Final Design
Window Removal and Reinstallation Assembly
From Left to Right: Front View, Isometric View, Back View, Side View
Window Rotation Mechanism
Close-up of ratchet and pawl locking mechanism
Steel Jack Connector
Left: Bulldog Square Jack, w/ Footplate (BD195351/etrailer)
Support Structure:
Aluminum supports were chosen to construct the final support structure. Having two aluminum supports eliminated the risk of side-to-side tipping of the assembly during lifting. The vertical supports also balanced the moment caused by the loaded window, which resulted in the jack being the only component that underwent linear compressive forces. The horizontal mainstays ensured that the suction cups remained parallel and equidistant during use.
Left:Suction Cup, 8", Aluminum Handle, Visual Alarm (Wp-N4950/POWR-GRIP)
Lifting Element:
A crank-operated square trailer jack was chosen for the lifting element. Crank-operated trailer jacks are mechanically simple and inexpensive both in unit purchases and maintenance. The external steel construction was durable, long-lasting, and allowed for welding directly onto the external construction. User feedback was very important during the window removal process, so the reliability of the internal gearbox along with its sensitive 8 rotations per 0.02 meters (1 inch) of slider displacement was favorable. The side-mounted crank provided sufficient leverage for one-handed operation, which reduced physical strain on the operator. The vertical lifting capacity of the jack was 1361 kg (3000 lbs), which exceeded the amount required for the final design. The internal gearbox of square jacks provided better side-lift
capacity compared to tubular or round square jacks. Because the primary load sustained by the jack produced a moment about the internal gearbox, selecting a square jack proved to be the best selection to accommodate the load
From Left to Right: Magliner Aluminum Platform Truck (PTK2448S1-Q/Lowes), 8"x2" Ecoforma Swivel Caster (675 LBS. Cap) with Top Lock Brake (4.08.169.479.BRK7), 8"x2" Ecoforma Swivel Caster (675 LBS. Cap) with Total Lock Brake (4.08.169.479.BRK4)
Moving Device:
An aluminum platform truck with two swiveling casters and two rigid casters was chosen for the moving device. Aluminum is lightweight, strong, durable, and has superior corrosion resistance compared to other alloys of steel. Because aluminum supports were used in the final design, having an aluminum truck allowed for the possibility of welding if it was preferable over bolting. The truck was rated for 1270 kg (2800 lbs), which was far greater than any of the loads encountered in our application. The original casters were later replaced with two top locking and two total locking swiveling casters. The new casters were made of thermoplastic rubber, which provided good slip resistance, shock absorption, and weatherability. These properties allowed for a smooth ride and easy cart maneuverability.
Window Attachment Mechanism:
Suction cups were chosen for the window attachment mechanism because they are the primary method for handling windows and large glass panes. Suction cups have a more linear operation and failure mode. Instead of the window falling off completely, suction cups would slowly lose suction and the window would slowly slip. The suction cups selected featured a visual warning indicator, so vacuum loss can be monitored and easily reapplied with a thumb-activated plunger. The suction cups handles are made of an aluminum alloy, which allows for various mounting options and increased durability. Each suction cup is capable of supporting 57 kg (125 lbs), which is more than enough to support the weight of the window. The final design was fitted with two suction cups, which allowed for increased maneuverability and doubled the factor of safety in case one suction cup failed.
Left: 303 Stainless Steel Ratchet, 16 Pitch, 1-1/2" OD (8938K9/McMaster-Carr) and 3/8" Thick Stainless Steel Pawl (6283K32/McMaster-Carr)
Final Performance of Results
The existing method of removing and reinstalling a window took 3 maintenance workers about 15-20 minutes.
Our assembly allowed 2 maintenance workers to remove and reinstall a window in approximately 5-10 minutes.
Originally, the design was meant to allow for 1 maintenance worker to be able to complete the entire process, but having another maintenance worker alongside to act as a spotter made the process easier.
Left: Aluminum Square Tubing, 2"x2"x20' (214STRC61/Coast)
Window Rotation and Locking Mechanism:
A lever bar in conjunction with a ratchet and pawl was chosen for the window rotation and locking mechanism. The suction cup holders were attached to a rod, which could be rotated with an attached lever bar. The integration of the ratchet and pawl allowed the rotation of the rod to be fixed. Because rotation of the window was a crucial step in removing the window from the frame, having an accessible lever bar that could lock allowed the operator to easily complete the desired motion.
APPROXIMATE DURATION FOR COMPLETION: 9 minutes and 10 seconds*
* The actual duration to complete the removal and reinstallation process may vary due to the initial learning curve for assembly operation and cleaning duration