Group 22 - Swingline Electric Stapler

Executive Summary

Modern technologies have improved rapidly during the last half of the 20th century. Nowadays, engineers have to consider many factors before creating products. The success level of products have to be based on the advanced use of technologies in the products, its design, how convenience to use it. Such great products as iPods with a compact and beautiful design , friendly user interface have tremendous popularity in the consume’ world.

With those ideas in mind, our projects’ mission is dissemble a Swingline portable electrical stapler, analyze features and based on that to improve the product. Our first impression of the product is that it’s very easy to use. With a compact, sleek design , it’s very eye-catching. It is electrically power with a dual power source of AC adapter and battery-generated gives it great mobility. A stapler remover is also included within the stapler, give users great convenience. As we dissembled the stapler , we found that it has a very simple design. Its principle technology is just basic mechanical technology in a smaller version. When the a stack of document is placed under the staple area, the document touch a little metal sensor which then trigger a switch within the stapler, instantly close the circuit in the circuit board which send the signal to the motor. The motor finally spin, move small gears that are connected to it, finally staple the document. All of these lengthy process happen within microseconds. This feature of the stapler can be disabled by using a manual switch on the left side of the stapler. The user then can trigger the motor to run through a small button on top of stapler.

It took us no time to dissemble the product and also put them back together. However , it has many delicate parts that can be easily broken. Many of its parts are not so popular so once the stapler is broken, it’s very hard to fixed. As we dissemble it , the black wire that connect the motor and the mother board actually fell off, which basically disable the entire product. We haven’t been able to fix it since then. After analyzing the products, we come to some conclusions and also improvement suggestions:

• Better housing of the wires
• Better design for the stapler slide to avoid jamming
• The lever of the stapler should be raise of even slide to side way so it can staple bigger documents, which means the addition of a stronger motor.

Introduction

Our product is a Swingline portable electric stapler ( Model #42130). It has many great features such as auto or manual staple documents, dual power source of 12V DC power( generated by a 110V AC adapter) and also it can run on 6 AA batteries

As for this projects, our group consist of four members:

David Irving: group leader, in charge of direct the group, he also work on the CAD drawing and the oral presentation

Mike Wulff: in charge of the written report and also the oral presentation

Tuan Nguyen: in charge of the written report and also the written part of the oral presentation

Nick Martin: in charge of dissemble and assemble the product

• All members dissemble and assemble the product.

Before Disassembly

Purpose of Product

The purpose of the Swingline Electric Stapler is to provide a way for a user to bind papers together with a staple without requiring any force to be applied by the user.

How it works

When paper is put into the stapler, it presses on a trigger. When the trigger is activated, the stapler arm is pressed down and a staple is driven through the papers. A metal plate under the papers bends the staple to prevent it from unintentionally coming off.

Types of Energy Used

The stapler converts electrical energy (in the form of DC current from a battery or converted from AC current from a wall outlet) to mechanical energy that is used to force the staple through the paper.

Product Operation

Before disassembly, staples were put into the staple tray, and the product was tested. The product ran as expected, stapling a small stack of papers together without problems. As it operated, a blue LED light flashed at the base of the stapler. The plastic casing didn't move at all during operation, just the metal stapler arm. A low noise could be heard, probably coming from motors and gears operating.

Components

Before disassembly, we expected to find about sixty components in total in the stapler. We felt this was a reasonable number because we expected there would be many small parts needed inside the stapler. We expected to find five different materials used to make the various components, with most of the parts being plastic or a type of metal.

Disassembly Procedure

NOTES:

All steps easy unless otherwise noted.

Screwdriver used is regular Phillips screwdriver unless noted. Used to remove all screws.

If no tool mentioned, operation done with hands.

