SILVERWARE / NAPKIN ROLLER
Georgia Institute of Technology
The George W. Woodruff
School of Mechanical Engineering
ME4182 Capstone Design
Summer Semester 2001
The Cutting Edge:
Professor: H. Lipkin
25 July 2001
The intention of the design team for this project was to design a fully automated machine that would roll silverware in a cloth napkin for restaurant applications. The device would take in a stack of freshly cleaned napkins as well as sets of clean utensils and process the inputs such that a rolled napkin would be dispensed into a container. Such a machine was not common at the time of this project, and the group felt that such a device would have considerable market appeal. Currently, most restaurants use the wait staff to handle such a chore.
For time purposes, at the request of Dr. Lipkin, the group partitioned the device into various sub-functions and chose the rolling and dispensing sub-functions as the primary goals of the project. Both sub-functions were achieved both in design and in prototype. Also, a crude timer circuit was designed for the two sub-functions in order to automate the steps. The timer was not implemented due to material constraints.
As it stands, the group has achieved its goal, and a prototype has been created that takes an already placed and folded napkin as well as an already placed set of silverware and rolls the silverware tightly into the napkin. The rolled product is then dispensed to a holding area and the machines is then reset for the next process. Future considerations for this project would be to devise methods for completing the remaining sub-functions, such as folding the napkin as well as placing the napkin and silverware in the correct positions. As it stands the device is not ready to compete with human workers until these sub-functions are addressed.
The project selected by the group was to design an automatic silverware / napkin rolling machine. The machine would automate a currently manual process. Such a machine would take one fork, knife, and spoon, and roll them up in a napkin. The goal of such a device would be to make the process fully automated with a process speed comparable to that of the average worker.
Several constraints will define the project. The machine should be fully automated with worker input limited to adding a supply of silverware and cloth napkins. The machine, if possible, should be able to accommodate several varieties of silverware and napkins. Delays and mistakes should be minimal. Maintenance of the machine should be simple and inexpensive. Sanitation and ease of sterilization is a must. The size of the machine must be such that an existing kitchen can accommodate it. The machine must be safe during operation. The machine should be quiet as is necessary for a restaurant atmosphere. For the purposes of this course, the time allowed to complete the design process restricted the team to designing only the "rolling" sub-function of then entire process.
The project was a systematic design process to create a solution. Solution ideas were evaluated. Matrix methods such as a house of quality were employed. One method was chosen and the design work began. After the design was completed, the mock-up was built in order to show the functionality of the design. A final prototype was constructed. The progress and success of the project were reported throughout the course. The group focused on rolling and dispensing the napkin due to time constraints.
Such a product would have a strong market value. In restaurants, employees are usually put to work after closing time, folding and rolling up napkins for the next day. This forces the owner to pay more money for employees to be involved in activity that is time consuming, and so labor cost is considerable. If a machine were invented that could automate the process, the labor cost would be virtually eliminated, and the napkins could be rolled with accuracy for the next day's customers. The novelty of such an invention is obvious, since no similar process or machine exists commonly today.
In the beginning, there were five ideas. One idea was a ‘Hands Free Toilet Flush,’ which would attach to any existing toilet handle and would return slowly by way of dashpot to eliminate the need to stick around to hold the handle down. Another idea was an automated coffee maker with dispensers for cream and sugar. It was hoped that a user could punch in varying amounts of additives and the machine would ad the appropriate amount. Another idea was an automatic toilet paper roll loader that would eliminate the need to replenish the toilet paper supply in public restrooms. Rounding out ways to make the bathroom a better place was the automatic toilet seat cover dispenser. All of these ideas were eliminated because they existed in one way or another. The idea of the sock roller was tossed out because of the impracticality. The overall difficulty of dispensing the proper amount of liquids saw to the demise of the auto-bartender. In the end of the first session with the advising professor, it came down to two ideas: a garden hose winder and a silverware/napkin roller. The novelty of the silverware/napkin roller captured the design team’s collective eye.
Once a product was decided on, the team needed to figure out how to approach the solution. The design presented many challenges in the early stages. In order to break these down in to manageable chunks, the group came up with a design partition that would show the steps of the process of completing a rolled napkin with silverware inside. The design partition is shown here in Figure 1.
Figure 1 First level of the design partition
As can be seen in Figure 1, the finished product requires four preliminary steps. First, the clean napkin must be positioned. Next, the silverware that is to be rolled in to the napkin must be positioned. Once that has been completed, the napkin must be folded around the silverware. Finally, napkin must be rolled and dispensed.
In turn, these steps can be broken down further. In order to position the napkin, something to grab the napkin from a pile must be designed. Once in the device’s grip, it must be able to place it on the folding table. Grabbing a single knife, fork, and spoon is a necessary step to positioning the silverware. The silverware must also be placed in the proper area of the napkin. The rolling of the napkin is broken down in to the actual rolling of the napkin and the dispensing of the rolled product to a bin.
