US2928426A - Diaphragm for pump - Google Patents

Description

March 15, 19 w. w. TAYLOR 2,928,426

DIAPHRAGM FOR PUMP Filed June 27. 1952 F ngl s lac INVENTOR. Wei/fer W. 721y/or ATTORNEY United States Patent DIAPHRAGM FOR PUMP Walter W. Taylor, Oakland, Calif., assignor to Malsbary Manufacturing Company, Oakland, Calif., a corporation of California Application June 27, 1952, Serial No. 295,906

4 Claims. (Cl. 137-788) The invention relates to improvements in a diaphragm pump, and its principal object is to provide certain improvements in the diaphragm and in the diaphragm assembly to render the operation of the pump more efficient and to extend the life of the diaphragm.

In diaphragm pumps, as used heretofore, the diaphragm is usually made in the form of a heavy disc constructed of alternate layers of rubber and fabric and having parallel end faces throughout the extent thereof.

The rim of the diaphragm is clamped between fixed rings forming part of the pump housing, and the free portion of the diaphragm is reciprocated by means of a drive plate bearing on one side of the diaphragm and clamped upon the latter by means of a central bolt. The head of the bolt bears upon a washer disposed on the other side of the diaphragm and the driving plate is substantially larger than the washer and extends circumferentially to within close proximity of the anchoring rings.

As the drive plate is reciprocated, by any suitable source of power, and transmits the reciprocations to the diaphragm for pumping action, the main water on the diaphragm takes place along the rim thereof, that is, just inside the anchoring rings. This is due to the fact that the diaphragm, being very heavy and reinforced by the fabric, and of uniform thickness, flexes very little in its main portion, in response to the advance of the drive plate, the main part of the flexing being done along the rim just inside the anchoring rings.

The rim section thus acts in the nature of a well-defined hinge, takes substantially all the bending stresses and, as a consequence, is subject to'heavy wear, whereby the life of the diaphragm is seriously shortened.

As a matter of fact, when a diaphragm of this character is removed for discarding, there is a clearly defined ring just inside the anchoring rings where the material is completely worn out, while the remainder of the diaphragm is still in good condition.

In order to ameliorate this condition it has been proposed, heretofore, to form the driving plate with a convex driving face, to cause the driving face to engage the diaphragm over progressively spreading areas, and to spread the bending stresses over a wider area. But, in view of the construction of the diaphragm hereinabove described, this is only a partial solution of the problem, since the breaking down of the diaphragm material still occurs along the rim.

In the present invention, it is proposed to remedy the situation by providing a diaphragm of novel construction which allows the bending stresses to be distributed over a wide area and eliminates the definite hinge efiect hereinabove referred to.

Further objects and advantages of my invention will be disclosed as the specification continues, and the new and novel features of my diaphragm pump will be fully defined in the claims forming part of this application. The preferred form of my invention is illustrated in the accompanying drawing, in which:

Figure 1 shows a fragmentary axial section through a 2,928,426 Patented Mar. 15, 1960- i ce 2 diaphragm pump disclosing my diaphragm and its mounting means, and

Figure 2, a plan view of my diaphragm.

While I have shown only the preferred form of my invention, it should be understood that variouschanges or modifications may be made within the scope of the claims attached hereto, without departing from the spirit of the invention.

Referring to the drawing in detail, my diaphragm 1 is preferably made of all rubber to increase the flexibility thereof. It is made in the form of a disc having a central bolt hole 2 with a metallic reinforcing ring 3 therein, and is circumferentially confined by a second reinforcing ring 4. The disc is, in its original state, somewhat thicker than the width of the rings to allow of the clamping action hereinafter referred to.

One .side 5 of the disc, which may be referred to as the driving face, is perfectly flat, While the other side 6 has a flat rim section 7, a flat hub section Sand an annular concave groove'9 between the two sections.

While I do not wish to confine myself to any exact dimensions, I might say, that in the diaphragm actually used and recently tested by me, the rim section, the grooved or intermediate section and thehub section are about equal in width along a radial line, as shown in the drawing, and that the groove extends into the disc material to a depth approximately equal to one-third of the thickness of the disc. The, latter may have a diameter of approximately five and one-half inches, and a thickness of approximately one-half inch.