Dissassembly Steps

1.Staple remover was removed by pressing on indentation with the symbol and pulling towards the back of the stapler

2.Black casing was removed by pinching at the front and sliding towards the back of the stapler (to completely remove, move to the back as far as it easily goes, then pinch the front of the piece and pull firmly until it comes off)

3.Sticker showing battery positioning was cut with a slot screwdriver

4.Stapler was turned over, and the black padding and white “Swingline” sticker were peeled off

5.Two screws on left hand side of casing was removed with screwdriver

6.Six screws on bottom of casing were removed wish screwdriver

7.Blue staple depth tabs were removed by pulling off

8.Casing was removed by carefully pulling each half (left and right) in opposite directions. Pulled until completely separated, but some slack still in wires

9.Battery contacts removed by sliding out of their slots

10.Screws holding circuit on left side of casing removed with screwdriver

11.Blue manual-auto switch pulled out

12.Manual trigger removed by pulling off support pegs (Needed slot screwdriver to pry trigger off of supports)

13.Casings completely removed and set aside

14.LED bulb removed

15.Two screws holding metal gear frame to bottom casing on left side removed with screwdriver

16.Two screws holding metal gear frame to bottom casing on bottom removed with screwdriver

17.Bottom casing removed and set aside

18.Black-and-red and red-and-white-and-black wires running from bottom casing disconnected from circuit board

19.Black-and-red wires running from lower front of stapler removed

20.Main circuit board screw removed

NOTE: single black wire pulled out of socket during next step, making complete reassembly impossible

21.Circuit board removed and wrapped around toward back of stapler

22.Screws holding metal gear casing and plastic gear casing removed

23.Slot screwdriver used to bend lock washer until it could be removed from the last gear shaft

24.Plastic and metal casings separated

25.Shaft at back and spring coil removed

26.Gear casing separated from staple slide

27.Screws holding plastic and metal bottom casings removed, and pieces separated

Part Table

Part #	Part Name	Quantity	Purpose	Material and Reason for Choice of Material	Manufacturing
1	Spring	1	Holds potential energy	Steel, Needs to be sturdy, but compressible	Extruded, Shaped
2	Shaft	12	Supports gears, aligns parts	Steel, Holds shape well under stress	Extruded
3	Washer	2	Provides spacing between fasteners and casings	Steel, Holds shape well	Cut
4	Lock washer	4	Holds shafts in place	Steel, Less likely to bend when pulled on	Cut
5	Casing	4	Shields insides from environment	ABS Plastic, Sturdy, weather resistant	Injection Molded
6	Foam Pad	2	Cuts down on noise, holds parts in place	Foam, Suppresses sound and movement	Cut
7	Battery Contacts	2	Transfers electrical energy from batteries	ABS Plastic, Steel, Needs to conduct electricity	Injection Molded, Cut
8	LED Light	1	Sends visual signals to user	ABS Plastic, Needs to be clear	Injection Molded
9	Manual Start Button	1	Can be pressed to eject staple	Plastic, Outside parts need to be weather resistant	Injection Molded
10	Staple Remover	1	Can be used to remove unwanted staples	Plastic, Steel, Holds shape well under stress	Injection Molded, Machined
11	Staple Tray	1	Stores staples until they are used	Steel, Staples need to slide easily	Machined
12	Staple Pusher	1	Ejects staple when pressure applied	Steel, Holds shape well under pressure	Machined
13	Steel Gear Casing	1	Holds gears in place	Steel, Can't deform during operation	Machined
14	Rivet	1	Holds Staple Pusher to frame	Steel, Holds shape under pressure	Cut
15	Gears	6	Transfers kinetic energy from motor to Staple Pusher, changes power of system	Plastic, lightweight	Injection Molding
16	Motor Frame	1	Encases motor	Steel, Keeps other parts out of motor	Machined
17	Plastic Gear Casing	1	Helps hold gears in place	Plastic, Lightweight but sturdy	Metal Casting
18	Rubber Spacer	1	Provides spacing between fasteners and casings	Rubber, Has some elasticity	Cut
19	Drive Spacer	1	Helps hold gears in place	Plastic, Lightweight	Injection Molding
20	Electric Motor	1	Turns electrical energy to kinetic energy	Steel, Needs to conduct electricity	Machined
21	Staple Tray Button	1	Ejects staple tray	ABS Plastic, Outside parts need to be weather resistant	Manufactured
22	Frame for Button	1	Holds button in place	Steel, Needs to be held in place during operation	Metal Casting
23	Circuit Board	1	Organizes and interprets electrical signals	Silicon, Plastic, Conducts electricity well, won't interfere with circuits	Manufactured
24	Ribbon	1	Used to remove batteries	Nylon, Flexible and won't tear when pulled on	Manufactured
25	Metal Coil	1	Stores potential energy	Steel, Good elasticity and hold shape	Machined
26	Plastic Display	1	Houses LED light	ABS Plastic, Needs to be clear	Injection Molding
27	Small Circuit Board	1	Organizes and interprets electrical signals	Plastic, Silicon, Conducts electricity well, won't interfere with circuits	Manufactured
28	Plastic Slide	1	Adjusts how far down from top of paper staple will be inserted	ABS Plastic, Outside pieces need to be weather resistant	Injection Molding
29	Plastic Housing	2	Protects inside pieces	ABS Plastic, Outside pieces need to be weather resistant	Injection Molding
30	Screws	25	holds separate pieces together	Steel, Holds shape well under stress	Machined
31	Plastic Ends	2	Used with Plastic Slide	ABS Plastic, Outside pieces need to be weather resistant	Injection Molding
32	Rubber Bottom	1	Provides cushion between stapler and surface	Rubber, Won't scratch tabletop	Cut
33	Information Sheet	1	Contains Model Name and other info about stapler	Aluminum, Plastic Coated, Can be printed on easily	Manufactured
34	Small Plastic Housing	1	Protects inside pieces	Plastic, Outside pieces need to be weather resistant	Injection Molding
35	Wires	6	Transfers electrical signals to different parts of stapler	Copper, Rubber, Conducts electricity well, insulates well	Manufactured

