A trolley jack is a hydraulic two-piston vehicle lifting device that converts downward force applied to the handle, or first piston point, into upward force at the second piston point. According to Thomasnet.com, the jack also amplifies the initial force. Trolley jacks work reliably on flat surfaces such as asphalt and concrete. However, they are unsafe to use on angled surfaces, grass, gravel and sand.Know More
Trolley jacks are filled with oil, which lubricates their moving parts and does not oxidize metal. The oil also creates an extremely efficient hydraulic system that intensifies almost all of the initial downward force and transmits it to the second piston.
Trolley jacks have several advantages over other automotive jacks. They offer comparable maximum extension but fold down into a flat unit for convenient storage in small spaces. Small elevator systems often employ trolley jacks as the primary lifting mechanism.
Trolley jacks are not meant to be carried in vehicles for emergency use. Robert Jones, a columnist for HowItWorksDaily, writes that scissor jacks are more effective for this purpose because they are vehicle-specific and safe to use on gravel, dirt roads and on gently sloped surfaces. Advanced models are electric. These plug into vehicle cigarette lighters and perform all lifting functions without manual assistance. As with conventional jacks, safe operation of electric scissor jacks requires proper placement beneath the vehicle chassis.Learn More
The Jack La Lanne Power Juicer is a great tool, but it must be maintained properly to get the best results. Use the steps below to remove the blade to clean it and verify that it is working properly.Full Answer >
Refrigerator thermostats work by measuring the amount of warm air present within the unit and cycling it through a cooling mechanism to achieve the desired temperature. The warmth threshold can be set through a dial within the refrigerator.Full Answer >
A microwave bombards food with waves of energy, causing water molecules in food to vibrate and heat up. These waves, which only affect polar molecules, can pass transparently through most cooking vessels. The resulting heat or steam cooks the food much faster than traditional cooking. This is because the heat comes from everywhere in the food at once instead of working its way in from a heating element.Full Answer >
There are many different types of float switches, some of which are mercury switches that activate by allowing the liquid metal to complete the circuit, and others that are simple floats connected to a microswitch that activates the device. They are common in sump pumps, dishwashers and other appliances.Full Answer >