US930781A - Air-pump. - Google Patents

Description

E. J. McGUTGI-IEN.

AIB PUMP.

APPLICATION FILED APR. 1o, 1909.

Patented Aug. 10, 1909.

EDWARD JAY MCCUTCHEN, OF MEXICO, MEXICO.

Ain-PUMP.

Specification of-Letters Patent.

Patented Aug. 10, 1909.

, Application filed April 10, 1909. Serial No. 489,091.

To all whom it may concern.'

Be it known that I, EDWARD JAY Mo- CUTCHEN, of Mexico city, Mexico, have invented certain new and useful Improvementsin Air-Pumps; and I hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, `which form part of this specification.

This invention has particular reference to the air pumps employed on locomotives for compressing air for brakingpurposes. These pumpsv commonly comprise an air or pump cylinder, a steam or :motor` cylinder in axial alinement with the pump cylinder, and a steam chest on top of the steam cylinder; the pistons in the air andV steam cylinders are rigidly connected by a common iston rod; and the steam-valve is actuated y a valve rod extending' into the steam cylinder, and engaging a bore in the main piston rod; said rod being engaged by the piston on its ascent, and caused ,to shift the valve; the valve rod then telescoping into a bore in the piston-rod; and on the descent of the pistons a lug or button on the inner end of rod is engaged by a stop or reversing plate on the piston, whereby the rod is caused to reverse the steam valve,- the arrangement being such that the valve is quickly actuated'at the proper times by the movement of the main istons.

When the valve-rod brea s, as sometimes happens, it is necessary among other things,

i in order to repair the pump as heretofore constructed, to remove the pump from the" engine, then remove upper steam cylinder head, then force the piston up as far as it will go and remove reversing turn pump upside down and let roken portion of rod fall out the upper part of the rod can be removed by unscrewing acap-nut above the valve. '.Ihese operations require tackle, tools and time, and such repairs cannot be made by an engineery when on the road Without a great loss of time.

It is the object of the present invention to so improve the construction of such pumps that a broken valve rod can be removed and replaced Without taking the pump down, and in such a quick and simple manner that the engineer can readily make the necessary repairs while on the road in very short time and with little trouble. I accomplish this desirable end by the simple means which I late thenV vwill now explain, having reference to thc aecompan ying drawings which illustrate a well known form of air-pump, embodying my invention.

`In said drawings-Figure 1 is a sectional elevation of an air-pump of the Vl/vestinghouse type, embodying my improvements. Fig. 2 is an enlarged. detail sectional view of a portion of the lower head of cylinder airpiston, piston-rod and threaded plug separated.

In the drawings, A designates the air cylinder; B the steam cylinder; and C the steam chest of an ordinary air-pump for locomotives; a is the air piston; l) the steam piston and c the reversing valve. The pistons a, t, are rigidly connected by a piston rod D which passes through suitable stuffing boxes on the. adjacent ends of the cylinders. The cylinder A has the usual air inlet and exhaust ports and connections; and the cylinder B has the usual steam inlet and exhaust ports controlled by the main steam valve c. The valve c is operated by a valve rod E which extends into the steam cylinder, and enters a bore d in the piston-rod D, so that the piston can reciprocate in the steam cylinder without affecting the valve rod E, except near the extremes of the strokes of the piston t. The valve rod E has a button or head c on its lower end, which is retained in the bore d of thei piston rod by means of the usual slotted reversing 'plate F attached to the piston t, as shown; and near the valve c the valve rod E is enlarged in diameter, forming a shoulder e. As the piston t reaches the upper end of its stroke plate F strikes shoulder e and raises the valve-rod, thereby shifting thevalve c, and causing the opening of the exhaust port below the piston b, and the steam inlet above the piston g consequently the piston l) will be caused to descend. As the piston reaches the end of its downward stroke, plate F catches the button e on the valve rod and draws the latter down, causing it to shift valve c so as to cause the opening of the exhaust above piston b, and admit steam below the piston. Access can be had to the steam valve c by means of a cap-nut or head K in the top of the steam-valve chest, as shown.

The parts thus far described are well known in construction and in operation; the bore d in the piston rod has heretofore been made only sufliciently deep to allow'the upico ward movement of the pistons; and if the rod E is broken, the troublesome and extensive operations above noted are requisite in order to replace it. ln order to avoid such trouble, expense and delays in replacing a broken valve-rod, I make the following improvements in the construction of the pump. The bore d is made continuous throughout the length of piston rod D; its lower end is threaded internally, and is closed by a removable screw plug G which is preferably tapered to insure a steam and air-tight joint. Access can be readily had to this plug G without removing the fastening and locking nuts l usually employed to secure the pistonrod D to piston B. The lower head H of the cylinder A is customarily pocket-ed or depressed at 7L to accommodate the nuts l, and here i use the opening directly in line with the piston-rod D, and of about the diameter of said piston-rod, and close this opening 'preferably by a threaded plug J, so that the normal operations of the pump will not be aifected, no steam can leak past plug G into the air cylinder; nor air leali through the piston-rod into the steam cylinder. By reason of these simple changes a great saving of time and labor is eileeted in ease it becomes necessary to replace a broken rod,-for then instead of taking down the pump-as above stated-the engineer' simply removes plug J, and through its opening has access to plug G, which he can easily remove, whereupon the lower portion of the broken valve rod drops out; then the plugs G and J are replaced. Then the cap K is removed, and the upper part of broken rod removed. Then a new rod E inserted, the lower end of such rod being readily entered into the bore d of the piston-rod D by reason of the usual lateral enlargements or slots f, d', in the reversing plate F and upper end of rod D,-tlien cap K is replaced and the pump is in working order once more.

Having thus described my invention what l claim as new and desire to secure by Letters Patent is:

l. in an air pump, the combination of a pump cylinder', a motor cylinder, and a valve chest in axial alinement; pistons in said cylinders, a hollow piston rod connecting said pistons, a plug in the end of the piston-rod in the pump cylinder; a valve in the valvechest, a valve rod connected therewith and extending into the hollow piston-red, and a plug in the pump cylinder head opposite the plugged end of the piston-rod, substantially as described.

2. in combination, an air cylinder and a steam cylinder in axial alinement, pistons in said cylinders, a piston rod connecting` said pistons, and having a bore extending throughout its length, removable :means for closing` the end of this here within the air cylinder, an opening in the head of the air cylinder adjacent the end of the piston-rod, means for closing said opening, a valve casing on the upper end of the steam cylinder in axial alinement with the pistons, a valve in said casing, a removable cap for closing the end of the valve chamler, and a valve rod connected with said valve and extending through the steam cylinder and engaging the bore of the piston-rod and means on the steam piston adapted to engage and operate the valve.

3. In an air pump the comlination of an air cylinder and a steam cylinder in axial alinement, pistons in said cylinder, a pistonrod connecting said pistons and bored throughout its length, a removable plug closing the end of this here in the air cylinder, an opening in the head of the air cylinder opposite the plugged end of the piston-rod, a plug elo-singa said opening, a valve casing on the upper end of the steam cylinder in axial alinement with the pistons, a valve in said casing, and a valve rod connected with said valve and extending through the steam cylinder and engaging the laire of the pistonrod and having a button on its lower end and a shoulder adj arent the valve, and a retainer plate on the steam-piston adapted to engage the button and shoulder to operate the valve.

In testimony that l claim the foregoing as my own, l al'lix my signature in piesence of t`wo witnesses.

EDV/'ARD JAY MCCUTCHEN. litnesses:

G. A. GUERRA, NIeANnno Aneos.

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