Chapter CXVII: Section 36: Expanding and Contracting Devices

(_See also p. 84._)

=2142. Expanding gate.= Formed of vertical, round, or simple bars, fitted with sliding ferrules having centre pins passing through diagonal bars, these centres being evenly spaced.

=2143. Expanding mandrel;= has three parallel feathers, expanded by a central bolt having two equal cones.

=2144. Expanding socket,= formed of spring wire.

=2145. Expanding legs= for telescope or camera tripod.

=2146. Expanding tripod,= formed to close up into a cylindrical group.

=2147. Expanding table= of three or more slides.

=2148. Expanding tripod.= The legs are hinged to a triangular prism, and form a cylindrical group when closed.

=2149. Expanding reamer.= The body is split up in three parts as far as the end of the bolt.

=2150. Addy’s expanding collar= consists of two rings with the adjacent faces spiral, so that by revolving them they separate to the extent of the pitch. The collar therefore expands longitudinally, not diametrically.

=2151. Expanding split reamer= or mandrel with taper screw.

=2152. Expanding riddle or screen,= to vary the spaces between the bars.

=2153. Expanding collars= or sleeves, screwed one upon another.

=2154. Expanding collet,= split in three or more parts.

=2155. Expanding pipe grip= or collar with bevel gear and right and left-hand screws to operate the three segments together.

=2156. Expanding pipe stopper= with rubber ring. See Section 29.

=Bellows and rubber bags= are used as expanding devices for gases, &c.

=Rubber balloons= are expanded by air blown in under pressure.

=2157. Expanding pulley or wheel.=

=Expanding plug.= See No. 2358.

=2158. Expanding lever.=

=The mercury bulb tube= is an expanding device actuated by
temperature.

(_See also_ Cushioning; Chucks, Section 28.)