Project 1
Forearm Crutch:
Forearm crutches are utilized by a lot of people who have disabilities or are recovering from an accident. By shifting the weight from the lower to the upper body, they aid in maintaining balance and stability. One or two crutches are used, depending on the severity of the condition.
Strength, comfort, coordination, and comfort are the four main requirements for a set of crutches. Aluminum alloys make up most of a crutch. These alloys are strong and light, and they give the crutch the stability it needs to support the user's weight without bending or deforming the metal.
The plastic cuffs that make up forearm crutches have the ability to bend, allowing the user to put their arm through them while still remaining stable while walking. The crutch handles can be rubber or plastic, depending on the manufacturer or the customer's requirements. Rubber is more comfortable, but plastic is more long-lasting.
On crutches, the shock-absorbing gel is typically contained within a rubber tip. Stainless steel is frequently used in the construction of height adjusters, screws, and bolts.
Materials used in forearm crutch and its properties:
The forearm crutch consists of a frame, grip handle, cuff, tip, and height adjustments. All of these parts are made of different materials that were chosen for their ability to meet the part's specific mechanical requirements.
The frame of the forearm crutch is frequently made of an alloy of aluminum. Because of its low density, aluminum is light and portable, making it easy to move. Besides, it is serious areas of strength for very, the prop to hold an individual's entire load without bowing or twisting. Aluminum is also easy to work with and resistant to corrosion, ensuring a long lifespan. Plastic cuffs hold the forearm crutch in place. It is typically made of a plastic like nylon-6/6. It has strong resistance to abrasion and hydrocarbons to withstand walking's constant rubbing against skin and contact with hydrocarbons. Additionally, it has a lot of strength and rigidity to offer the user a lot of support.
The grip handles of the forearm crutch can be made of rubber or the same plastic as the cuffs. While rubber is more comfortable and better at absorbing shock, plastic is more durable and resistant to wear.
The tip of the forearm crutch is made of rubber. The rubber provides sufficient grip and stability to prevent walking slippage. Additionally, it has superior shock absorption to lessen walking impact.
Clamps and adjustment pins are two examples of many different types of mechanisms for adjusting the height. Stainless steel is used to make the majority of these mechanisms. Due to its low deformation and high strength, this connects the various parts of the main frame in a stable way. Additionally, it resists abrasion, making it durable and suitable for use outdoors.
Manufacturing process:
The production of forearm crutches consists primarily of two steps:
the manufacturing of plastic arm cuffs, hand grips, and rubber tips that can be changed out using hollow aluminum tubes.
While some crutch manufacturers prefer to purchase pre-made hollow tubes in a variety of sizes and shapes, many others prefer to manufacture their own to achieve the precision and quality they require.
Drawing is the cycle by which an exceptionally warmed beginning billet (stock) is attracted through a bite the dust to lessen its breadth and stretch its length constrained to make the aluminum empty cylinder. The process makes the desired tube's surface finish and dimension accuracy better, so the starting billet has to be hollow at first. The material's internal properties are preserved by the initial heating process, which allows it to be soft while still remaining solid. Water quenching is used to rapidly cool the tube following completion of this drawing process.
Depending on the crutch's desired shape, holes are punched through the hollow tube at various points along its length. This is for the final assembly, where all of the parts need to be attached.
Arm cuffs, hand grips, and rubber tips are made using an injection molding process with an IMM (injection moulding machine) or injection press. This machine can be mounted with a variety of mold cavities to accommodate the various desired part shapes.
The first step is to melt the plastic polymer by feeding it into the machine's heating unit. Through an opening known as a sprue, the molten material is then injected into specific mold cavities with high pressure to form the arm cuff, hand grip, or rubber tip. To compensate for the shrinkage that will occur once the material begins to solidify, the cavities are filled and more material is poured into the machine than is necessary to fill the molds. The part is then ejected from the machine after the molds are opened and held together until it is fully shaped and cooled.
This particular type of manufacturing is best suited to the production of rubber and plastic products like arm cuffs and hand grips due to the precision and accuracy with which it shapes parts and the complexity of the shapes it can make.
After all of the components have been finalized and checked for quality, the forearm crutch is assembled as a finished product.
Possible design changes:
We examined a typical metal underarm crutch with top plastic cuffs and handle rubber cushioning. Despite being useful, these crutches have a few shortcomings: The first is that these crutches need a lot of energy, and the second is that overuse of the hands and wrists might result in injury to the user. The aluminium crutches could be replaced with single-piece, curved graphite models.
Functionality, expense, and sustainability will all be considered in the analysis of this design modification below.
Functionality
Curving the crutches
By being curved, the crutches work as shock absorbers and greatly lessen the impact on the user's upper body. As the crutch is straightened, it will also enable the user to maintain energy and move forward. This will save the user a lot of work and make walking longer distances on crutches less uncomfortable and exhausting.
One Piece design
There are fewer parts because the crutch is now made up of just one piece. Because there are fewer pieces that can break, the crutch is easier to construct and will last longer as a result.
Graphite
Graphite can bend without giving way and has a far greater energy retention rate than metal. Because graphite is lighter than aluminium, the user can conserve energy.
Cost
At 1990 USD per tonne, aluminium is somewhat more expensive than graphite, which is priced at 2000 USD per tonne. Despite the fact that aluminium is less expensive than graphite, the benefits of using it in design outweigh the higher cost by a significant margin. The user would prefer spend a little bit more for the extra benefits compared to metal crutches.
Sustainability / Environment
It seems illogical to use graphite instead, which cannot be recycled as easily, since aluminum is a material that can be recycled easily. However, recycling is only one aspect of sustainability.
Graphite is a material that will not be significantly affected by wear and tear and has an extremely long lifespan. As a result, the crutches can be used multiple times without becoming unusable or unattractive.