Slide Hammer
Slide Hammer Puller
Sometimes you need a hammer that goes in reverse.
Mechanic pulling a dent with a slide hammer
When you want to pound something out rather than in, what you need is a slide hammer. A slide hammer attaches, via thread, hook, screw, claw or suction to any object needing to be pulled instead of pushed and transmits manually an impact force without having to strike the object itself. The name hammer is a bit misleading since it is not used for striking exactly, but rather violently yanking. In orthopedics, we use such a device (called a slap hammer in that setting) to remove embedded prosthesis, nails, or other metallic foreign bodies, thereby sparing the bone in which it resides any direct force.
Human teeth as a demonstration of asperites
Asperities are the uneven pits and valleys inherent in any solid material and contribute considerably, if not wholly, to the static friction between two surfaces. These asperities not only manifest small areas of contact and consequently pressure, but also settle into one another like the interlockings of our teeth. In order to violate this static friction, great force must be applied and the slide hammer is just the thing to do it.
Force is equal to mass multiplied by acceleration. The shaft of this tool allows a weighted slide to achieve acceleration and impact the far end, producing a meaningful pulling force to the object to which it is attached. In addition to orthopedics, they are also used extensively in the auto body world to remove dents and even rumored to be used by thieves toextract ignition assemblies en bloc. On the farm, it’s the tool that shows up to save the day when all else seems hopeless; for removing rusted rotors, say.
Knowledge Sources
https://outdoorchief.com/what-is-the-best-dent-puller-suction-cup-slide-hammer-tools-reviewed/
https://en.wikipedia.org/wiki/Slide_hammer
https://www.daviddarling.info/encyclopedia/S/AE_slide_hammer.html 89. https://www.engineeringtoolbox.com/impact-force-d_1780.html
https://www.geeksforgeeks.org/static-and-kinetic-friction/
Image Sources
https://commons.wikimedia.org/wiki/File:2008-08-11_Mechanic_straightening_fender.jpg
https://commons.wikimedia.org/wiki/File:Teeth_by_David_Shankbone.jpg
