Double diaphragm pump

[0001] This application claims the benefit of U.S. Provisional Application No. 63/542,333 filed Oct. 4, 2023, which is incorporated herein by reference in its entirety.

[0002] The present invention relates to diaphragm pumps and more particularly to double diaphragms having valve balls at suction and delivery manifolds selectively enabling one of two chambers to fill and exhaust fluid, respectively and alternatingly.

[0003] Double diaphragm pumps have been around for a long time. The applicant owns U.S. Pat. No. 8,469,681 for a double diaphragm pump. Other companies have other designs.

[0004] In the applicant's double diaphragm pumps, there are suction and delivery valve balls that seal on seats depending on which of two fluid chambers are filling with or exhausting fluid. The respective suction valve balls for each fluid chamber selectively seal near the suction when the other fluid chamber is intaking fluid. Delivery valve balls selectively seal on seats near the discharge or outlet as the other fluid chamber discharges. When one fluid chamber is filling, the other is sealed off at the suction with its suction valve ball. When one fluid chamber is discharging fluid, the other fluid chamber's discharge is sealed off with its delivery valve ball. Also, as one fluid chamber fills, the other discharges in an alternating manner.

[0005] In the prior art cross section as can be seen in FIG. 1, a double diaphragm pump 2 has suction valve balls 3,4 proximate to inlet 5 and delivery valve balls 6,7 proximate to outlet 8. As one can see in this cutaway drawing, the valve balls 3,4,6,7 have three axes of motion as they move on and off their respective seats 9,10,11,12 about cavities 13,14,15,16.

[0006] Specifically, suction valve balls 3,4 move upwardly into cavities 13,14 respectively when fluid is passing by the respective suction valve ball 3 or 4. When discharging past delivery valve balls 6,7 the delivery valve balls 6 and 7 respectively move into their respective cavity 15,16 as fluid passes thereby. At their respective fluid chamber is either acquiring fluid as it relates to the intake or suction past suction valve balls 3,4 or discharging past the delivery valve balls 6,7 as appropriate, the respective valve balls 3,4,6,7 move into the respective cavity 13,14,15,16. The valve balls 3,4,6,7 move in all directions 18,19,21 about the cavities 13,14,15,16, whereby additional wear on the valve balls 3,4,6,7 is caused by the movement of the valve balls 3,4,6,7, in all directions within the cavities 13,14,15,16, leading them to make contact with various surfaces & intersecting sharp, thus requiring the valve ball 3, 4, 6 or 7 and its regular seat 9 or 10, 11 or 12 to require replacement over time.

[0007] Additionally, in prior art designs accessing the suction valve balls 3,4 or seats 9,10 at the suction is difficult. A maintenance technician typically must remove the entire pump 2 from its installed location so as to be able to access and remove the lower manifold 17 to be able to inspect and/or replace the suction valve balls 3,4, and/or seats 9,10.

[0008] Improvements over prior art designs are believed to be desirable in the marketplace.

[0009] It is an object of many embodiments of the present invention to provide an improved inspect/repair-in-place capability for a new double diaphragm pump which has an ability to remove the bottom manifold while the pump remains in place.

[0010] It is another object of the present invention in at least some embodiments to provide ball guides within the manifolds which significantly limit valve ball travel during operation primarily along a single axis of motion.

[0011] It is another object of the present invention to provide an improved double diaphragm pump.

[0012] Accordingly, in accordance with a presently preferred embodiment of the present invention, a double diaphragm pump is supported at an elevation above a horizontal surface such as on legs whereby the lower manifold which normally provides a suction to the pump may be removed from the pump while the pump body remains in place so as to access the lower pair of valve balls for inspection and/or replacement along with the lower seals and/or lower manifold. These valve balls normally act on seats near the lower manifold selectively when alternating between filling the two fluid chambers of the pump.

[0013] Another feature of many embodiments of the pump as shown herein, are ball guides which act on the suction valve balls near the intake or suction manifold and/or ball guides which act on the delivery valve balls at or near the discharge manifold or outlet. These ball guides restrict valve ball movement away from sharp edge contact. The ball guides preferably have inner faces which have curvatures which approximate the valve ball curvature so as to prevent harsh contact of the balls with inner walls of the manifold or surfaces adjacent to or within the cavities. For many embodiments, these ball guides essentially limit the movement of the valve balls to substantially linear travel along a single axis on and off the respective seat. By limiting the valve balls degree of motion and providing the rounded surfaces to contact, life of the valve balls is estimated to be greatly increased for at least some embodiments.

