Mechanical Kitchen Timer Project

Mechanical Kitchen Timer Project

Background

Mechanical timers are harmless devices used in kitchens that enable machinery and staff to operate precisely on timed cycles. Mechanical timers utilize relatively simple technology, including gears, springs, escapements, and a pendulum or balancing wheels, which work together to ensure the timer’s proper functioning. When the timed period has elapsed, most kitchen timers are programmed to sound a single note on a bell or gong. Mechanical clocks utilize time measurement clockwork. They are generally adjusted by turning the dial at the appropriate time interval, turning energy in the dial stores in a power supply to operate the device. They act as a mechanical alarm clock; the power source’s electricity allows a wheel to spin back and forth. For any swing, the gear train is released to shift forward by a limited fixed number, which allows it to reverse slowly until it approaches zero as a lever arm hits a bell. The following paper addresses the design and the operable functionality of mechanical timers.

1. Dismantling and Working Principles of Components of Mechanical Kitchen timer

To determine the design, functionality, and working principles of a mechanical timer, we began by dismantling the machine. This helps us to become familiar with all the components of the timer. Externally, the mechanical Kitchen timer had one center screw; we removed the screw using a screwdriver; this action removed the top cover (shell) and exposed the Mechanical Kitchen time’s inner parts. On removing the screw, there was an external plastic cover that again coated the machine’s delicate inner structure; this implies that the machine is double coated to prevent the shock of drops and any other mechanical factors that may damage the internal springs and gears of the machine. The mechanical timer’s outer cover is separated into two halves with the embedded cylindrical metallic cover that contains all the components that aid the mechanical timer to work. Therefore, we separated the first half of the plastic cover and then carefully removed the cylindrical metallic casing with the aid of the screwdriver. We were careful to avoid the screws that were directly attached to the timing mechanism of the machine. These actions were to erroneously prevent dismantling the machine to the point that of destroying its ability to function.  Since these gave us very limited visibility of the components of the machine were proceeded carefully to dismantle the inner parts of the machine that exposed the springs and the gears.

Internally it is revealed that the center shaft and the housing slots are directly fitted by the interference fit. Therefore, it implies that by twisting the center screw, we are directly opening the central axis of the timer. We removed the central cover underneath the screws to remove the metallic cover.

On opening the metal cover, we show a disc shape spring as shown in figure 5

Figure 5. Disc spring

The ends of the disc spring are clamped to the center axis and the side axis (the time axis), respectively. Common disc spring is a single axis, such as an automatic winding headset, tape measure. The central axis corresponds to the “timing” process, the “alarm axis” corresponds to an alarm process, that is, when the timing time is reached, an alarm sound is heard. Furthermore, when you twist the axis, you store energy in the spring, giving it a constant torque. As shown in figure 6;

Figure 6:

The central axis and the time axis are engaged by a gear wheel. Turning the center axis rotates with it. Such that the timer working process from an overall internal perspective follows the following principle: torsion spring> hairspring >escapement >gear set >release slowly >final bell. This implies that After twisting the central shaft, the timing structure begins to operate, the internal gear set, escape mechanism, and so on begin to run, to the end of time, the ringing mechanism begins to run.

In order to know the working principle of each step, we continued to open the machine down. It showed three screws, one of which is fixed with a small cam. We removed the screws in order to reveal the underlying internal structures of the machine.  We had two Kitchen machines; the other one was to act as physical control for the experiment. In the internal structure, we revealed that the complex part of the Mechanical timer machine is fixed with a piece of transparent acrylic, a device that is used to observe the working process and guarantee they perform conveniently and intuitively. On opening the structure, the upper part had basically the “timing axis” and “time axis,” and the shaft fixed with gears to transmit power down. These are shown in figure 7 below.

 

Figure 7: internal structures d the mechanical Kitchen Timer.

The parts indicated in the figure are the timing mechanism; the part not indicated is the ringing mechanism. In the figure, the transparent acrylic was removed as it was not part of the object.  From the figure, its timing mechanism revealed that it could be divided into three parts “gear set,” “escapement,” and “spring”; “Escapement” is the overall design of the timer and the bulk of the mechanical Kitchen Timer.  Figure 8 and 9 reveals how this escarpment works manually by pushing the gears to bring about the overall working of the timer.

Figure 8:                                                                              Figure 9:

Working (Pushing mechanism of the escarpment)

 

From figure 9, we could deduce that the timing circuit operation process works under two principles of the method. Firstly, a large gear fixed on the center shaft drives the escapement wheel to rotate through a three-stage deceleration gear. Then, the teeth on the escapement wheel propel the exit tile of the escapement fork. This action causes the entire escapement fork to move or swing.

 

Figure 10

Figure 10. Because the prongs of the escapement are engaged with the balance axis of the spring, the prong pins of the escape fork give the spring momentum

Figure 11:

When the hairspring starts to swing under the impetus of the escapement fork, and the disc on the pendulum shaft is beyond the scope of the escapement fork, the escapement is stuck by the limit pin and can’t turn. At this point, the entry tile of the escape fork can jam the escape wheel and stop it from turning.

