when relieved from the pressure of the 

 air. 



Secondly, I claim the so combining vessels or reservoirs 

 with air-pumps in working atmospheric railways that the 

 air may be pumped from the traction-tubes of atmospheric 

 railways into partially exhausted vessels or reservoirs, 

 and, when desired, the pressure of the air passing from 

 such traction-tubes into such partially exhausted vessels 

 or reservoirs may be used for giving motion to air-pumps. 



Thirdly, I claim the mode of packing pistons of air- 

 pumps as herein described.^ — In witness, &c. 



William Sykes Ward. 



Enrolled December 24, 1845. 



Macintosli, Printer, Great New-street, London. 



