DESIGN AND FABRICATION OF TOGGLE JACK REPORT DOWNLOAD
Toggle jacks are simple mechanisms used to drive large loads short distances. The power screw design of a common Toggle jack reduces the amount of force required by the user to drive the mechanism. Most Toggle jacks are similar in design, consisting of four main members driven by a power screw. In this report, a unique design of a Toggle jack is proposed which is very easy to manufacture. Each member, including the power screw sleeves, is made of the common c-shape. This eliminates the need for machined power screw sleeves, which connect the four members and the power screw together. The manufacturability of the proposed Toggle jack lowers the cost of production.
The most basic Toggle jack design is truly engineering at its finest. With the power to magnify input forces, Toggle jacks allow us to raise vast loads using only a fraction of the force ordinarily needed. Our goal in this project is to design an efficient Toggle jack capable of raising a 10000N load. As a screw-driven mechanical system, the jack will be manually operated and have at least 7 inches under load. The design will be transportable and storable, have a removable crank handle, and operate with a factor of safety of n = 5 using standard mechanical design methods for all components. The design itself has gone through multiple stages of development. We have taken several possible failure modes into account and are confident that our design is efficient and safe.
The Toggle jack design, shown in Figure 1, consists of four main lifting members, eight connection members, a power screw. Members 1 to 8 are all primarily bar shapes with ideal pin connections. Members 10 and 12 both have additional details to account for the contact surfaces. The power screw is double threaded with a collar at the member 12 connection. All members are EN8(C40) steel.
Components used in the fabrication of Toggle Jack:-
a) Power Screw
c) Top plate
d) Base plate
A power screw is a drive used in machinery to convert a rotary motion into a linear motion for power transmission. It produces uniform motion and the design of the power screw may be such that. Either the screw or the nut is held at rest and the other member rotates as it moves axially. A typical example of this is a screw clamp. Either the screw or the nut rotates but does not move axially. A typical example for this is a press. Other applications of power screws are jack screws, lead screws of a lathe, screws for vices, presses etc. Power screw normally uses square threads but ACME or Buttress threads may also be used. Power screws should be designed for smooth and noiseless transmission of power with an ability to carry heavy loads with high efficiency.
Our proposed design is similar to common Toggle designs in some aspects, but also advantageous in others. Similar to others, our proposed design can safely raise a load of 10000N to the required heights with relative ease on the user. Unique to our design, however, is the manufacturability of our design, which is much simpler. Since only Bar-shapes are utilized, bulk material can be more efficiently purchased and used. Also, less machining is required since there are no complex sleeves for the power screw. Only simple attachments which can be welded on are proposed. Therefore, when compared to similar Toggle jack designs that perform equally as well, our proposed design is recommended for its manufacturability and lower cost with high efficiency.