Umbrella 2

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Contents

Executive Summary

Our team chose to analyze a standard collapsible umbrella. This decision was prompted by an acknowledgment that the device is widely used, has many variations and its universal application as a rain protection device. We conducted a study to illustrate proper use and operation, but also to discover what and when issues arise with an umbrella. As expected, most of our concerns were centered on different ways that the umbrella can fail to keep its user protected from precipitation, but also with durability in response to repeated elemental punishment or daily use. Performing a product dissection, enabled us to tabulate all individual components based on part weight material and other relevant metrics, and sub-assembly analysis gave us significant insight into how and why an umbrella might fail and how that is directly related to its design and manufacturing processes. In analyzing the different possible modes of failure, we confirmed that almost all problems are either with canopy tears or removal, or dynamic breakdown, i.e. the umbrella will no longer open and/or close properly due to plastic deformation of components. Analyzing the manufacturing processes and involved costs showed us why we were observing these problems. Umbrella convenience was linked heavily to weight, size and cost, the optimization of which necessitates using less material, especially in structural components like the spokes, which reduced the umbrellas durability. Thus, when an umbrella canopy inverts, the spokes likely suffer some deformation or weakening when the user flips it back to the proper configuration, leading to a shorter umbrella life when a part eventually fails. If, however, along the lines of a cobbler, there were provisions for umbrella repair, we believe more efficient materials could be used in manufacturing as users could justify the increased cost paid as they saw associated life extension. All in all, we predict that we will not truly be redesigning an umbrella per se, but more likely an accompanying device which either dries or in some way repairs common issues, if we find that the market is ripe for such developments.

Major Stakeholders and Product Needs

Consumers

  • Appealing
  • Durable
  • Lightweight
  • Effective
  • Safe
  • Easy to use
  • Portable
  • Inexpensive
  • Comfortable to hold
  • Easy to clean/dry

Retailers

  • Ease of storage
  • Cost/Profit
  • Durability
  • Customer Satisfaction

Product Function

The operation of this particular umbrella was very simple. The pictures below depict the general use of an umbrella.

Hold Umbrella and unwrap
Hold Umbrella and unwrap
Extend Telescoping Shaft and push upwards on Concentric Tube
Extend Telescoping Shaft and push upwards on Concentric Tube
Expand Spokes
Expand Spokes
Position Umbrella upright for use and hold
Position Umbrella upright for use and hold

The umbrella consists of a handle which is connected to a telescoping shaft. The telescoping shaft is a mechanism that extends in order to expand several mechanical arms, or spokes, outward when the umbrella is in use. The extension of these spokes serves to expand the canopy, made of polyester, producing a dome shape. This dome shape deflects rain and snow from reaching the user. The concentric tube is located at the top of the shaft. It holds the spokes firmly together and is used to extend the telescoping shaft. There is a locking mechanism also located at the top of the telescoping shaft so that the canopy does not close when the user is holding the umbrella. To collapse the umbrella, the concentric tube is pulled downwards to shorten the telescoping shaft and contract the spokes. The umbrella is then stored.

To use an umbrella the following steps are taken:

Steps

The following link shows a consumer opening an umbrella for use: Umbrella Use

The following link shows a consumer closing an umbrella after use: Umbrella Close

Usability Study

After using this particular umbrella, numerous issues have been encountered. The polyester material is very loosely connected to the spokes. This results in an ineffective umbrella where the area of coverage from preciptation is decreased. Furthermore, the spokes of the umbrella was observed to have many moving parts. The outcome is a sacrifice in strength. A common outcome is bending of the spokes due to excessive winds. We noted that a stronger mechanical design for the spokes was needed for the umbrella. Additionally, precipitation contacted the user during use when high winds was present. During our study, snow reached the user in a direction perpendicular to the position of the umbrella. This also diminished the effectiveness of the umbrella. Finally, storing and cleaning the product was a major issue. It was observed that after use, many users commonly shake off the excess water from the umbrella onto the floor of the location they enter.

