Automatic center punch

Automatic center punch

An automatic center punch is a hand tool used to produce a dimple in a workpiece (for example, a piece of metal). It performs the same function as an ordinary center punch but without the need for a hammer. When pressed against the workpiece, it stores energy in a spring, eventually releasing it as an impulse that drives the punch, producing the dimple.

Operation

Within the body of the punch, there are three principal moving parts arranged in line:

* The punch rod
* The intermediate rod
* The hammer mass

The hammer mass is spring-loaded from the back of the punch by a large spring. (The spring's compression can be adjusted by loosening or tightening the end cap at the back-most portion of the punch.) There's a hole drilled a short distance into the front center portion of the hammer mass.

The intermediate rod provides the automation. It's designed so that its resting position is skewed and it bears on the hammer mass slightly off-center, on that part of the front of the hammer mass where the hole isn't. As the punch is pressed against the workpiece, pressing the punch rod inwards, the intermediate rod bears on the hammer mass and pushes the hammer mass back against its spring, storing energy in the hammer spring.

At a certain point, a spring and ramp mechanism associated with the intermediate rod straightens out the intermediate rod ("unskews" it). Now centered, the end of the intermediate rod falls into the central hole in the hammer mass and the hammer mass, driven by its spring and no longer held back by the intermediate rod, starts accelerating towards the front end of the punch. But the hole in the hammer mass is only so deep so eventually the moving hammer mass bottoms out against the tail end of the intermediate rod and the impulse of the hammer mass is transmitted through the intermediate rod, through the punch rod, and into the workpiece.

Use in advertising

In the late 1960s, an automatic center punch was prominently featured in the advertisements for "Xerex", a U.S. brand of antifreeze. The can of Xerex antifreeze was punctured several times with an automatic center punch and the antifreeze proceeded to spray out of the can. But the anti-leak agents in the antifreeze then plugged the holes in the can and the spray of antifreeze stopped.


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Punch (tool) — For punches used in punch presses, see Punching. A punch is a hard metal rod with a shaped tip at one end and a blunt butt end at the other, which is usually struck by a hammer. Punches are used to drive objects, such as nails, or to form an… …   Wikipedia

  • Punch (metalworking) — A punch is a hard metal rod with a shaped tip at one end and a blunt butt end at the other that is usually struck by a hammer. A variety of punches are used in engineering, but often the purpose is to form an impression of the tip on a workpiece …   Wikipedia

  • Automatic Message Accounting — (AMA) provides detail billing for telephone calls. When Direct Distance Dialing (DDD) was introduced in the USA, message registers no longer sufficed for dialed telephone calls. The need to record the time and phone number of each long distance… …   Wikipedia

  • Punch press — A punch press is a type of machine press used to cut holes in material. It can be small and manually operated and hold one simple die set, or be very large, CNC operated, with a multi station turret and hold a much larger and complex die set.… …   Wikipedia

  • Automatic Digital Network — The Automatic Digital Network (AUTODIN) is a legacy data communicationsservice in the United States Department of Defense. AUTODIN originally consisted of numerous AUTODIN Switching Centers (ASCs) located in the United States and in countries… …   Wikipedia

  • Key punch — A key punch is a device for entering data into punched cards by precisely punching holes at locations designated by the keys struck by the operator. Early keypunches were manual devices. Later keypunches were mechanized, often resembled a small… …   Wikipedia

  • Marking out — For other uses, see Marking out (disambiguation). Marking out or layout is the process of transferring a design or pattern to a workpiece, as the first step in the manufacturing process. It is performed in many industries or hobbies although in… …   Wikipedia

  • MythBusters (2007 season) — Country of origin Australia United States No. of episodes 25 (includes 4 specials) Broadcast Original channel Discovery Channel …   Wikipedia

  • Drill bit — For the fictional character, see Drill Bit (Transformers). For the cancelled skyscraper nicknamed Drill bit, see Chicago Spire. For the types used in drilling wells, see Well drilling. From top to bottom: Spade, lip and spur (brad point), masonry …   Wikipedia

  • Glossary of firefighting — Note: This list does not include firefighting equipment, i.e., tools and apparatus used by firefighters. Please refer to Glossary of firefighting equipment for such terms. : Note: This list is incomplete. You can help Wikipedia by… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”