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Hospital beds have special features both for the comfort of the patient and for the convenience of health care workers - Leaving Cert Engineering - Question 8 - 2018
Question 8
Hospital beds have special features both for the comfort of the patient and for the convenience of health care workers. Common features include adjustable height for... show full transcript
Worked Solution & Example Answer:Hospital beds have special features both for the comfort of the patient and for the convenience of health care workers - Leaving Cert Engineering - Question 8 - 2018
Step 1
Describe, with the aid of a diagram, how the mechanism shown may raise and lower the height of the bed.
Answer
The hospital bed features a hydraulic lifting mechanism that involves a hydraulic cylinder and a foot pedal pump. When the pedal is pressed, it activates the hydraulic cylinder, which pushes the scissor arms upwards, raising the bed. Conversely, pressing the foot pedal down releases pressure in the hydraulic system, allowing the bed to lower. The diagram should illustrate the hydraulic cylinder and the foot pedal in relation to the scissor lifting mechanism.
Step 2
Explain, with the aid of a diagram, how the side rails may be collapsed to allow a patient ease of access to the bed.
Answer
The side rails of the bed can be collapsed using a parallel linkage mechanism. This mechanism allows vertical links to pivot downward, lowering the side rails to the horizontal position. The diagram should depict the side rails in both their upright position and their collapsed state, clearly showing how the vertical links facilitate the movement.
Step 3
Explain how a stepped cone pulley can change the speed of a machine.
Answer
A stepped cone pulley mechanism allows for different speeds of a machine by utilizing multiple pulley sizes. When the belt is on the smallest driving pulley, it will run on the largest driven pulley, resulting in a slower speed. Conversely, if the belt is on the largest driving pulley, it will connect to the smallest driven pulley, leading to a faster speed. This effectively enables speed variations in the machine's operations.
Step 4
Give two applications for a universal joint.
Answer
Applications for a universal joint include:
- Steering mechanisms in vehicles, enabling the transmission of torque while accommodating the angle between the steering wheel and the wheels.
- Shaft systems connecting machinery, allowing for the transfer of motion even when shafts are not aligned.
Step 5
Outline the operation of a single acting pneumatic cylinder.
Answer
A single-acting pneumatic cylinder uses compressed air to move a piston in one direction. When compressed air is introduced into the cylinder, it moves the piston forward. If no compressed air is applied, the piston returns to its original position due to a spring mechanism. This allows for controlled movement in one direction while relying on the spring for retraction.
Step 6
Describe, with the aid of a diagram, a suitable steering mechanism for the golf cruiser shown.
Answer
A suitable steering mechanism for the golf cruiser involves a rack and pinion system. The steering wheel is connected to a pinion that engages with a linear rack. This arrangement allows the turning of the steering wheel to rotate the pinion, moving the rack left or right and consequently turning the front wheels of the cruiser. The diagram should show the configuration of the steering wheel, pinion, and rack, along with the movement of the wheels.
Step 7
Describe two advantages for having a single rear wheel cruiser over a single front wheel cruiser.
Answer
- Greater stability for the vehicle, as the rear wheel supports the majority of the weight, providing a balanced ride.
- Improved braking effectiveness due to the weight distribution favoring the rear, resulting in better traction during stops.