USRE2954E - den nissok - Google Patents

Description

@uiten l,tetes 'atcut @frn TO ALL WHOM IT MAY OONOERN:

THE GoULD MACH-mn COMPANY, or NEWARK, NEW JERSEY, ASSIGNEES BY MEsNE ASSIGNMENT-s or JOHN-N. DnNNIssoN- or SAME PLAGE.

Letterel Patent No. 46,219, dated .February 7, 1865; reissue No.. 2,954, rlaterl .May 26, 1868.

tlg Sammlerefemh tu in this; Etnias tant ant mating gint uf its samt Be it known that JOHN N. DENNrssoN, of the'eity of Newark, in the county of Essex, and'State oi- New Jersey, made lcertain newand useful Improvementsv in'Relation to Fire-Engines; and we do hereby declare the following to be a full and exact description of thelsame,rreference being had to the drawings accompanying this specification, and which make part of the same. I

The said invention is especially applicable to steam fire-engines.

The nature-of the improvement consists in-regulating or varying the` effective area of the pumpor pumps of tire-engines, soas to obvia'te the difficulties now experienced, contingent upon thenumher of streams used,

The relative areas ofthe steam-cylinders'and the pumps attached to fire-engines, as heretofore constructed, are lunchangeable, and remain the same under all circumstances; but in view of the variable demands upon them when working at fires, some means of varying their relative proportions is a great desideratum,

Water, when forced through one thousand feet vof two andrthree-quarter hose, und through a one and onei eighth nozzle, requires a pressure of two hundred pounds on the water at the pump to give forty-'five pounds l at the nozzle, while a pressure of one hundred pounds on the water at pump, forcedv through four hundred feet of two and three-quarter hose, and' through a one and one-eighth nozzle, will give the same pressure at nozzle, namely, forty-five pounds.

Therefore, a steam-cylinder and pump, proportioned so as to give forty-tive pounds pressure on the water at tho nozzle, when forced through one thousand feet of hose, can work double the area of pump whenforcing water through four hundred feet of hose, and throw two streams of the same size without increasing the speed of the engine, and will give the same pressureat the nozzle as when one stream is forced through Aone thousand feet, namely, forty-five pounds. To adapt the engine'to work to the best advantage under the various conditions above alluded to, thc pump or pumps, under the said DENNISSONS invention, are so made that the eective area.

of their pistons can be changed, so as to deliver a larger or smaller quantity of water with a given motion of the steam-piston.

To enable others skilled in the art to which the invention'a-ppertains tofully understand and use the same, wo will proceed to describe a way of carrying it into. eii`ect. l

In the accompanying drawings--` Figure 1 represents a side elevation, and

Figure 2 avertical longitudinal section of two double-acting pumps, illustrating-the said invention.

The cylinder and pumps are so proportioned that the using of one pump only,`or one half of each pump,- will give the neccssary'supply and-pressurc for fcrcinf a single stream through one thousand feet of hose,"a.nd the use of the whole of both pumps will give an adequate supply and pressure to throw two such streams, when using four hundred feet of hose.A The change is effected by opening or closing the valve between the two pumps, t-hereby'halvingor doubling the working-area of the pumps.

The two pistons,'A A, are attached to the'one piston-rod, B. The water enters by the induction-passage C,

and passes'. out at the valve T. In the partition D, between the pumps, is shown a slidevalvc,"E,'and an open-` ing, S, by means of which water, can pass alternately from the one to the other with.the stroke-of the pistons, without receiving or discharging water, thus entirely neutralizing the action of one half of each double-acting pump, if so required, and increasing or diminishing the quantity of waiterthrown at e. stroke as the various circumstances may require, such as the number of streams thrown or the length of hose used, thus overcoming the dificulties above mentioned by working apart or the whole of the pumps. v i

By opening an air-cock 'placed between the upper and'lower valves, (as at 1),) the pump will be caused to discharge its water, and then take in air, preventing the operation of 'that part of the pump; or. by `placing cock or valve in thc'induction-pipe or passage C, between the pumps, th same resultswill be accomplished, as

it cuts o the supply of one of the p uinps,' although it will not ansn'er the .purpose as well, as itis- 'liable to leak, let in f she air, ande-lso labor under `n vacuum, or, if the whole of one 'pump is cut oil', the pump itself` becomes heated from `the friction of the-piston.

The following is what we claim as new in the invention of the said JOHN N. DENNIsso'N:

1. .A force-pump, which may be adapted to throw a. larger or smal-ler quantity of water at Aeach stroke, by varying the eiective nren. of its piston-surface, by meapsrsuhshantially as herein sei; forth.

2. A force-pump, provided with one or more ports or passges, the opening of which will relieve a part of the p iston-surfaee from labor or pressure on the water, so that the whole powerof the metor cnn be applied to the water delivered from the pump-by the operative part of the piston,V substfinfially ns described:

3. Increasing or diminishing the effective area of the punnp or pumps by means' of e. valve placed in the Vpartition between th'em, so that the quantity of wafer discharged at a. stroke can be increased or diminished at pleasure, withou-t nltering'the speed or stroke, substantially as described..

GOULD MACHINE COMPAN Y; [e 8.1

- ey. FRA-NK H. GOULD, Presman. Witnesses:

'3. J. GoULD, C. HALSEY CANFIELD,

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