• Crane Control Equipments

Rotary Geared Limit Switches

Rotary gear type Crane Control make limit switches are used on control/power circuit of reversing drives so as to limit their rotation/movement within a predetermined position. The function of the limit switch is to stop the mechanism of drive at the extreme clockwise/anticlockwise positions. These rotary limit switches are particularly suited for use on reversing drives such as electric hoists, winches, overhead cranes, traversers, etc. The contacts of these limit switches are rated for 40 Amps at 500 V AC. The limit switches can be provided with 2 NC contacts or (2 NO + 2 NC) contacts as per the requirement. The geared type rotary limit switch basically consists of heavy duty worm gear drive with a ratio of 48:1 or 60:1. The rotary limit switch is housed in IP-41 as well as IP54 enclosures. In case of IP-41 enclosure. the housing is made from suitably reinforced sheet steel whereas in case of IP-54, the cover is of cast aluminium. The base and cover also have machined surface to protect the limit switch against dust. The camshaft which extends from behind the gear into the sheet steel housing accommodates the cams. Two or 4 cams are used depending upon whether the rotary limit switch is of 2 contacts or 4 contacts operation.