Push mechanism

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Push mechanism with pull straps and stamps

Coin and medal minting devices that work on the principle of the screw press are referred to as push mechanisms or balancers . While push mechanisms, along with other technical innovations, largely replaced hammer stamping , they were overtaken by the toggle press even in the 19th century . Further historical names for the push mechanism are screw push mechanism, spindle mechanism, pressure mechanism and throwing.

The upper punch of a pusher is pressed against the coin blank with great pressure from the lower end of a spindle screw . The blank lies on the lower die. The pressure arises when a rotary movement of the spindle is directed downwards into a vertical movement via its thread. The upper end of the spindle screw is formed by a swing axis. There are large oscillating masses at their ends . Depending on the size of the push mechanism, the centrifugal masses were set in motion by 2 to 12 workers. In large devices, straps were attached to the flywheels.

Compared to hammer stamping, stamping with the balancer has the advantage of being able to produce large coins in a single stamping process. There is no need to strike several times with a (possibly very large) hammer. In addition to the risk of injury, the position of the blank and / or upper punch occasionally slipped. As a result, there was a double blow called an embossing error . In addition, the stamping performance increases per unit of time.

Very high forces occur during the embossing, which must be safely diverted into the ground. Shock mills were therefore firmly connected to the foundations of the mints or even had their own foundations .

Contemporary illustrations show that in addition to the mint workers who started the push mechanism, another person was responsible for inserting the blanks and removing the minted coin. This person was sitting in a pit in front of the device for large push mechanisms. Push mechanisms were also used in China (see illustration).

In addition to minting coins or medals , push mechanisms or blancier presses are also used for punching out materials such as paper, leather or sheet metal.

See also

Individual evidence

  1. Lexicon article "Münzwesen", section "Production of coins" in Meyers Großes Konversations-Lexikon, 6th edition 1905–1909, p. 276
  2. ^ Lexicon article "Balancierpresse" in Meyers Großes Konversations-Lexikon, Volume 2, 1905, p. 294