Pictures Of Dissection

Before Dissection

After Step 8

After Step 13

After Step 19

After Disassembly

Suggested Changes

We suggest the following changes be made to the product:

• Make wires more secure

We felt the inside workings of the stapler were too delicate. Many of the wires running from the main circuit board to the various parts of the stapler were not attached securely enough. The wires were very thin and could easily be cut or pulled out of their connections if not handled with extreme care. If heavier adhesives or thicker wires were used, this would be less of a problem.

• Change staple tray

The staple tray is easily jammed. It is supported on two rails, one on each side of the tray. When the button is pressed to eject the tray so staples can be loaded, the tray usually gets caught up on its rails. The user then needs to pull on the tray to create enough clearance to load the staples into the tray, and the force needed is usually significant. We suggest polishing the rails and the tray, or using a lubricant, in order to decrease the friction between the rails and the tray and prevent the jamming. The rails and the tray could be manufactured so that the fit between them is more exact, which could also help prevent jamming. If the fit is too loose, there could be too much play between the parts, allowing them to jam, which seems to be the case now. If the fit is too tight, however, the friction between the parts increases, which could also cause it to jam.

• Increase clearance where paper is inserted

Due to the rigidity of the stapler's casing, there is little clearance where the paper is inserted. This prevents the user from stapling large documents. Increasing this clearance would allow more papers to be stapled at once, although it would increase the overall size of the stapler. Also, a stronger motor or different gear ratios might be needed to ensure the stapler has the power to force the staple through a thicker stack of papers.

