[Jam Handy Technical Photography Sample, Reel 23, 1940s]

that Engineers have designed with great care to make sure of economical results but the principle is still the same the carburetor has but one purpose and that is to mix a little drop of gasoline with a great big bubble of free air in a one-cylinder engine made for laboratory experiments parts and many types of moving surfaces in the automobile engine consequently the engines in our cars today use all three methods of lubrication a slug is placed in the cup-shaped Dy of a power press then a mechanically operated punch strikes the slug a single downward blow with tr tremendous Force causing the metal in the slug to squirt up around the punch when the punch is withdrawn the aluminum tube remains in the D and is knocked out since the punch is a little smaller than the dye the space between the two determines the thickness of the side walls of the tube and likewise the base of the plunger and floor the dye determine the Contour of the end of the tube another type of Extrusion impact Extrusion starts with the blanking of circular slugs from sheet or plate in all refrigerator we could use one of several different types of pumps or compressors for example PA of oil so that moving Parts can Splash into it for lubrication we can provide a supply of oil on a higher level so that it will trickle down through a system of tubing onto the moving Parts the force of gravity furnishes the power to carry a steady flow of lubricant where it is needed if we want an extra amount of lubrication we can force a stream under pressure directly onto the sliding surfaces by controlling the pressure we can control the lubrication for different speeds there are here instead of a generator we have a water pump these glass pipes take the place of wires connected to a water wheel motor when we spin the pump around we set up a movement in the water water which represents the flow of current in the generator the current flows from the generating pump to the motor and back again and the more water we pump the faster the water wheel motor will spin let's add a glass tank to see how our storage battery works now we can store up power and use it to run the water wheel even when the pump is stopped of course in the automobile it isn't quite as easy as all that but this simplified system shows how the battery stores the electrical current and releases it as it is needed it has to Supply Power for the selfstarter and furnish a hot spark for the spark plugs electric lights add to the load and in order to supply the changing needs the generator must be carefully controlled we don't want to put too much energy into the battery overcharge it and we don't want to put too little energy in or we won't have enough to run extra equipment buying raw materials making more widgets a number one widgets that any customer would be glad to have and while widgets are being bought and sold at one end of the factory raw materials are being sold and bought at the other end so with everything humming along smoothly and everyone working for somebody else money seems to travel round and round in this widget business push in the opposite direction by simply moving the valve to apply the vacuum to the other side of the chamber notice how the smoke shows the air moving in and out as the vacuum changes sides and notice that almost no effort at all is required to move the valve the air does all the pushing the plunger follows the slightest movement of the Val wheels are mounted on separate axles and supported by a frame so that they can revolve freely at different speeds let's fasten a spoke on the inner end of each axle so that by turning the spokes we can turn each wheel separately with a bar or cross piece we can turn both wheels in the same direction at the same rate of speed let's get something to hold this bar in place so that it will press against the spokes notice that this support is not locked to the axle it turns freely now we can spin the wheels by rotating the support this is fine as long as both wheels are able to turn at the same speed but let's see what happens when we go around the corner with this arrangement we cannot drive one wheel faster than the other and if we stop one wheel the other wheel won't budge let's put this bar on a pivot so that it can swing in either direction now the bar can still turn both wheels at the same speed and because it pivots it lets one wheel turn even when the other is stopped but if turned too far the bar will swing around until it won't drive the spokes that turn either wheel we need another crossbar and more spokes to carry on the job when we stop one wheel the crossbars will continue to push the spokes of the free wheeel around as long as both wheels are free to turn the bars do not swing on their pivot and the wheels move at the same speed now we have the working principles of a differential to adapt the model for use in an automobile we will have to make a few changes in order to reduce the jerky action caused by wide spaces between the spokes we will put in more spokes further filling in the spaces between the spokes gives steadier more continuous action and changing the shape gives firm Constant Contact now we can make the gears thicker and stronger and we have differential gears the edges are cut so that they will fit together more smoothly and silently and another gear is added to share the work of driving the axles the principle is the same in order to turn the support and drive the wheels we can fasten a large gear here connected by a smaller gear to a source of power