how does the mechanical aspects of a punch press work?
95173
If you have seen how a paper punch works to make three holes (or only one), that is how a sheet metal punch works too.  The sheet metal must have properties that lend themselves to a similar punch operation.  That is much like the "shear" that a pair of scissors can produce but all at once outling the pattern or hole to be produced.  Some machines rely on dynamic force and others are slow using hydraulic pumps and rams to apply the cutting force.  It requires highly skilled tool and die makers to make and sharpen the cutting tools.
109551
Inside a copier there is a special drum. The drum acts a lot like a balloon -- you can charge it with a form of static electricity. \n\nInside the copier there is also a very fine black powder known as toner. The drum, charged with static electricity, can attract the toner particles. \nThere are three things about the drum and the toner that let a copier perform its magic: \nThe drum can be selectively charged, so that only parts of it attract toner. In a copier, you make an "image" -- in static electricity -- on the surface of the drum. Where the original sheet of paper is black, you create static electricity on the drum. Where it is white you do not. What you want is for the white areas of the original sheet of paper to NOT attract toner. The way this selectivity is accomplished in a copier is with light -- this is why it's called a photocopier! \n\nSomehow the toner has to get onto the drum and then onto a sheet of paper. The drum selectively attracts toner. Then the sheet of paper gets charged with static electricity and it pulls the toner off the drum. \n\nThe toner is heat sensitive, so the loose toner particles are attached (fused) to the paper with heat as soon as they come off the drum. \nThe drum, or belt, is made out of photoconductive material. Here are the actual steps involved in making a photocopy: \nThe surface of the drum is charged. \n\nAn intense beam of light moves across the paper that you have placed on the copier's glass surface. Light is reflected from white areas of the paper and strikes the drum below. \n\nWherever a photon of light hits, electrons are emitted from the photoconductive atoms in the drum and neutralize the positive charges above. Dark areas on the original (such as pictures or text) do not reflect light onto the drum, leaving regions of positive charges on the drum's surface. \n\nNegatively charged, dry, black pigment called toner is then spread over the surface of the drum, and the pigment particles adhere to the positive charges that remain. \n\nA positively charged sheet of paper then passes over the surface of the drum, attracting the beads of toner away from it. \n\nThe paper is then heated and pressed to fuse the image formed by the toner to the paper's surface.
900753
The opponent's wrist is grabbed with the hand on the same side, and the opposite arm is put on the back side the opponent's arm, and again grabbing the attacker's wrist and forming a figure-four. By controlling the opponent's body and cranking the arm away from the attacker, pressure is put on the shoulder joint, and depending on the angle, also the elbow joint (in some variations the opponent's arm is brought behind his back, resulting in a finishing position resembling that of the "hammerlock".
18106
This is from personal observation.  [Ballpoint] The body of a pen is hollow and contains a tube filled with ink, tapering to an open point.  That open point is plugged with a metal ball affixed in a position where it cannot get quite out of the barrel or into the supply of ink.  However, it can move slightly, and when pressed against a surface and pushed, the ball rotates, and the face turned to the ink is turned out of the pen and deposits that ink onto the surface, while the empty face rolls in to face the ink supply.
68566
When a force is exerted on an object, pressure is also exerted on the object, but force and pressure are not the same thing. Pressure...what exactly is pressure? Pressure is a force (a push), and depends on two factors: how big is the push, and what is the area that is being pushed. Pressure can be measured as :\n\nP = Force/Area\n\nA force is a push or a pull acting upon an object. Forces result from interactions between two objects. Most interactions involve contact.
663121
Most aerosol cans are steel so they won't explode (they're cheaper too).  If aluminum is required, thicker walls are needed, and they must be stamped out of aluminum sheet.\n\nThe punch press machines are big and expensive, and you need progressive dies to transfer the aluminum from station-to-station, so you will need a toolmaker too.  The formed cans need to have the top attached, crimped, decorated, and filled with product.  The cans need to be tested for bursting, and quality control is needed.  This is a big, big job, indeed, it will require a factory.\n\nCommercial cans initially were produced by Coors Brewing Company from impact-extruded 1xxx-O slugs and, later, from relatively thick 3xxx-O sheet.  The real breakthrough, though, came when Reynolds Aluminum developed draw-and- iron technology for the use of hard (H18 and H19) tempers.  This technology allowed for considerable reduction in metal thickness, and, therefore, more economical, lightweight cans.\n\nW.F. Hosford and J.L. Duncan, “The Aluminum Beverage Can,” Scientific American (September 1994), pp. 48–53\n\nThe aerosol can, of course, must be thicker than a beverage can.\n\nA standard punch press can form the cans, but sophisticated progressive die tooling is needed.  Unless you're going to become a major manufacturer of aluminum aerosol cans, would it be less expensive to purchase the cans, already stamped?