The rim section is formed with an annular series of bolt holes 10.

My diaphragm may be mounted in a pump substantially as shown in Figure l. The pump may be of any suitable construction, and is here shown as comprising a housing 11 having two ring members 12 and 13 clamped upon the rim of the diaphragm by means of a series of bolts 14 passing through the bolt holes 10 in the diaphragm.

The housing is constructed to form a pump chamber 15 on one side of the diaphragm, with suitable intake and discharge valves 16 and 17 for the chamber, the latter facing the grooved side of the disc.

A drive plate 18 is mounted centrally upon the fiat side of the diaphragm and is secured to the latter by means of a bolt 19 extending through the ring 3 in the hole 2. The head of the bolt bears on a washer or confining ring 20 interposed between the head and the flat hub section 8 of the disc, and the end of the bolt is threaded into a nut 21, which latter has a ring 22 mounted thereon operable by an eccentric, not shown, to cause the drive plate to reciprocate.

The drive plate 18 has a driving face which may be substantially fiat in its inner portion commensurate with the size of the washer, but which is convex in its outer portion, as at 23, beyond the circumference of the washer. The diameter of the drive plate is slightly less than the inner diameter of the anchoring rings 12 and 13.

My construction brings the concaved portion of the diaphragm disc substantially opposite the convex portion of the drive plate.

In operation, as the drive plate 18 advances, it progressively contacts the disc in widening circles, urging first the central section and then the grooved or concaved section of thedisc outwardly. In the meantime, the disc, growing progressively thinner, as the contact area widens, offers less and less resistance to bending stresses and flexes rather freely throughout the contact area.

This flexing through a wide area more uniformly distributes the bending stresses in the disc material and does away with the concentration of the bending stress along a narrow rim section, particularly in view of the fact tli'aftoward'thes'aid section; the disc material grows thicker again in the present construction.

I have found, by severe tests, that in my construction,

the tendency of the disc to break at the rim portion adjacent' the'anchoring plates, is substantiallyeliminated, and that the life of the disc is greatly extended.

I claim: V

1. A pre-formed diaphragm for a diaphragm pump having a drive plate with a driving face flat in its central portion and convex in, its outer portion, the diaphragm being" adapted for securing upon, thedrive plate and having a flat face adjacent the drive plate and having a concavegroove in itso'ppo'site'face disposed opposite theconve'x portion of the drive plate when the diaphragm is secured upon the latter.

7 21' A pie-formed diaphragm for a diaphragm pump ha'vin'g a drive plate with a'driving face fia t in its central portio'n and convex in its outer portion, the diaphragm being adapted for' securing upon the drive plate and having a flat face-adjacent the driveplate and having a concave groove in its opposite face disposed opposite the convex portion of the drive plate when the diaphragm is secured upon the latter, and the groove being sub stantially commensurate ,with the convex portion.

3'. A pre-formed diaphragm for a diaphragm pump havingta drive plate with a driving face flat in its central portion and convex in its outer portion, the diaphragm beingadapted for securing upon the drive plate and having a flat face adjacent the driveplate and having a concavegroove in its opposite face disposed opposite the convex portion of the drive plate when the diaphragm is se'c'ured upon thelatter, and the diaphragm having a rim portion extending beyond the groove and adapted for securing between a pair of fixed anchoring members.

4. A pre-formed diaphragm for a diaphragm pump having a drive plate with a driving face flat in its central portion and convex in its outer portion, the diaphragm I being adapted forsecuring upon the drive .plate and having a flat faceadjacent' the drive plate and having a concavegro'ove in its opposite face disposed opposite the convers -portion of the drive plate when the diaphragm is secured upon the latter, the groovebeingsubstantially commensurate with the convex portion, and the diaphragm having a rim portion extending beyond the groove and adapted for securing between a pair of fixed anchoring members.

References Cited in the file of this patent UNITED STATES PATENTS- i r i

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