The following video shows a typical use of using an umbrella. Water is often shaken off onto the floor after use. Umbrella Wet Floor

Mechanical Function

There are 2 mechanical functions of the compact umbrella. The first is to extend and contract the shaft of the umbrella. How this is done is by making the shaft telescoping. Three separate metal shafts are connected together and are allowed to collapse into itself. When the shaft is extended it is held in place by 2 ball bearings for each connecting shafts. These ball bearings lock into place and prevent each individual shaft from moving. The second function is to open and close the canopy of the umbrella. This is done by the use of a four-bar linkage which consists of the spokes, spokes support and concentric tube. The concentric tube controls the extension and contraction of the spokes. As the concentric tube is pushed up the shaft the spokes extends and vice versa. The 8 spokes supports are connected to the concentric tube by a steel wire.

Bill of Materials

Part Number Part Name QTY Weight (g) Function Manufacturing Process Material Image
1 Cap 1 < 1 Holds the canopy to the telescoping shaft Injection Molding Plastic
2 Screw 1 1 Attaches Cap to Canopy Formed Steel
3 Cover Bag 1 3 Storage Hand-Stitched Polyester
4 Handle 1 20 For a comfortable hold on the telescoping shaft Injection Molding Plastic
5 String 1 1 Allows device to be held from the wrist of the user Threaded Polyester
6 Canopy 1 39 Deflects Precipitation Hand-Stitched Polyester
7 Plastic Skirt 1 < 1 Prevents Precipitation near the Cap Cut Plastic
8 Thread 1 1 Holds Canopy together with Steel Cap Open Polymerization Polyester
9 Spoke Sub-Assembly 8 20 Provides structure of the device Pressing/Stamped Aluminum
9a Steel Cap 1 1 Holds Canopy together with Spokes Casted Alloy Steel Alloy
9b Aluminum Wire 1 < 1 Prevents Spoke Assembly from bending Machine Shaping Aluminum
9c Spoke Links 4 3 Extends Canopy Pressing/Stamped Aluminum
9d Connecting Spoke Link 4 1 Connects Spoke Sub-Assembly to Steel Cap Machine Shaping Aluminum
10 Concentric Tube 1 4 Allows Spokes to extend for use Injection Molding Plastic
11 Telescoping Shaft Sub-Assembly 1 25 Extends device for use and main support Pressed Aluminum
11a Top Clip 1 < 1 Allows Telescoping Shaft to disengage and shorten in length Pressed Aluminum
11b Concentric Tube Holder 1 1 Holds Concentric Tube in place Injection Molding, Pressed/Stamped Plastic, Aluminum
11c Shaft Clip Spring 1 < 1 Locates and locks Top Clip Pressed Aluminum
11d Telescoping Shaft Link 2 12 Allows device to be extended and adds support to device for user Pressed Aluminum
11e Ball Bearings 4 < 1 Allows Telescoping Shaft to extend to various lengths Casted Steel
12 Steel Wire 1 < 1 Holds Spokes together in Concentric Tube Machine Shaping Galvanized Steel

Assembly Diagram

The image below depicts the major components of the product.

The image below shows a more detailed look at the more intricate portion of our product.

Design for Environment (DFE) Analysis

When designing any product, engineers must address the potential impact on the environment during the product development process, use phase and its recyclability. We conducted a Design for Environment analysis or DFE, to discover the ways in which umbrellas affected factors like gas emission and waste production. We aimed to identify the environmental impacts by utilizing an input-output product life cycle assessing tool,(EIO-LCA), of an economic sector defined as "Other fabricated metal manufacturing". Furthermore, we strove to determine the impact on the cost of production if Congress were to pass a tax on CO2 emissions. This was accomplished using Carnegie Mellon’s EIO-LCA website. We recorded the greenhouse gas emission levels and toxic releases associated with our product's production sector, assuming 1 million dollars of economic activity was used in the sector: #33299C: Other fabricated metal manufacturing. We concluded that this sector best represents our product as it includes the main material used in its life cycle, the product's majority raw and processed material being aluminum. Although our product does contain a textile component, we chose not to include the textile manufacturing sector in our analysis as the umbrella contains mostly aluminum by weight, and after preliminary research it seemed that the production costs and gas emission were negligible relative to the aluminum's impact in those categories. During our analysis, we concluded that there were no real external energy inputs during the use phase of the umbrella, as personal use is arbitrary and up to the individual. Therefore, we have chosen to disregard an examination on the potential impacts on the environment from umbrella usage.