Assembly

The assembly procedure is very much as the reversed process of disassembly procedure, and is done mostly by hand, screwdrivers only in use when screws are used to attach components:

1.Put gears back into gear casing

2.Shaft at back is put back with the metal casing by using the washer

3.Circuit board is attached back into the metal casing using 2 screws

Note: the single black wire that connect between the main circuit board and the motor is pulled out, we can’t fixed it due to lack of proper tools

4.The spring is now being attached back on

5.Black-red wires running from lower front of stapler attached

6.Black-red and red-white-black wires running from bottom casing are attached back to the main circuit board

7.Bottom casing is now being attached back to the whole metal casing using 4 screws, 2 on the left side, 2 on the right side

8.LED bulb attached back to the plastic casing

9.Blue manual-auto switch is now attached between the metal casing and the bottom plastic casing.

10.Battery contacts attached back to the main black casing

11.The 2 big black casing now being attached back to each other

12.The two big black casing now being attached back to the bottom plastic casing using 6 screws

13.Blue staple depth tabs are attached

14.The “Swingline” sticker now attached back to the bottom

15.The staple remover now attached back to its original slot

After Assembly

1. As stated in the executive summary, the principles behind the product’s operation are pretty simple. There are two mode of the operation: Manual and Auto (they can be alternated by using the auto-manual switch that locates on the left side of the stapler).

• In auto mode, when we insert the document into the staple slot, the document will touch a metal sensor which connected to a switch. This switch then will automatically move that subsequently close the circuit within the mother circuit board. The mother board now send signal to the motor, which triggers it to start turning its shaft. The motor’s shaft is connected to a set of gears, causing to spin, which move to staple to push down, staple the document.

• In Manual mode, we switch the auto-manual switch, which will disable the metal sensor. Now when we put the document into the staple slot, we have to push a trigger on top of the stapler. The trigger work exactly like the sensor’s switch in the auto mode. Everything else happens exactly the same as in the auto mode.

The product did not run the same as before due to a technical difficulty. The housing for the wire within the stapler was pretty fragile. During the disassembly process, we accidentally pull the black wire that connected the mother circuit board and the motor, therefore, the operation is erupted. We can’t fix this problem due to technically difficulty caused by lack of proper tools.

2. The most important part to research would be in the area of how many papers the stapler could staple. This number would have to be exact because it would most likely be used while advertising the product. The first step would be to determine how much power is needed to punch through a piece of paper; from there you can design a motor that matches the amount of power needed to staple the desired amount of papers. When this is done you can design the size of the staple to match the power of the motor. The motor may be able to punch through 40 papers but if the staple can not reach that far you can not say your staple will work on 40 papers.

3. The disassembly and assembly process is pretty much the reverse of one another. Some of the steps within the processes can be switch, but the general big steps are just the reverse of each other. Because it’s basic principles that you take some thing off, you just have to put the back the same way (e.g. you unscrew a screw on one slot by turning the screw counterclockwise, then when you put it back, you will turn the screw clockwise). We use the same set of tools to assemble and disassemble the product. We were not able to assemble of the product due to lack of proper tools ( to fix the black wire that connects the mother circuit board and the motor)

4. It is stated in the executive summary that we want to make these changes:

• Better housing of the wire. The wire connecting to the motor should be held in place by a clamp. Other exposed wires should be held in place by tape so that they are not loose and easily pulled.

• Better design for the stapler slide to avoid jamming. If the release button was able to push down farther it wouldn’t catch the staple tray causing it to stop short of being fully extended. Also if the spring used had more resistance it would provide a stronger force when ejecting the staple tray.

• The outer casing should be altered so that it does not cover the staple tray. This would give the consumer easy access to the tray so that he/she can see why the tray is jammed.

• The clearance of the stapler should be raised so it can staple bigger documents, which means the addition of a stronger motor.

• The design uses 5 gears. If this number was reduced to three gears more space would be available for a larger motor. This would also reduce the amount of energy lost due to friction between the gears, which makes better use of the motors power.

• As for the design, we want to see more stable design. The material that is used to cover the outside is very fragile. Since it is a portable device, it is inevitable that user may drop the product. The plastic cover was indeed very brittle, so it would break very easily.