A cooktop unit generally comprises: a glass-ceramic cooktop or a cooktop made of similar material; a holding frame; and, a permanent-elastic connection between the cooktop and the frame.
Assemblies are known in the marketplace having a molded-on sealing profile.
This idea in and of itself is good but experience has shown that significant tolerance problems develop when attempting to realize such sealing profiles. This is the case because a seal can be effected only via the periphery and therefore a pressfit must always be ensured. This, however, is not possible because of the tolerances of the cooktop and frame as well as mounting tolerances.
An inadequate seal between the glass-ceramic cooktop and the frame can affect cleaning in practical use and safety during operation. Food being cooked can overflow and trickle into the gap between the seal and the frame and can disadvantageously affect electrical reliability.
U.S. Pat. No. 4,363,956 discloses a glass-ceramic cooktop unit for direct mounting in a workplate of wood, ceramic or plastic (kitchen countertop). This cooktop unit comprises a cooking area with a cookplate made of glass ceramic and the heating elements as well as a peripherally extending mounting frame supporting the cooktop. The mounting frame can be connected, on the one hand, to a peripheral region of the cookplate and, on the other hand, to the periphery of a workplate cutout. Spring elements and adjusting devices are arranged between the cooking area and the mounting frame in order to bring the cooking plate with the cooking area in smooth approximation to the frame against the action of the spring elements.
U.S. Pat. No. 5,036,831 discloses a frameless glass-ceramic cooktop unit which includes the following: a cooktop with a mounting cutout and a peripheral edge in the mounting cutout which includes a flange directed downwardly; a glass-ceramic plate having a peripheral edge; a uniform support ring having first and second essentially planar surfaces with the second planar surface being arranged vertically; and, a sealing material between the first planar surface of the support ring and the lower side of the glass-ceramic plate. This sealing material joins the glass-ceramic plate to the support ring and the second planar surface of the support ring is held against the downwardly extending flange.
The configurations suggested in U.S. Pat. Nos. 4,363,956 and 5,036,831 have been difficult to realize in practice because complex configurations of the mounting frame and adjusting devices and spring elements are expensive to produce and are problematic with respect to installation.