US1967314A

US1967314A - Flexible diaphragm device

Info

Publication number: US1967314A
Application number: US590910A
Authority: US
Inventors: David W Lloyd
Original assignee: Westinghouse Air Brake Co
Current assignee: Westinghouse Air Brake Co
Priority date: 1932-02-04
Filing date: 1932-02-04
Publication date: 1934-07-24
Anticipated expiration: 1951-07-24

Description

D. W. LLOYD July 24, 1934. 1,967,314

FLEXIBLE DIAPHRAGM DEVICE Filed Feb. 4, 1932 Fign iNVENTOR.

DAVID W. LLOYD A TT ORNE Y.

, ture under pressure.

Patented July 24, 1934 1,967,314] FLEXIBLE DIAPHRAGM DEVICE David W. Lloyd, Clayton, Ma, assignor to. The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application February 4, 1932, Serial No. 590,910

2 Claims.

This invention relates to movable abutments for fluid pressure equipment, and more particularly to that type of abutment which comprises a flexible diaphragm and a follower which is adapted to be actuated by thediaphragm.

With the ordinary flexible diaphragm type of movable abutment, it has been found that under usual operating conditions, certain portions of the flexible diaphragm engage the guide surface of the plunger forming an integral part of the follower, and that due to such engagements, the diaphragm is chafed and soon weakened to such an extent that it is liable to buckle or rup- Another objection to the diaphragm engaging the surface of the plunger is that it interferes with the free traverse of the follower.

, An object of the invention is to provide means for preventing the flexible diaphragm of a mov- 1 able abutment, engaging the guide surface of a follower or plunger carried by the diaphragm.

Another object of the invention is to provide a movable abutment structure and aguide therefor, which constitutes a support for the diaphragm and which prevents distortion or collapse thereof when the diaphragm is subjected to fluid pressure.

These and other objects of the invention that will be made apparent throughout the further description thereof are attained by means of the movable abutment structure hereinafter described and illustrated in the accompanying drawing; wherein Fig. l is a sectional View of a device embodying the invention, the movable abutment being shown in the position it occupies when subjected to fluid pressure sufiicient to overcome a retracting spring; and

Fig. 2 is a sectional view of a fragment of the 'device shown in Fig. 1, the movable abutment being shown in the retracted position to which it is moved by a spring.

Referring to the drawing, the movable abuts ment is disclosed as applied to a fluid pressure T device, wherein the movable abutment which may be operatively connected to a valve device (not shown), and which is moved in one direction by fluid pressure against the opposing force of a spring, is moved in the opposite direction by l the spring when the pressure, is relieved.

V The equipment comprises, for example, a casing 3, defining a chamber 4 to which fluid under pressure is adapted to be supplied, and which is closed by a movable abutment comprising a flexible diaphragm 5 having a relatively deep anthe position shown in nular corrugation 6 for permitting relatively long travel of the follower or plunger 7 that is clamped to the central portion of the diaphragm by a v threaded disc or nut 8. The diaphragm is clamped between the end flange 9 of the casing 3 and a cap 11, which is secured to the casing by clamp bolts (not shown) in the usual manner, so as to provide a fluid tight seal between the chamber 4 and the atmosphere.

The follower or plunger '7 is provided with an integral valve operating stem 12, that may be connected to a slide or disc valve or to valve operating linkage (not shown) .as preferred. The follower is also provided with an integral guide portion 13. The cap 11 is provided with a bore 14 in which the plunger 13 is slidably mounted, and the chamber 15 at the upper face of the plunger may be open to the atmosphere through a passage 16.

A spring 17, centered between the cap 11 and 75 the plunger 7 by a lug 18 in the cap, and a recess 19 in the plunger 7, urges the abutment from Fig. 1 toward the position shown in Fig. 2.

In the usual abutment structure of the type described and having a flexible diaphragm with a deep corrugation, there is a tendency of the fluid pressure in the chamber 4 to force a wall 21 of the corrugation into contact with the guide surface 10 as the plunger is being moved into the bore 14, thereby subjecting it to a chafing action. Such action eventually wears the diaphragm and causes rupture thereof and also prevents free movement of the movable abutment, and is, therefore, undesirable.

In the improved structure, the inner face of the cap 11 is provided with an annular groove 22 conforming in contour with the outer surface of the corrugation 6 of the diaphragm as indicated in Fig. 1, and which fully supports the diaphragm and determines its contour when the diaphragm is subjected to sufficient pressure to compress the spring 1'? and permit movement of the plunger 7 to the position shown in Fig. l. Distortion or collapse of the diaphragm is therefore prevented.

The annular groove 22 provides an annular head or rim 23, that is engaged by the wall 21 of the corrugation when the diaphragm is subjected to pressure and occupies the position shown 5 in Fig. 1, and serves to hold the corrugation of the diaphragm out of contact with the plunger. Chafing and consequent destruction of the diaphragm is therefore prevented by the provision of the annular bead or rim 23.

While I have disclosed the invention as applied to a fluid pressure device for operating a valve equipment, it is obvious that the invention is applicable to a variety of movable abutment structures employing diaphragms and that changes may be made in the construction without departing from the spirit of the invention.

Having now described my invention, what I claim. as new and desire to secure by Letters Patent, is:

1. In a fluid pressure device, a casing and a cover therefore, having a guide way and a corrugated flexible diaphragm clamped between the casing and the cover and having a plunger provided with a guide engaging portion movable with respect to the guide Way, the said cover having an annular groove adjacent the guide way for receiving the corrugation and supporting it out of contact with the guide engaging portion of the plunger.

2. In a fluid pressure device, the combination with a casing having a guideway, and a plunger provided with a guide portion and movable into the guideway, of a flexible diaphragm having a relatively deep corrugation and supported at its periphery by the casing and attached at its central portion to said plunger and adapted to be in folded condition when the plunger is in its inner position Within the guideway, the said casing having an annular groove adjacent the guideway for receiving the corrugation when the free portion of the diaphragm is in folded condition for supporting the corrugation out of engagement with the guide portion of the plunger.

DAVID W. LLOYD.