Tray Lift Assist Device
User Manual and Operating Instructions
Table of Contents
Section 1: Device Overview
1.1: Overview
1.2: Subassemblies
1.3: Main Features
1.4: Safety Devices
Section 2: User Instructions
2.1: Setup Instruction
2.2: Work Instructions
Section 3: Maintenance Information
3.1: Disassembly Instructions
3.2: Preventative Maintenance
3.3: Recommended Spare Parts
3.4: Full Parts List
Section 1: Overview
The Tray Assist Lift Device described in this document was created to improve the ergonomics of lifting tasks encountered in the Wegmans Bake Shop. This section will give a brief overview of the device, its systems, and their functions.
1.1
Fig. 1 – Device without plastic covering
The device, shown in Fig. 1 with its plastic covering removed, is designed to assist with stacking tasks. The basic purpose of this device is to automatically keep the working surface at ergonomically optimal height while trays are being loaded and stacked. This is to eliminate the need for the operator to bend over, thus reducing back strain and preventing injuries and costly lost time incidents. The device uses compressed air and springs as power sources and requires minimal operator interaction to operate.
1.2: Subassemblies
1.2.1: Main Frame
Fig. 2 – Main Frame
Fig. 2 shows the frame assembly of the device. The frame is made from welded square steel tubing for strength and minimal maintenance.
1.2.2: Fork Assembly
Fig. 3 – Fork Assembly
Fig. 3 shows the fork assembly. This assembly is what ultimately will support the work surface. It is constructed of welded steel.
1.2.3: Air Piston and Springs
Fig. 4 – Air Piston and Spring Assembly
Fig. 4 shows the air piston and spring assembly. These are mounted to the top of the frame and connect to the fork assembly. They control the rate of descent and ascension of the work surface.
1.2.4: Wheel and Track Assembly
Fig. 5 – Wheel and track assembly
Fig. 5 shows the wheel and track system that secures the cart to the frame and allows for smooth vertical movement.
1.2.5: Air System (Not Shown)
The air system is what controls the movement of the work surface. It allows the work surface to be manually lowered if needed as well as automatically locking the work surface in the lowest level once the forks reach a certain level.
1.3: Main Features
1.4: Safety Features
- Hard stop at 2 inches to avoid crushing anything caught underneath forks
- Plastic siding to keep appendages away from moving parts and pinch points
- Canvas covering over slots where forks move up and down to minimize access to pinch points
- Steel spring housing to minimize danger in a spring failure
- Button to lower forks all the way to ground easily
- Yellow fork tips to increase visibility
- Yellow legs to increase visibility
- Lips on ends of forks to keep dollies from sliding off
Section 2: User Instructions
2.1: Setup
1. Place the device in a position that allows easy access to the forks and the operation buttons. Also ensure that the stacks of trays slide off the forks in the desired direction.
2. Attach an airline to the air hookup at the rear of the machine.
3. Ensure that there are no air leaks coming from the device by listening for escaping air.
4. Once it has been confirmed that there are no air leaks the device is ready to use.
2.2: Operation
Step 1: With forks in raised position, load a dolly onto the forks with the long direction of the dolly running parallel to the forks, as shown in Fig. 2.1.
Fig. 2.1: Proper dolly orientation
Step 2: Place a tray on top of the dolly, ensuring that the try is lock in position and will not slide around. This is shown in Fig. 2.2
Fig. 2.2: Tray loaded onto dolly
Step 3: Load the tray with the product. As product is loaded, the tray will automatically lower.
Step 4: Once tray is full, place another empty tray on top of the first tray and load product into this tray as before.
Step 5: Repeat loading of trays and product until twelve trays are loaded on the stack. Once the trays have been stacked about 5 high the forks will automatically lower and lock in the lowest position.
Step 6: Once all the trays are loaded, roll the stack of trays off of the fork towards destination.
Step 7: When and only when, the stack of trays is clear of the forks press the uppermost (Fig 2.3) button to raise the forks. Keep this button pressed until the forks are 8 inches off of the ground.
Fig 2.3: Proper height of forks when button can be released
Step 8: Once the forks have cleared 8 inches they will continue to rise as long as the lowering button (Fig 2.4) is not pressed.
Step 9: Repeat Steps 1-8 until job is completed.
NOTE: If the forks need to be lowered before the fifth tray has been added, press the lower button shown in Fig. 2.4. This will lower the forks to the ground and allow partially completed stacks to be unloaded easily.
Section 3: Maintenance Information
3.1: Disassembly Instructions
Step 1: Shut off air and purge system by pressing the up and down buttons for 10 seconds. This should effectively remove all pressure from the system.
