Photoelectric switch unit

Claim 1

In combination, a shutter assembly for operating a photoelectric switch unit comprising means defining a pair of relatively superposed upper and lower mounting members which are spaced apart in the vertical direction and equipped with a plurality of apertures including a central aperture in the relatively lower member and a plurality of mounting apertures in the relatively upper member which are arranged in angularly spaced offset relationship about the central aperture in the relatively lower member, and a plurality of shutter members interposed in the space between the mounting members, about the central aperture in the lower member, the bodies of which are individually vertically reciprocably guided in the mounting apertures and yieldably upwardly biased into stopped positions abutting the underside of the upper member, for pushbutton operation against the bias thereon from above the upper mounting member, and which moreover, are equipped with vertically oriented shutter blades that occupy a common horizontal plane in the stopped positions of the shutter members, and extend in angular relationship to one another, relatively laterally inwardly from the bodies of the shutter memberS, opposite the central aperture in the lower member; and a photoelectric switch unit which is detachably associated with the shutter assembly, comprising a base which is positioned relatively below the lower mounting member and has a light source fixedly mounted at a raised level thereon, and a plurality of photoelectric switches also fixedly mounted thereon, the photoelectric elements of which are individually surrounded by an equal number of open-sided casings which are upstanding on the base, in angularly spaced relationship to one another about the light source, with the side openings thereof in a common horizontal plane coincident with the light source and the elements, and which together with the light source, are removably inserted upright through the central aperture in the lower mounting member, and disposed in the space between the mounting members, at a level and orientation in which the planes of the shutter blades and the side openings of the casings coincide with one another, and the blades are interposed in the spaces between the casings, and in the stopped positions of the shutter members, register with the openings of the casings to deenergize the switches.