Energy

The table below shows that for every additional 1 million dollars spent in the sector, "Other fabricated metal manufacturing", there is a corresponding energy use increase of 12.5 TJ.

Steps

These results show that the primary component of this increased energy is due to Power Generation & Supply which accounts for approximately 25% of the increased energy.

Steps

Greenhouse Gases

The table below shows that an additional 1 million dollars spent will result in an increase of 839 metric tons of CO2 Equivalent (MTCO2E).

Steps

The results indicate once again, the large role of the Power Generation & Supply sector. This sector is responsible for nearly 31% of the increased emissions. However, the sector that contains our product has a smaller role. The Other fabricated metal manufacturing sector contributes about 7% of the increased emissions.

Steps

Toxic Releases

An additional 1 million dollars spent in the sector, Other fabricated metal manufacturing, will also result in an increase in toxic releases by 703 kg.

Steps

Results of our analysis indicate that the Gold, silver, and other metal mining sector is responsible for an overwhelming 91% of the increase in amount of toxic releases. The sector, Other fabricated metal manufacturing, is only responsible for approximately 1% of the increased toxic releases.

Steps

Life Cycle Assessment (LCA)

The emissions associated with umbrella manufacturing from the sector: #33299C: Other fabricated metal manufacturing are presented in the table below. The table also shows what the implied CO2 tax will be assuming Congress passes a tax of $30 per metric ton equivalent of CO2. Again, we concluded that there are no known energy inputs during the use phase of the life cycle assessment, aside from that of the user. Therefore, we have chosen to disregard umbrella usage from the life cycle assessment.

Steps

DFE Conclusion

Based on the results of the Life Cycle Assessment, we concluded that most of any life cycle improvements would be in the manufacturing processes, and specifically in the amount of, and methods used to manipulate, the aluminum components, or else in a dynamic shift in user behavior. This conclusion seemed reasonable, as we assume that there will always be some sort of canopic textile, and that umbrellas will presumably not begin to utilize noticeable energy during their use phase, but people may be convinced to repair a more expensive model or require a drying device to increase their convenience. The sector, Power Generation and Supply, is mainly responsible for the release of GHG emission. If this product were to be redesigned to reduce GHG emissions, energy supply can be produced from renewable sources such as wind turbines or solar cells.

Although choosing to mostly ignore the end life processing in our analysis, we believe that a significant difference can be made through the implementation of a recyclable design, or a more durable overall design, and that GHG emissions can be lowered. If more umbrellas stay in use, then less will be purchased, and presumably demand decrease will necessitate supply decrease and less manufacturing means less power usage and consequently emissions, while also easing the burden on landfills, and raw materials gathering. Furthermore, if Congress were to pass a carbon tax on this product, it's effect can be considered negligible. A $0.19 tax will result in an increase of the product price of approximately 3%.

There is some uncertainty to our assessment. Again, we have decided to not include textile manufacturing for the polyester component of the product since the umbrella mainly consists of aluminum by weight. Furthermore, there was not a precise sector that could be used when using Carnegie Mellon's EIO-LCA website. However, we are confident in our recommendations.

DFMA

We did not concentrate heavily on the DFMA analysis, as many of our parts could be made in various ways, but we assumed that the porcess had already been streamlined by producers as cost reductions is paramount for some. Also, variation in designs make it difficult to suggest an overall manufacturing or assembly improvement. We did think that the steel umbrella tip could be integrated into the final finger spoke linkage to reduce components, but also that a more secure method of canopy attachment was necessary. Perhaps using a snap in type plastic component that functions similarly to a drywall screw would help strengthen this point. Also, if the hand sewing connecting point was no longer necessary, transportation to a human labor processing center would be eliminated reducing labor and travel costs, as well as any possible middle man transactions. Even though we analyzed one umbrella design and could suggest improvements upon it, all the candidate improvements we considered were exhibited in other existing umbrella designs so we decided to focus more on user and end life improvements.

