SU987533A1 - Multi-limit electromeasuring instrument switching device - Google Patents

Description

(S) COMMUTATION. DEVICE OF THE MULTIPLE ELECTRIC MEASUREMENT DEVICE

one

The invention relates to electrical measuring equipment, mainly for high-volume models of multi-range portable electrical measuring instruments.

Switching devices are known which contain a range switching knob with a flat rod and a leaf spring clamped on it with fixing elements included in the corresponding recesses of the instrument lid, a metal plate with measuring indexes (measuring ranges), fixed on the front side of the instrument cover.

However, due to the inclination of the flat spring, the fixing elements may fall out: there is an incomplete coincidence of the handle pointer with the range marks on the plate, and the signs on the east plate are iran.

The closest to the invention according to the technical essence is a switching device of a multi-limiting electrical measuring device, comprising a cover, a handle with a pointer mounted on an axis with the possibility of rotation, a spring and fixing elements f 2.

In the known device, the fixation elements have been eliminated, but nonetheless, there is an incomplete coincidence of the handle pointer with the range marks on the plate and the abrasion of the indicators on the plate.

The purpose of the invention is to increase technology and durability.

Claims (2)

To achieve this goal, the switching device of the multi-limiting electrical measuring instrument, containing a cover, a handle with a pointer, can be rotated on an axis, a spring and fixing elements, is provided with a ring with recesses under the fixing elements and with ledges under the range marks, while the ring is set to cover. In Figures 1 and 2 of the illustration, a proposed device in two projections; in fig. 3 - the same, in a perspective view; in fig. - view A in FIG. The device contains a cover 1, a handle 2, a pointer 3 handles, an axis k in the form of a flat rod, a spring 5 t plate, a fixation element 6, a ball, a ring 7 with depressions 8 under the fixing elements and ledges 9 under the range marks. When casting the lid 1, the ring 7 is inserted into the mold and, after pouring, is firmly held in the lid. The ring 7 is made, for example, of a phenolic plastic, which is higher in strength than polystyrene, of which the cover 1 is usually made. The need for durable plastic is due to the fact that the ring must have a high resistance to wear, as it is moved from the element under load. 6 fixings. The use of thermoplastic plastics with lids 1, having lower strength, is dictated by the presence of a wide range of colors in these plastics, mainly, of light colors and their low cost. The color of the ring 7 and the cover 1 should be the same. The switching device is as follows. When the knob 2 is rotated, the axis rotates the spring. The elements 6 fixation fix the position of the axis, and 9 3 through it - the position of the switches. The readout is based on range marks. The invention makes it possible to eliminate the mismatch of pointers, which is very important in the large-scale production of devices, in which it is difficult to achieve or it is not economically viable to achieve high precision in the manufacture of parts. In addition, the invention eliminates the need to use a front plate, which reduces the cost of the instrument, and the use of non-erasable range marks increases the durability and reliability of the instruments. The invention The switching device of a multi-limiting electrical measuring device, comprising a lid, a handle with a pointer- mounted on an axis can be rotated, a spring and a fixing element, characterized in that it is equipped with a ring with recesses underneath to improve processability and durability. fixation elements and ledges under the markings of the ranges, while the ring is installed in the lid. Sources of information taken into account in the examination of T. Austrian patent number 212-427, cl. 21e 28, i960. 2. USSR author's certificate No. 646259, cl. G 01 R 1/00, 1977.