Step 2: Appropriately lock out the system.
Step 3: Remove theplastic siding by unscrewing the screws holding it on.
Step 4: Disconnect springs by extending springs and disconnecting carabineers from eyebolts on fork assembly.
Step 5: Remove cotter pins holding the upper ends of the springs.
Step 6: Remove pin connecting air piston to fork assembly.
Step 7: Unbolt and remove spring towers.
Step 8: Disconnect airline from air piston.
Step 9: Unbolt and remove air piston from top of frame.
Step 10: Unbolt and remove wheels from side of fork assembly.
Step 11: Remove fork assembly from frame.
Step 12: Unbolt and remove tracks from inside sides of frame.
Step 13: Unhook airlines from limit switch.
Step 14: Unbolt and remove limit switch.
Step 15: Remove air lines from buttons.
Step 16: Unbolt and remove buttons.
Step 17: Disconnect airlines from regulator, valve, and filter assembly.
Step 18: Remove regulator, valve, and filter assembly.
3.2: Preventative Maintenance
Daily:
Inspect plastic siding for cracks and wear. Replace any broken pieces immediately.
Inspect canvas for tears. Replace damaged pieces immediately.
Weekly:
Check air system for leaks and damaged tubing. Replace and damaged parts immediately.
Check operation of buttons and limit switch. Adjust if necessary.
Monthly:
Lubricate wheels and tracks with a light-weight lubricant.
Check bolts securing tracks. Tighten if necessary.
Check springs for obvious wear. Replace if necessary.
Check air piston for wear and leaks. Replace if necessary.
Yearly:
Replace air filter.
Check frame and fork assembly for wear and damage. Repair if necessary.
Check wheels and tracks for wear. Replace if necessary.
Reapply yellow markings if necessary.
3.3: Recommended Spare Parts
Quantity / Part Name / Details/ Part Number / Source1 / Aluminum Tie Rod Air Cylinder / 6491K208 / McMaster
1 / Extension Spring / 8433K47 / McMaster
2 / Wheels, size:2 / WZ-22 / Reid Supply
2 / Bearing, size: 2 / WZ-96 / Reid Supply
1 / Track, size:2, 48" / WZ-37 / Reid Supply
10 Ft / 1/8" Hose / 5644K11 / McMaster
1 / HDPE, 48x48" / 8619K447 / McMaster
3.4: Full Parts List
Quantity / Type / Part Name / Details/ Part Number / Source1 / Sub Assembly / Aluminum Tie Rod Air Cylinder / 6491K208 / McMaster
2 / Part / Extension Spring / 8433K47 / McMaster
2 / Part / Steel Eyebolt with shoulder / 3016T16 / McMaster
4 / Part / Wheels, size:2 / WZ-22 / Reid Supply
4 / Part / Bearing, size: 2 / WZ-96 / Reid Supply
4 / Part / Track, size:2, 48" / WZ-37 / Reid Supply
1 / Sub Assembly / Mechanically-Operated Air Control Valves / 6464K13 / McMaster
1 / Part / Rod Clevis W/Pin for Air cylinder Rod / 6491K63 / McMaster
1 / Part / Air Piston Flange Bars / 6491K172 / McMaster
1 / Part / Pivot Bracket / 6491k179 / McMaster
2 / Air / Muffler / 4402K51 / McMaster
4 / Air / 1/8 Hex Nipple M to M / 5485K21 / McMaster
1 / Air / 1/8" Hose, 50ft / 5644K11 / McMaster
11 / Air / 1/8 NPT to 1/8 Hose / 5779K102 / McMaster
1 / Air / 1/8 m f f T / 50785K219 / McMaster
1 / Air / Needle Valve f f 1/8 / 4995K11 / McMaster
1 / Air / 1/8 f f f T / 5779K31 / McMaster
1 / Air / Hose To Wall Manifold 1/4 f / 6534K56 / McMaster
2 / Air / 1/4 to 1/8 Hose / 5779K108 / McMaster
1 / Air / Pop Up Relief (note 50psi) ¼ / 48435K71 / McMaster
1 / Air / Double Acting Regulator f to f / 4964K22 / McMaster
1 / Air / Filter Air / 4274K94 / McMaster
1 / Air / 1/8 f f f T / 9151K41 / McMaster
2 / Air / Momentary Switch f f f / 6464K18 / McMaster
1 / Air / PTFE Tape, 50ft / 4591K11 / McMaster
4 / Siding / HDPE, 48x48" / 8619K447 / McMaster