 

Figure. 12;

In figure 12; After swinging the wire (spring) to a certain extent, it will begin to swing back under the action of its own recovery force. When the disk nail on the swing shaft is placed back in the range of the fork, it begins to drive the reverse motion of the swing fork to make the entry pad and the capture wheel go off, and the capture wheel can continue to rotate in the original direction without the “blocking” of the entry pad.

When the escapement wheel rotates a tooth, it collides with the exit tile of the escapement fork, and the workflow returns to step 1. Turning the spring gives the escapement wheel the power to turn, but the escape wheel’s rotation is always limited by the entry and exit of the escape fork. An escapement, rhythm is to follow the escapement fork walk, and escapement fork swing rhythm is determined by the hairspring, The swing period of the gossamer is fixed, so the interval between the escapement and the longitudinal is fixed. And at each fixed interval, the escape wheel always releases only one tooth! In this way, the rotational speed of the escapement wheel is constant so that accurate timing is realized.

 

Component	Purpose
Mainspring	Provide energy to drive the gear train
Hammer spring	To ring the bell once (wheel stopper) connected to the hammer reaches zero.
Balance wheel	Control the energy release by moving front and back in constant time intervals

 

2. Processes and strategies used by the team to understand the working principles of the timer.

Although there were controversies amongst us in the team, the conscious understanding, discussion, and consultations helped us mutually understand the working principle of the timer. Our team safe communications, rules, and diving responsibilities. We divided the responsibilities between the three of us, and each member was to do research on the area of assigned duty. These ensured that every member actively took part in the process.

A took part in dismantling the timer and taking into account different physical structures present in the timer. B and I took part in separating the components and identifying some of the external and the internal structures within the timer. Then we collectively took part in interpreting how these physical components worked together to bring about an alarm sounds: “Dong” in the timer. Finally, I took part in reassembling all the parts we had we had separated into a full standalone product again. All these were guided by discipline, safe communication, and commitment to delivery.

3. Similarity and differences between timer and clock

The main similarity between a clock and a timer is that both can be used to measure timed variables. But a timer is a specific clock type used for time periods calculation. It counts time elapses from zero upwards. It counts from a certain time span and is used to produce time duration. While a clock calculates, preserves, and specifies the time. The difference is that a timer has the capability to be set on a regular basis, such as triggering an interrupt, commanding hardware to adjust some pin value, or even reset the timer itself; these activities in most cases cannot be done by the clock. Initially, I had misunderstandings that clocks are the same as timers; this has been proved to not be true by the help of my colleagues.  This has improved my initial knowledge about timers and clocks; although their functionality roughly resembles each other, they completely mean different things addressed in different platforms.

4. Instances of differing opinions.

There were differing opinions on two different occasions. The first deflection was during the planning, and the second one was during execution.  During planning processes, members were not willing to take up the responsibilities assigned. For instance, A was insisting on doing the work allocated for B (Working on the gears and springs of the timer) since he had a feeling that B was not competent for it. As a project team, we discussed the need to be compact in order to finish, and it went on successfully.

5. Individual team members strengths and weakness

As a team member, I can comment that the success of the project was based on the members. The social strengths included the ability of the ream to communicate openly with each other over the project.  Secondly, all the teams were focused on the goals of knowing the design and functionality of the timer; therefore, both gave their time on the project. Every member did to the best of the allocated quotas on the project. A did the best in dismantling the outer and the inner casing, B perfected in identifying the connection of the gears, springs, and escapement, and I did the best in examining the patterns of movement up to reassembling It.  All these were possible due to a good leader, high level of organization, and support of each other. Despite the success, there were minor weaknesses among the members. B was overcritical to the point where he wanted to take A’s tasks. Both A and B required constant reminders to push them to avail themselves during the project time; this made the project progress a bit slow.

6. How our team performed in the project

Our team delivered the best in the project; this can be traced from the period this can be traced from the project was initiated, up to the time when it ended. The successful completion of this project showed all members knowing the design and functioning of the timer. This was achieved in time with minimum cost. Furthermore, it facilitated by the project team favorable attributes such as effective communication that maintained cohesion, collaboration, and cohesion of members.

 

 

 

 

 

 

 

 

 

References

Barr, R., Krueger, T., Wood, B., Aanstoos, T., & Pirnia, M. (2009). Introduction to Mechanical Engineering Design through a Reverse Engineering Team Project. In Proceedings of the 8th ASEE Global Colloquium on Engineering Education (GCEE).

Sharon, T. (2020). U.S. Patent No. 10,750,903. Washington, DC: U.S. Patent and Trademark Office.

Snider, C., Gopsill, J. A., Jones, S. L., Emanuel, L., & Hicks, B. J. (2018). Engineering project health management: a computational approach for project management support through the analytics of digital engineering activity. IEEE Transactions on Engineering Management, 66(3), 325-336.

Xu, J., Li, B. K., & Luo, S. M. (2018). Practice and exploration of teaching reform of engineering project management courses in universities based on BIM simulation technology. EURASIA Journal of Mathematics, Science and Technology Education, 14(5), 1827-1835.