Section 48.—LEVERS.

Levers are of three orders (see [Section 53]). The fulcrum or rocking centre may be at either end or at some intermediate point. In practice the fulcra are usually shafts or pins (see [Sections 76] and [77]), and the following are the typical forms in use.

[869], [870], [871], & [872]. Elevation and plans of plain levers, with end bosses for rod attachments.

[873]. Plan of plain lever, with forked end.

[874] & [875]. Bell crank levers, with plain or forked ends.

[876]. T or double cranked lever.

[877]. Forked end, off-set.

[878]. Fish bellied lever of the 2nd order.

[879]. Balance weight lever.

[Larger plate.]

[880]. Hand lever, with round handle.

[881]. Hand lever, with flat handle.

[882]. Another form of round handle sometimes used.

[883]. Crank handle.

[884]. Starting lever, with spring catch.

[885]. Another pattern of ditto.

[886]. Similar lever, with side or crank handles.

[887]. Foot lever.

[888]. Foot treadle frame.

[889]. Wrist plate or T lever.

[890]. Hand lever, adjustable as to length by means of a slot and locking bolt. For this purpose a plain round rod passed through a central socket and fixed at any radial length by a set screw, is often used; or the hand rod may be cranked as [No. 1784].

[891]. Double hand lever.

[892]. Lever, formed of two wrought iron or steel plates and distance pieces.

[893] & [894]. Rocking levers, with sliding swivel joints.

[895]. Forked lever, to span a central bearing.

[896]. Hand lever, simple pattern; wrench or spanner.

[897]. Headed lever, for valve rod and other movements. See [Nos. 149] to [152].