34 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Fkb. 



ON REVERSING ENGINES. 



Fig. 1. — Section oi Smoke-box. 



Fig. 2.— Transverse View of Smoke-box. 



Sir — As we have seen in your pages a plan of reversing engines, 

 signed G. Coe, civil engineer, which is in principle similar to ours, of 

 which we have been constructing a small sectional model for a locomo- 

 tive engine, we take the liberty of sending you a small sketch of it, with 

 the request, if you think it worth your attention, to give a place in 

 your Journal. Figs. 1 and 2, show only those parts of a locomotive 

 engine, which are wanted for the explanation of our new improve- 

 ment. 



A is the steam-pipe which carries the steam into a cylinder B, fixed 

 in the smoke-box. In the cylinder B, of about 8 inches inside diame- 

 ter, move 2 pistons C and D, connected by a pipe E, which can be cast 

 between the pistons, as the distance between C and D must be always 

 the same. The piston rod is connected with the pistons by means of 

 a boss fixed to D, by 3 stays, and is guided in the stuffing boxes G 

 and H. On the top of the cylinder B, is the exhausting pipe F, on 

 its sides are short pipes K K' and L L', which have a section of Sin. by 

 liin., where they enter the cylinder, and a round section on the other 

 end. 



The steam cylinders M M', have instead of valve boxes, cylinders 

 N and N', with pistons 1 and 2, similar to those in the cylinder B, 

 and those cylinders N and N' are connected with B by means of the 

 pipes K K' and L L. The pistons 1 and 2 will act exactly like a 

 common valve in respect to shutting and opening the steam pas- 

 sages 3 and 4 of the steam cylinders M M', as they are moved by 

 a common eccentric, (keyed to the crank shaft) by means of the levers 

 R S and Q F. 



As we have given now all the explanation of the different parts shown 

 in the sketch, we will next explain how we start, reverse, and stop the 

 engine, without disengaging the spindles of the pistons 1 and 2, from 

 their eccentric rings. 



Suppose the engine is to start in the direction shown by the arrow 

 the stand of the pistons C D in the cylinder B, would be as the sketch 

 shows it. The steam will pass through the pipe E, go through the 

 pipes L L, down to the cylinders N N', round the pipe 5 through the 

 passage 3, into the steam cylinder, and drive the piston in the direc- 

 tion of the arrow ; the steam on the other side of the piston will pass 

 through the passage to the pipe 5, up through K K', and enter the 

 cylinder B, from where it can freely exhaust by the pipe F. If it is 

 wanted to stop the engine, the rod O is moved, by means of a lever or 

 a handle with a screw above the fire-box, towards B, till the pistons 

 cover the pipes L L', in that case the pipes K and K' will still allow 

 the steam to pass round the pipe E, into the pipe F, and as there is 

 not any more steam entering the steam cylinders, the engine will stop. 

 It is clearly to be seen that the engineer has it quite in his power to 

 change the areas of the pipes L L', by moving the pistons backwards 

 or forwards, without altering the areas of the pipes K K'. 



To show now the reversing of the engine, the rod O is moved in the 

 direction towards B, so that the piston D' opens the communication 

 between the pipes L L' and the exhausting pipe F; and by this the 

 pipes K K' will come in communication with the steam pipe A. The 

 steam will pass through K K',the pipe 5, and the passage from 2 into the 

 steam cylinder, and force the piston 6 in the reverse way ; the steam 

 from the other side of the piston passes through the passage 3, round 

 the pipe 5, up through the pipes L L', and out in the exhausting pipe F. 

 After this explanation it will be seen that by moving our apparatus 

 for moving the engine, a regulator is not required. 

 We have now to describe how to get lead. 



There is only one broad eccentric keyed to the crank shaft, with 

 two eccentric rings, each having a circular slot, which is shown in 

 fig. 3. 



