710 



CAOUTCHOUC 



Hodge's compound spring is designed to obviate the frequent breakage of tho steel 

 springs on locomotive engines. Fig. 413 shows one of these springs ; a block of 

 India-rubber is placed on each end of the steel spring, or is suspended under the engine 

 frame ; they are in use on several of the English railways, and are said to answer tho 

 purpose intended well. 



Scott a patent (see fig. 414), dated May 1856, consists in the use of blocks of India- 

 rubber, or cones, placed over the centre of the spring ; they are to obviate the danger of 



414 



overloading carriages and trucks, a frequent source of danger to the springs, and are 

 made to take the whole load in case of a spring breaking. 



Bridges' Patent (Jig. 415). This inventor ingeniously proposes to use Spencer's 

 cones in blocks of wood, instead of iron confining rings. A series of them are en- 

 closed in a case formed in the side timbers of the underframe of the railway truck or 

 carriage ; the cup space is formed in the block of wood, as our figure shows, and no 



guide rods are required ; the principle is applied to draw- and bearing-springs. The 

 advantages proposed by this arrangement are, the dispensing with guide rods and the 

 taking the ultimate blow on blocks of wood, which deadens its effect ; they are said to 

 answer very well. 



In 1847, Mr. De Bergue patented some improvements in the application of Fuller's 

 spring to buffer-, bearing-, and drawing-springs for railway uses. 



The applications for common road carriages, patented by Mr. Fuller of Bucklersbury 

 in 1852 and 1855, have been extensively used, both in the form of cylindrical rings 

 acting by compression and also of suspension springs for lighter kinds of vehicles. 



Eespecting these springs, figs. 416, 417, wo have been furnished by the patentee with 

 the following particulars : 



The form generally used for heavy purposes, such as drays, vans, waggons, &c., 

 consists of a series of rings of cylindrical or circular form, working in a perpendicular 

 rod or spindle, on each side the axle, with the usual separating plates or washers ; the 

 depth and diameter of tho rings being regulated by the weight to be sustained and 

 the speed required. 



During the Crimean war, these springs were introduced by Mr. Fuller to the notice 



