Crosshead, guiding

Crosshead guides are cast integrally with engine frame. 

The system oil is used for forced lubrication of the various bearings and crosshead guides present in the crankcase. In some engines it is also used for cooling the piston undercrowns. 

Fig. 10 shows a solder wire press of the horizontal type. The main cylinder is connected to the counterplaten by two columns. The plunger, which is sealed by a stuffing box and packing collars, presses on a crosshead guided in its travel on the columns, and is retracted by a pullback... 

The crosshead guides are of cylindrical or flat design and are in most cases provided with adjustable shoes. All of the sliding surfaces and bearings are to be equipped with forced-feed lubrication. 

Crossheads, running in bored guides, have shim-adjusted babbitted shoes at top and bottom and either full-floating or fixed crosshead pins. Suitable for addition of balance weights. 

Die body, crosshead Wire guide and vacuum seal... 

The columns also serve to guide the container crosshead or the return crosshead respectively, in its travel. In some cases - especially if heavy presses were concerned - four-column presses have been built, which afford better stability. An example of this type is shown in Fig. 18. Stability being of minor importance only on account of the slow operation and the central load in cable presses, preference is in general given to two-column designs, because they afford easier access to the tooling. 

The two-column press, as shown in Fig. 27 and 28, takes the same form of a closed frame as the up-acting press, in that the frame is formed by the cylinder-platen, the bottom platen and the two columns, the ends of which are prestressed by nuts and check nuts on the platens. The plunger crosshead is guided in its travel over the columns and is moved up by two lateral return plungers. The return cylinders are inserted in the... 

Fig. 44 illustrates a billet-fed lead cable press. The up-stroking design, as shown in Fig. 18, is the most suitable type, because the ram must be traversed to permit of charging the billet, for which purpose a small hydraulic cylinder with plunger and guide-frame is fixed on the face of the upper platen. With a down-stroking press, this drive unit would have to be mounted on the movable crosshead which would call for connection by hoses or telescopic tubes. 

The press rests on a base frame which is grouted with the foundation. It has a guide m for the plunger crosshead n which prevents a one-sided wearing of the sealing due to the w eight of the piston. 

The container is lifted and lowered - as Avith the press illustrated in Fig. 105 - by means of two rods o and a common crosshead p. The crosshead is driven by plungers q with their links r and four lateral tie-rods s. In order to prevent a tilting of the crosshead in case of non-uniform plunger powers and due to the long distance between crosshead and cylinder, the crosshead is laterally connected to a through shaft u by levers t, thus providing a reliable guide. 

Fig. 160. Oil-hydraulic 1,200-ton extrusion press for light alloys in three-column design with crosshead being guided on the two top columns (By Hydropress, New York)...

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