Common expedients for these purposes are--jointed folding rods, as a
carpenter’s rule; the telescope tube; net work; diagonally crossed and
jointed bars; lattice work; springs (see Section 80); lazy tongs (No.
623).
=616. Telescopic ram hydraulic lift.= (See also No. 1217.) Consisting of
two or more rams sliding within each other.
=617. Parallel bar expanding grille,= or gate.
=618. Parallel bar expanding grille,= with lazy tongs motion, each
alternate bar has slotted holes as shown.
=619. Modification of 618.= The number of horizontal bars can be
multiplied indefinitely.
=620. Venetian blind;= this method is used also for movable doors or
partitions, sliding horizontally.
=621. Venetian blind,= but without revolving motion to the laths or
slats.
=622. Perforated bar and hooked rod suspender.=
=623. Lazy tongs expanding connecting rod.=
=624. Four-guide expanding link device,= for varying motion.
=625. Thorburn’s tube expander,= operated by a central cone and ring of
conical rollers.
=626. Gasometer.=
=627. Timms’ expanding boring tool.= Operated by a central cone and
three or more diagonal feathers, sliding in dovetail grooves in the
central cone.
Expanding Mandrel, No. 507.
Expanding Chucks, Nos. 489, 491, & 506.
[Illustration: 609.-627.]
=628. Expanding basket,= with chain corner suspenders.
=629. Expanding socket,= with sliding ring grip.
=630. Expanding grating,= formed of bent steel laths on edge.
=631. Bridge or flap= between cars, having buffers.
=632. Expanding core barrel,= in three parts, expanded by a wedge.
=633. Expanding mandril or chuck.= See also Section 28.
Expansion Joint, Nos. 1076, 1077.
Expanding Pipes, No. 1079.