Fly presses

It is the object of this section to indicate the possibilities of the fly press. The great diflioulty encountered with tliis maehme is in tlie making of the tools, and a typical common example, a tin box, will be taken and dealt with pr<5grcssivt Iy, It must not l>e thought, however, that the fly press is strictly Hmitwl to the l>res.sing of articles... 

Fly Press Described.— The machine to which these dies an fitted is know n as a pre.ss. Tlu Se are otawatod by either power or hand and are tj pified as pow er... 

Holes and apertures can be cut using a simple hand-operated punch or a punch and die fitted in a fly press. 

Where a number of components require the same size hole in the same position, it may be economical to manufacture a punch and die for the operation. The operation is carried out on a fly press, Fig. 4.5, with the punch, which is the size and shape of the hole required, fitted in the moving part of the press. The die, which contains a hole the same shape as the punch, but slightly larger to give clearance, is clamped to the table directly in line with the punch. When the handle of the fly press is rotated, the punch descends and a sheet of metal inserted between the punch and die will have a piece removed the same shape as the punch. Fig. 4.6. 

With the use of simple tools, the fly press can also be used for bending small components. Fig. 4.7. The top tool is fixed to the moving part and the bottom tool, correctly positioned under the top tool, is fixed to the table of the press. Metal bent in this way will spring back slightly, and to allow for this the angle of the tool is made less than 90°. In the case of mild steel, an angle of 88° is sufficient for the component to spring back to 90°. 

Blanking, piercing and bending of light work where the required force is small and the production rate Is low may be carried out on a fly press. 

State the major advantage in using a hand operated fly press. 

Punching presses, ranging from simple hand-operated fly presses to large power presses. 

Crystalline membranes were made from the powders of Ag2S and Agl mixed in the ratio 1 1 by weight and pressed in the fly press at 150 bars for 3 h. Silver metal layer was attached to one side of the membrane and then the contact wire was soldered to this layer. Both types of membranes were moimted separately into special bodies for flow-injection setup. At least three sensors of each type were tested. The polymeric sensors were conditioned in 0.01 M solution of cyanide at least for 1 day before measurements. 

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