It was suggested by the advising professor to tackle a few of these tasks due to the difficulty of the complete project and time constraints. The group decided to focus on folding the napkin, rolling the napkin around the silverware, and dispensing the napkin /silverware roll given the napkin and the silverware was positioned. In the future, other tasks might be completed.
Now that the project had been broken down in to tasks, the team needed to decide on some mechanisms to accomplish the tasks. Three conceptual designs for doing the initial fold of the napkin and three conceptual designs for rolling the napkin around the silverware were put together. In addition, a machine that would fold the napkin in to a more place-setting style was conceptualized.
The Belt Roller is shown in Figure 2. The Belt Roller was based on the existing technology of a cigarette roller. As can be seen in Figure 2, Roller A moves towards Roller B to form a trough in which the silverware will get rolled. Once the product is rolled, Roller A moves out and the product can be picked up or rolled off. This is the method embraced because the group could see it in action.
Another design concept was the Three Pronged Roller. It is shown in Figure 3. The napkin would be intertwined around the rollers. A motor attached at the hub of the rollers would roll the napkin and silverware. This method was thrown out because of the complexity of the device.
The last conceptual design of rolling up the napkin was a bit radical in its approach to the problem as can be seen in Figure 4. The Spatula-Pocket Method required a newly designed napkin. Two spatulas would engage the pockets, which would have to be sewn in to the napkins, and they would roll up the napkin around the silverware. This method was thrown out because of the complications involved with redesigning a napkin.
Figure 2 Sketch of the Belt Roller
Figure 3 Sketch of the Three Pronged Roller
Figure 4 Sketch of the Spatula Pocket Method
One of the ways of tackling the initial fold task of the problem was the Edge Folder pictured in Figure 5. It was thought that the mechanism could be actuated with a solenoid in much the same way that a trash can lid is actuated by a foot pedal.
Figure 5 Sketch of the Edge Folder
This is the way that the group decided to employ to fold the edges because of its apparent ease of actuation.
Another way to fold the edges was dubbed the Yanking Vortex. One of group members had experience with a similar device that folded paper wrapping around wires. Figure 6 shows that the napkin would be drawn through the ‘vortex.’ It was decided that this piece would be too hard to manufacture, so the idea was tossed aside.
Figure 6 Sketch of the Yanking Vortex
Figure 7 Sketch of Recessed Folder
It seemed the group’s habit was to come up with at least one radical idea for each task. The Recessed Folder was the radical idea for folding. Basically, the napkin would be dropped on a table with raised edges. Under the raised edges would be arms that would be actuated with solenoids to push the folds over the silverware. Figure 7 is kind of busy, but the basic idea can be seen. It turned out that this idea was too radical even for the group.
The last conceptual design theoretically completed the task. This mechanism would not roll up a napkin. Instead, it was thought this idea would fold up a napkin in to a rectangle as in traditional place settings at one’s home. The group laughed at this idea much to the chagrin of a group member. It is pictured in Figure 8 showing the folds that the mechanism would make. This method was thought to be completely impractical. The group member had the last laugh because there was a patent on a very similar idea.
Figure 8 Sketch of the Three Hinged Folder
FROM CONCEPT TO ‘REALITY’
The group had extensive meetings in which the focus was agreed upon. Once the group had agreed on the belt roller for the rolling device and the edge folder as the folding device, it threw the edge folder aside to focus on the task of rolling and dispensing the napkin. The group also added the task of automating the processes.
The device shown in Figure 9 is a simple drawing of the machine in its entirety. The box on the left shows the rollers in the fully apart positions. The box on the right shows the rollers together. The blue box on the back of the machine houses the power supply and associated wiring. The silver roller is the driving roller that is responsible for moving the belt, which is pictured in yellow. The green boxes on the sides house the belts and motors that move the roller toward and away from the driving roller. Earlier in Figure 2, the moving roller is referred to as Roller A. The purple box is just support and tracks for the moving parts.
Figure 9 The Napkin/Silverware Roller
Since the machine is to be operated in the food service industry, materials must be easily sanitized. The belt will be some sort of rubber similar to that at checkout counters in grocery stores. It can not be absorbent of liquids since it must come in contact with (for the most part) white napkins. The other parts will all be stainless steel. Some lightening holes will be added to reduce weight and cost of materials.
First of all, all of the information in this report and more can be found by browsing through the group’s website. The machine designed this semester does not in any way meet requirements for immediate entry to industry. The machine designed accomplishes the two tasks of rolling and dispensing of the rolled napkin and silverware. For this machine to be industry ready, mechanisms for placing napkin, placing the silverware, and making the initial fold must be added. The group and the advising professor felt that those tasks would have made this project too difficult for the time allowed. Be sure to thank the hosts and hostesses for rolling your silverware.