Car jack product dissection

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Dissection Process

Given the construction process of the jack, dissection could not be done in the lab and had to be done in the machine shop (The jack in a vice awaiting dissection). The pins connecting the arms to the top and base were riveted on. To remove them, we used an angle grinder, and ground off one end of the pin allowing the pin to be pushed out. This was first done to the base pins (Matt grinding off rivets on the base pins, Base after rivets ground off ). After this the pins were pushed through allowing the base to be removed. When this was completed, the process was repeated for the pins attaching the arms to the top (Matt grinding rivets off the top pins,Top after rivets ground off). After pushing he top pins out the top could then be removed. After this step the the right arms and the left arm/threaded-arms assembly could be separated. Next the collar securing the threaded rod was removed (Threaded rod with collar). As the collar was pinched onto the rod, removal was difficult. To accomplish this the collar and rod were placed in vice to bend the collar out slightly, a press and later a hammer were used to finish the removal (Collar and rod assembly in a press). With the collar removed the threaded rod could them be removed from the left pin. This last step in the dissection was to remove the right pins and separate the right arms and do the same to the left. The right and left pins had notches that were bend back onto the arms to secure them. To remove the pin the notches were ground off with the angle grinder (Matt removing the notches with an angle grinder). With the notches removed the pins could then be pushed out and the arms separated. After this was completed , we photographed and documented each piece to complete the dissection.

Reference Image

Bill of Materials

Part #Part NameQty.Weight(oz.)FunctionMaterialManufacturing ProcessImages
0001Base114.7Connection point for lower arms, supports jack against groundSteel, powder coatedStamped and bent
0002Lower Arm212.2Lower part of 4-bar linkage that makes up jackSteel, powder coatedStamped and bent
0003Upper Arm212.2Upper part of 4-bar linkage that make up jackSteel, powder coatedStamped and bent
0004Top16.2Connects upper arms, links 4-bar linkage, connection point and support for vehicleSteel, powder coatedStamped and bent
0005Left Pin16.0Tapped with matching thread to hold and allow threaded rot to rotate, also connects lower and upper left armsSteelExtruded, drilled and threaded
0006Right Pin15.7Acts as a top for thrust bearing, connects right lower and upper arms, holds in position and serves as a guide for threaded rodSteelExtruded, and drilled
0007Threaded Rod115.6Acme threaded rod, with eyelet at the end, when rotated pulls sides together providing upward motion and forceSteelExtruded, threaded
0008Collar11Serves as a stop for the threaded rod, keeps it from overturningSteel
0009Thrust Bearing11Allows rod to rotate under force, keeps jack working when threaded rod is under force from the carSteelPurchased
0010Lower Pin21.2Acts as a pivot point, secures lower arms to base, longer than upper pinsSteelExtruded, mushroomed at ends
0011Upper Pin21Acts as a pivot point, secures upper arms to top, shorter than lower pinsSteelExtruded, mushroomed at ends
0012Crank Arm111.7Lever arms used to rotate threaded rodSteelExtruded, bent

Mechanical Function

In a standard use situation the user would hook the end of the crank arm (0012) into the hole in the end of the threaded rod (0007). A force would be applied to the handle such that it rotated the threaded rod (0007) clockwise. This would cause the threaded rod (0007) to feed into the left pin (0005) which has a internal thread cut into it. The force created by this motion will apply a force to the thrust bearing (0009) which will apply a force to the right pin (0006). This will cause the 2 pins to become closer together. Due to the nature of a 4 bar linkage this will cause the Top (0004) and the base (0001) to separate, lifting the vehicle.

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