[0024] FIG. 2 shows a pump 20 of a presently preferred embodiment of the present invention. Pump 20 has at least a first support 22 if not first and second supports 22,24, preferably in the form of legs or other structure which elevates a bottom manifold 26 a distance or elevation 28 above a horizontal surface 30 such as a plant floor or other structure. By elevating the lower manifold with the suction connection or inlet 32 above the horizontal surface 30, an operator may remove bolts or other connectors to remove the lower or bottom manifold 26 from the pump 20 such as by removing the connectors or bolts which would proceed through bores 34,36,38,40 etc., and then be able to remove the bottom manifold 26 as illustrated from the pump body 50. This capability permits the operator to inspect suction valve balls 42,44 and/or seats 46,48. To the applicant's knowledge, no competitor has such a capability.

[0025] While a removable lower or bottom manifold 26 while the pump body 50 remains in place is certainly an attractive feature for many embodiments not all embodiments need to have such a feature.

[0026] Another feature of the present embodiment can be seen with reference to FIG. 4 when compared to FIG. 1. Namely, the suction valve balls 42,44 and/or the delivery valve balls 52,54 are preferably restrained so as to have essentially a single axis of motion illustrated as axes 55,56,58,60 as opposed to three degrees of motion illustrated in FIG. 1 for each of the various balls 3,4,6,7, suction cavities 13,14,15,16. This feature may be accomplished through the use of guides as will be discussed in further detail below.

[0027] FIG. 6 shows a cross section of the pump 20 shown in FIG. 4. A cross section of manifold 26 shows the first suction valve ball 42 relative to its seat 46. First, second and third guide portions 62,64,66 are shown limiting the travel of the suction valve ball 42 (similar or dissimilar structure 44) so that the suction valve balls 42,44 can only travel substantially linearly, such up and down and may be restrained from side to side motion (or otherwise along other axes). The interior of the guide portions have inner surfaces 68,70,72 which are preferably curved somewhat close to the same radius of curvature of the surfaces of the suction valve balls 42,44 so there are preferably few or no sharp edges that as the suction valve ball 42,44 moves up and down along respective axis 55,56, instead of striking the inner confines of the affected fluid chamber 74,76,78,80 or contacting sharp edges, restricting the motion to linear in the fluid chambers 74,76 and to only contact curved surfaces 68,70,72 of guides which contact the valve ball 42,44,52,54, provides for distributed load on the surfaces of the suction valve balls 42,44 to increase their lifespan and prevent other problems that may have existed in prior art designs.

[0028] FIG. 6 shows a bottom view of the upper manifold 82 with discharge ball 52 on the seat 84. The second ball 54 is not shown but guides 86,88,90 are shown which restrict the ball from traveling in essentially a linear orientation. These guides 86,88,90 are shown having curved surfaces (similar to the curvature of balls 52,54) like the lower guides. FIG. 8 shows the same manifold 82 with the ball removed.

[0029] FIGS. 7 and 8 also show this manifold 82 with various guides 92,94,96 which preferably have curved surfaces to accommodate the diameter slightly larger than the diameter of the ball 52 and preventing the ball 52,54 from contacting rough surfaces as the ball moves on and off the respective seats proximate to guides 84,94 as would be understood by those of ordinary skill in the art. Motion of the balls 52,54 is preferably substantially linearly in the cavities or fluid chambers 78,80.

[0030] FIG. 9 is useful to show a top view of a bottom view of the pump body 50 above the lower manifold showing the guides 100,102 which assist in maintaining the ball 42 in the desired location as it relates to forward and sideways while allowing principally or substantively only reciprocating (linear) movement of the ball 52. There are preferably at least three guides per fluid chamber 74,76,78,80 so that the valve balls 42,44,52,54 preferably do not contact rough surfaces within either the pump body 50 as it relates to the suction valve balls 42,44 and within the upper manifold 82 as it relates to the delivery valve balls 52,54 as fluid leaves the outlet 104 as understood by those of ordinary skill in the art.

[0031] As it relates to the inspect and repair feature of the lower manifold 26, a user can disconnect lower manifold 26 from the pump body 50 and then move it as illustrated in FIG. 2. The seats 46,48 on the lower manifold 26 are easily accessible and the suction valve balls 42,44 may drop out of the pump body 50 for replacement and/or inspection. Reversing the process can then be done to reassemble the pump 20. By having the pump body 50 suspended above the horizontal surface 30 by elevation 28 sufficient clearance is provided while maintaining the pump body 50 connected to the legs and the vertical surface 30 during these procedures.

[0032] Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.