351987
Belt filter presses need at least 1% solids content to operate efficiently, but this depends on the sludge and waste water characteristics.  If the particles are small they will have a tendency to clog the belt and the flow rate will be drastically reduced and the belt will require more cleaning.  Typical feed concentrations are 2 to 5% solids for biological treatment sludges.  Belt filter presses rely on gravity and pressure from rollers and belt tension to force the water from the sludge.  Typical dewatered sludge is 20 to 35% solids\n\nPlate filter presses can be effective on low solids waste streams but are more of a batch process.  These rely on pump pressure to help dewater the sludge, but can deliver higher solids content that belt type presses.  The plate filter press will need more operator intervention empty and clean the sludge from the press.
214853
Often they use pad printing... they find a mold to hold each product in exactly the same spot... then a thing comes over... presses down and puts the ink on... but there are other methods as well...
683520
It is the machine design. A vacuum is used to form the can that initially forms the bottom and sides. When the top is added it crimps the top by a tool that rolls the metal.
30601
The "How Stuff Works" website has good page on this subject.\nhttp://people.howstuffworks.com/newspaper4.htm\n\n"Beginning around 1970, newspaper production divisions began a historic shift away from the labor-intensive technology of Linotype typesetters and other 'hot type' machines used in relief printing.\n...\nMost daily newspapers have moved to some form of offset printing. This process etches the image of a newspaper page onto thin aluminum plates."\n\nThe Encarta website has a good picture of a modern printing press.\nhttp://encarta.msn.com/media_461543535_761564853_-1_1/Printing_Newspapers.html
878201
Generally, the force is applied at the point of "input force" - that point is determined by what class of lever you're using.\n\nFor example, if you're using scissors (First class lever), the fulcrum is at the pivot between the two handles and blades, the input force is at the handle, and the output force is on the blade.\n\nIf you're using, say, a wheelbarrow (2nd class lever), the fulcrum is at the wheel, the input is on the handle (end), and the output force is in the middle - in the bucket.\n\nFor a baseball bat (third class levers), the input force is in the middle (your hands), fulcrum at one end (you), and the output force is at the other end (the end of the bat).
299278
http://www.exportersindia.com/india/manufacturers/q/quick-action-fixture-for-press-tools.htm\n\nhttp://www.kellysearch.com/in-product-71475.html\n\nHope thats helpful.
951860
It's difficult to explain without diagrams.\n\nFirst you have an air supply at about 20 psi that flows through a restrictor and a small nozzle the same size as the restrictor. There is a flapper, a small piece of metal that covers the nozzle and controls the backpressure between the nozzle and the restrictor. The pressure between the restrictor and the nozzle is controlled between 20 and 100KPa (3 to 15psi) by the position of the flapper. The position of the flapper is controlled by the input current (usuall y 4 to 20mA of 1 to 5V). Thus the input signal varies the pressure out. I havent seen any links but I will look
567649
do you mean surface?  as in surface area?  \n\nassuming you do, if you push on something with the same force, but the pushing is being done with objects of different surface area, the object with less area will create greater preasure, and the object with more surface area will create less preasure.  it's like if you're wearing high heals versus flip flops and you step on someone's hand with all your weight.  which will hurt more?  it's the same amount of weight each time, but one has a much smaller surface that's pressing on the hand--->way more pain
890476
It is often a problem in gyms with machines using pulleys.  If the pulley is a single one, then whatever weight is on the stack is what you're lifting, but many machines have some sort of mechanical advantage, so there might be 100kg on the stack, but you aren't actually exerting 100kg force (kgf).  On Earth a kilogram mass exerts a kilogram force downward, so we can ignore the "force" term.\n\nI keep a little retractable tape in my gym bag so every time I come across a new machine, I do the following (it's easier if you have someone to help you):\n\nMeasure the distance the weights actually rise during the full range of the exercise, and multiply that by the total weight.  That gives you total work in kg-metres.  So you might have 50kg on stack, and your shoulder press raises it 0.45m. So that's 22.5kg-m of work.\n\nNow measure the distance your hands move through the exercise (usually significantly further than than the weights). This might be 0.65m.  Divide your work (22.5kg-m) by this distance (0.65m) to get the force at your hands, in this case 34.6kg. So if you did a free weight shoulder press, around 35kg would give you the same effort as 50kg on the machine.\n\nA special case is the 45 degree sliding leg press machine.  Your legs may push the slide about 0.5m, but the weights have only risen vertically by 0.5 x sine 45 deg, or 71% of the slide distance i..e. 0.35m.  So pushing the 200kg on the rack is only 141 kg force at your feet, and your total work is 71kg-m.  That doesn't count the platform weight of course.\n\nI always record work as well as weight, as a heavy weight is not necessarily heavy work.  As an extreme example, anyone can lift a wheel of a 1-ton truck off the ground with one hand - using a jack!
710153
Usually psi (pounds per square inch).\n\nAloha
982675
First, learn to absorb the force of a punch, when his punches make contact breath out and shift your body to coil back on the side he hit you on this will reduce the force of his blows and allow you to take more hits.\n\nThen when you punch keep both feet firm on the ground, bring your punching force not from your fist but from your hips or even better the bottom of your feet. This will add power to your punches making your blow hurt him more\n\nRemember: it takes twice as much strength to hit and miss than to hit and make contact. Keep moving, strike when you know you will make contact, this will give you control of the fight.