FMEA

The conventional compact umbrella was designed for portability and cheapness. However in doing so durability and robustness is sacrificed. The parts with the highest RPN number was found to be at the spokes sub-assembly and the canopy. These 2 parts are the most likely parts that fail and break in the lifetime of an umbrella. The spokes are lightweight and very flimsy and tend to bend and break from either impact or wind resistance. The canopy tends to rip and tear in the connection joint of the spokes and canopy. The spokes can be made more robust and also be lightweight if less parts were used for the assembly and if different material was used. For the canopy instead of using threads to tie it to the spokes, a clip on attachment or velcro will be suffice.

Conclusion

While a number of improvements could potentially be made for an umbrella design, we also acknowledge that a cheaper but less durable umbrella will continue to be a part of the market despite greater quality being available. We believe that this is mostly due to what we suspect as customer ignorance of overall purchasing impact of what is comparable to one time use products or personal taste, i.e. paper plates over ceramic. We would like to do more research into consumer habits and ideology to determine if this is a point worth addressing in the overall umbrella market and lifecycle improvement. In the specifically mechanical sense, we found greater difficulty in suggesting specific improvements, as an enormous variety of designs of differing mechanical basis are used in the market. Regarding the design we dissected, it seemed that some parts could be condensed into fewer components, or that use of a stronger or thicker overall material would improve umbrella life, but we recognized the inherent cost increases associated with these changes. We especially saw this when using the EIO-LCA to extrapolate the increased manufacturing costs. Because we know there are so many variations of umbrellas, some optimized for cost, some convenience, we saw that no one variation could ever address all potential issues, and that similar to spaghetti sauce or gum flavors, different varieties were a necessity based on consumer need and variety demand. In summation, we learned a great deal about what factors determine producer and user costs, which materials and processes impact the environment most, and how “green engineering” is not simply a responsible choice, but also should be accompanied by an associated economic trend towards recyclability for more cost effective products. We believe that the current lack of efficient end life processing, and the fact that simple reversible failure modes are not being addressed, canopy tear patches, bent spoke realignment, are the areas which an umbrella production market need to be concerned with most.

Team Member Roles

Jasen Kim: Mechanical Function, FMEA

Jorge Moncayo: Stakeholders, Product Function, Usability Study, Bill of Materials, DFE

Kristoff Mauclaire: Executive Summary, DFMA, Conclusion

Item and Function Failure Mode Effects of Failure Causes of Failure Design Controls S O D RPN Recommended Actions
Handle - Allows for user to hold umbrella Fracture Cannot hold product and potential danger Impact Material Strength 7 2 1 14 Use stronger material
Telescoping Shaft Sub-assembly - Extends and contracts the umbrella for portability Fracture Product inoperable and potential danger Impact Material strength 9 4 1 36 Use stronger material
Rust Poor Aesthetics Corrosion of material Material Coating 3 3 3 27 Use better coating
Concentric Tube - Holds the spokes and ribs in a circle and opens/closes umbrella Fracture Product inoperable - Spokes cannot be held in place Impact Material Quality 7 2 2 28 Use different material
Spokes Sub-assembly - Holds the canopy in a dome shape Bend/Twist Cannot hold canopy in place properly Impact and wind resistance Manufacturing 9 8 1 72 Redesign linkage and use stronger material
Cap - Holds canopy in place and prevents water from leaking Fracture Water will leak from top Impact from dropping Material Strength 3 5 4 60 Use metal instead of plastic
Steel Connecting Wire - Holds the Spokes and conenctric tube together Fracture Umbrella will be ineffective Fatigue and wear Durability Testing 7 2 3 42 Use stronger material
Top Clip - Prevents the concentric tube from falling down the shaft Bent/Fracture Will not be able keep the umbrella open Impact Material Strength 6 3 3 54 None
Canopy - Covers the user from rain Rip/Tear Water will leak onto user Impact/extended use Durability Testing 8 9 1 72 Use stronger textile
Steel Cap - Holds Spokes sub-assembly and canop together Fracture/Bend Will not be able to extend canopy Extended Use Durability Testing 5 2 3 30 Redesign steel cap
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