GB1358264A - Bobbins for electro-magnetic relays - Google Patents

Abstract

1358264 Injection moulded relay bobbin RYFORD Ltd 12 Aug 1971 [23 Sept 1970] 45216/70 Heading B5A [Also in Divisions H1 and B8] An end flange of an electro-magnetic relay bobbin and which is injection moulded from glass-filled nylon, includes a plurality of sockets 20 extending from the outer face of the flange partially through the thickness thereof for the accommodation of tag terminals, with each socket 20 being adjacent, or communicating with, a bore 19 extending through the flange wall for the passage of a wire soldered to the tag terminal. The tag terminal (Fig. 5, not printed) is of planar configuration and is barbed along each edge to ensure retention at a push fit within a socket 20. Each bore 19 and adjacent socket 20 is formed in a boss 14, 16, 17, 18 projecting at each corner from the outer face of the flange, beyond a bounding peripheral wall 13 thereof. When moulded integrally with a tubular bobbin core, an end portion 15 of the core projects from the outer face of the flange to the extent of the wall 13, and is surrounded by a shoulder 42 which functions as a ring gate during moulding, and from which the moulding material is outwardly distributed along projecting rib formations 41 of the flange. The bores 19 each open into a recess 34, 36, 37, 38 in the inner face of the flange, and a guide channel 35 for a wire extends in the inner flange face tangentially from the tubular core into one of the recesses 34. The walls 32 of the recesses define rounded edges around which the wires pass to avoid sharp bending and severing contact of the wires with the sharp edge around the outlets of the bores 19, which are defined during moulding by core pins carried by a moulding die. The bobbin may be moulded with a circular flange at its other end, which is slightly concave on its exterior face and with a tapering inner face to facilitate mould opening. The flanged bobbin is moulded within a three part die comprising one part defining the outer face of the flange having the sockets and bores, and which is separable longitudinally of the tubular core, and a pair of dies which define the remainder of the bobbin and which are separable longitudinally of the channel 35.