BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
In the drawings, wherein similar reference characters denote similar elements throughout the several views:
FIG. 1 shows a radial cross-section through a laminate membrane according to the invention;
FIG. 1A shows a detail of FIG. 1;
FIG. 2 shows a top view of the laminate membrane shown in FIG. 1;
FIG. 3 shows a bottom view of the laminate membrane shown in FIG. 1;
FIG. 4 shows an alternative embodiment of the invention, in a representation that corresponds to FIG. 1;
FIG. 4A shows an enlarged portion of FIG. 4; and
FIG. 5 shows a detail representation of a further embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a laminate membrane for membrane pumps, having a plate-shaped elastomer body 1 and a product-side contact layer 2 made of PTFE. It is particularly evident from the detail magnification of FIG. 1A that a barrier layer 3 that serves as a permeation barrier is disposed between the contact layer 2 and the elastomer body 1. Furthermore, an intermediate layer 4 is provided between barrier layer 3 and elastomer body 1. Intermediate layer 4, just like the product-side contact layer 2, consists of PTFE, while barrier layer 3 consists of PFA.
As shown in FIG. 1, elastomer body 1 is configured as a circular plate that has a plate edge 5 with a clamping surface, a bottom 6, and a flexible membrane segment 7 that connects the plate edge 5 with bottom 6. In FIG. 1, bottom 6 of elastomer body 1 contains a core 8 that is vulcanized, with a connector device 9 for a piston rod. Elastomer body 1 itself contains a textile reinforcement layer 10 and has a ring-shaped circumferential depression 11 on its elastomer back side, in the transition region between plate edge 5 and flexible membrane segment 7. Looking at FIG. 1 to 3 together, it becomes evident that flexible membrane segment 7 has a plurality of nubs 13 on its top side 12, facing the product, which form elevations in PTFE contact layer 2. Nubs 13 are configured as calottes, i.e., cup-like elevations, having a base area that is preferably circular. Furthermore, flexible membrane segment 7 also has a plurality of nubs 13′, which form elevations on the elastomer back side 14 of elastomer body 1. These nubs 13′, as well, are configured as calottes having a preferably circular base area.
FIG. 4 shows an alternative embodiment of the invention, in which bottom 6 of elastomer body 1 has a central opening 15 for connecting to a piston rod.
According to another alternative embodiment of the invention, shown in FIG. 5, barrier layer 3 that consists of PFA is applied to the side of PTFE contact layer 2 that faces away from the elastomer body 1.
Accordingly, while only a few embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.
Patent Application
20080020178
