**3.2.3 Team building**

196 Reverse Engineering – Recent Advances and Applications

Develop a lock system, easy to use, compared to the current model for the oven EC10.

**Cycle Description Purpose** 

<sup>1</sup>Check the types of lock used in the company, obtaining virtual drawing, access to the lock, take them apart and collect as much data as possible.

Interview the chef cooks of the company. Ask him about the current factory lock system: what´s the best? What are the pros and cons of each one? Do they accomplish or not the expected from the system? What

It´s been sought as much as possible information about industrial ovens available on the market. It´s been got reference locks analysis, according

It´s been start the design of parts, with the help of software, taking into account all collected information, as well as the use of DFMA principles

After completing the drawing, they were presented to the engineering manager and to the chef cooks, for the mechanism approval. With the requested items modified, finally came an ideal conceptual design.

It´s been made the assembly of the hybrid prototype and verified the validity of the mechanism, which has been presented to the engineering manager, as well as the chef cooks, for approval. It´s been analyzed possible needs for changing and necessary changes made in the

<sup>9</sup>It´s been asked the manufacturing, through machining, of metal parts and

A door has been built up with the needed slot for testing with the new locking system. An oven for testing had been set up on the door and the available oven. Alignments and adjustments were necessary in the components. The mechanism has been tested several times. The results were presented to director, engineering manager, chef cooks and the

Problem were identified and possible needs for improvement. Companies that reduced the samples of springs and machining of parts have been contacted, in order to improve results with the springs and simply machining. The machining company was visited for contacting with the

Finally, it´s been chosen the product. More locking prototypes have been made. Pneumatic devices were created for the product prototype wearing. Prices for large-scale production have been negotiate and ordered to produce the locks in the manufacturing process best suitable

Two reference ovens have been identified. One from a German company, a direct competitor in Brazil, and another one from an Italian company, that makes different

Reference locks have been disassembled and one learned how the systems work. The manufacturing processes were identified, facilities and difficulties to assemble and disassemble were realized. In a word, all the

to ensure facilities for manufacturing of parts and assembly.

could be changed? What is a good difference?

data was collected to start the new design system.

7 The parts have been prototyped for testing.

springs to the purchases responsible.

responsible and creation of goal for improvements.

Table 2. Summary of the conduct action-research cycles in Company A

to reverse engineering.

conceptual model.

purchases responsible.

for each part.

**3.2.1 Identify the opportunity** 

2

3

4

5

6

8

10

11

12

The formed research team was composed by the chef cooks, engineering manager, plant manager, purchases responsible, and the researcher, who supplied the necessary information in all areas. Each one of the participants of the company has more than five years of experience in the development and manufacturing of ovens.

#### **3.2.4 Disassemble (information about the product)**

As for the locks used in the company, their virtual drawing was used, allowing to analyze each one regarding the assembly and each part separately, without having to disassemble the product.

The locks of the German and the Italian ovens were disassembled and analyzed. Through photographs, important information was stored.

Table 3 shows the comparison between the current model EC10 oven lock system and the proposed system. To monitor the work, its whole operation has been registered in virtual drawing, photos and videos, focusing on further analysis.


Integrating Reverse Engineering and Design for Manufacturing

component Material: Plastic Manufacture: Foundry Function/feature: set on the side panel with the function of holding the propellershaped shaft and through friction, limits the movement and seals the oven chamber.

Name: Washer Material: Brass

function.

Manufacture: Machining Function/feature: washer

Name: Plate washer Material: Steel

Name: Allen screw Material: Steel

component.

Name: Sphere Material: Steel

stage.

Manufacture: on the market Function/feature: to ensure there is no slack in the machined Allen screw and also allows its sliding.

Manufacture: on the market Function/feature: to fix the handle on the rotating

Manufacture: on the market Function/feature: It remains housed in the rotating component, partially occupying the base holes, at the moment the locking function happens at every

Name: Conical shaft locking

and Assembly in Products Redesigns: Results of Two Action Research Studies in Brazil 199

**BEFORE AFTER** 

Name: Two-staged locking

Proposed material: Steel Proposed manufacture: Foundry and machining Function/feature: fixed in the oven frontal side. It ensures a complete sealing of the oven chamber or a relief stage for

releasing steams.

Proposed material: Steel Proposed manufacture: On

Function/feature: Beyond the function of washer, it is used on the two staged lock to ensure positioning adjustment.

Proposed material: Nylon Proposed manufacture:

Function/feature: to ensure the rotating component positioning inside the base and avoid the friction between both.

Name: Allen Screw Proposed material: Steel Proposed manufacture: to fix the shaft/spring base on the rotating component, through the nut on the handle, which will be fixed on the set at this

Name: Shaft/spring Proposed material: Stainless steel and spring steel. Proposed manufacture: machining and spring

Function/feature: next to the two stages lock, it allows the complete sealing of the oven or the lock in the second stage, which allows the door to be relieved for the release

Name: Washer

Name: Bushing

Machining

moment.

adjustment.

of steams.

the market

screw


198 Reverse Engineering – Recent Advances and Applications

**BEFORE AFTER** 

Name: Base

Foundry

snap ring.

Foundry

system.

market

Name: Snap ring Proposed material: Steel Proposed manufacture: on the

for the movement.

Name: Base of the shaft/spring

locking function.

Foundry

Proposed material: Steel Proposed manufacture:

Function/feature: fixed on the spinning component through the screw. It ensures the positioning of the shaft/spring, so that it remains the same with the necessary deformation for the

Proposed material: Steel Proposed manufacturing:

Function/feature: device to be mounted on the door from inside. It works as a knocker to stop rotating drive system, in addition to host the return spring, nylon bushing component of the spin and

Name: Rotating component Proposed material: Steel Proposed manufacturing:

Function/feature: it remains inside the base of the lock; it moves fast returning springs, it is limited by rotating movements with knockers, it makes connection between the handle and the locking

Function/feature: it ensures the positioning of the rotating components within the base, while keeping the clearance

Name: Base

welding.

system.

Material: Stainless Steel Manufacture: Laser cutting, bending, machining and

Function/feature: device to be mounted in the side door. It works as a knocker to stop rotating the drive system, ensure different stage of positioning for the set through the holes and supports other parts of the

Name: rotating component

Name: Machined Allen screw

Manufacture: machining Function/feature: machined part serve for fitting the screw fly; it ensures he attachment of the nonrotating component at the base, keeping the clearance for the movement.

Material: Steel

Name: Screw fly Material: Steel

part.

Manufacture: On the market Function/feature: screwed into the rotating component with the function of limiting the movement of the machined Allen screw, precisely by the machine

Material: Bronze Manufacture: machining Function/device: it gets the rotating handle movement and locks the oven door through the conical propeller-shaped shaft.


Integrating Reverse Engineering and Design for Manufacturing

Fig. 6. Prototyped components of the proposed lock system

Fig. 7. Exploded view of the proposed design concept for a locking system

and Assembly in Products Redesigns: Results of Two Action Research Studies in Brazil 201


Table 3. Comparison between the current system and the proposed one for the oven lock.
