Section 17.—CONNECTING RODS AND LINKS.
[295]. Turned and finished link without any adjustments; ends may be solid, or forked as [No. 297].
[296]. Flat link of similar description, with raised bosses for facing and wear.
[297]. Adjustable link, with right and left hand screw coupling. Lock nuts may be added to prevent the coupling working back.
[298]. Strap link, fitted with brasses, gibs and cotters, and distance bar. In this link the wear of brasses is all taken up one way by the gib and cotter; therefore, if great accuracy in the distance apart of centres is necessary, gibs and cutters should be fitted at both sides of one pair of brasses, or [No. 299] adopted.
[299]. Turned link with adjustable end brasses. The forked end should be used where there is the greatest amount of wear.
[300]. Wood connecting- or pump-rod with wrought-iron strap ends, fitted with brasses, gibs, and cotters. Much used on mining pumps.
The shafts or rods are sometimes of cast iron of cross or T section, but are usually of a circular or flat section and swelled in the middle, similar to [No. 299]. See Struts and Ties, [Section 102].
[301]. The most usual form of shifting link for link-reversing gear, generally got up bright all over.
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[302]. Similar link, but having the point of suspension on a side pin, fixed by screws to the link, and raised from it sufficiently to allow the sliding block and pin to pass under it.
[303]. Reversed curve link.
[304]. Solid bar link, sometimes adopted for cheapness and simplicity, the valve rod and eccentric rods having of course forked ends.
[305]. Double bar link. This is also a simple and cheap construction; the bars are plain, the rod ends single, and the block turned large enough to have a recess on each side to fit the links.
[306]. Strap head connecting rod end, with square brasses, double gibs and cotter.
[307]. Strap head connecting rod end, but with rounded end and set screw fastening for cotter.
[308]. Similar to the last, but with screw cotter adjusting device for the brasses.
[309]. Solid end rod. The brasses take out sideways.
[310]. Forked end rod.
[311]. Strap end for heavy rods, having cotter for tightening the strap to the V’s in the rod end. The oil cup is often forged and turned solid on the strap, as shown.
[312]. Rod end with side strap. The brasses take out transversely by taking off the side strap.
[313]. Solid end and double set screw fastening for cotter.
[314] & [315]. Solid ends for small rods. The brasses are usually secured by a set screw.
[316]. Solid end, split with screw bolt tightening device; may be hinged as shown by dotted line.
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[317]. Covered solid end for crank pins, with screw adjustments for brasses.
[318]. Common forked rod end, with cap.
[319]. Hook bolt attachment for gudgeon; sometimes useful where there is thrust only on the gudgeon.
[320]. Double connecting rod, in which the rods form also distance rods and bolts for the heads, which are in halves and fitted with brasses of the ordinary type.
[321]. Marine type of rod end, having solid end, square brasses and cap.
[322]. Marine head, in which the brasses are extended to form the central block in halves, the rod end being of T shape and bolted through the brasses and cap.
There are innumerable varieties of the illustrated types of heads in use, every engineer having his own design.