A Technical Description Colin Porter ALG-TWR2000
General Description 1. General Description 1.1 Overview The Staples 3-Hole Punch is an office tool that creates 3 standard-sized holes in the margin of a sheet of paper. It uses a lever action to force down 3 circular blades into the paper placed inside of it. The holes that it creates are standard 6.35mm in diameter and are sufficient to support most standard binder rings. The hole positions can be adjusted to accommodate standard and non-standard spacings. A convenient collection tray is attached to the bottom of the hole punch to collect the chads (the scraps of paper punched out of the page). Figure 1 - Front View Figure 2 - Rear View Colin Porter 1
General Description 1.2 Operation A 3-hole punch is used primarily in homes and offices for self-printed documents. Printer paper generally contains no existing holes so the hole punch becomes necessary if the document is to be placed in a binder. The punch is very easy to operate. Along the front of the base of the punch is an opening (see Figure 3). A sheet of paper inserted into this opening will slide right in with no resistance until it hits the back bracket of the punching area. Typically, the left margin of the page is inserted facing up. However, the hole punch can accommodate any page orientation. Once in position the user simply needs to press down on the lever arm and the holes are effortlessly punched into the document. Figure 3 Page Insertion Area The hole punch itself is optimized for a standard 8.5 by 11 document but can accommodate both larger and smaller sizes. The page insertion area (the location on the base where the document rests waiting to be punched) is bordered along the back and left side by metal brackets. These brackets ensure that the document is in the standard position to create uniformly punched documents. As the document is fed into the insertion area it will hit the brackets and meet with resistance. This resistance tells the user that the document is in the proper position. The right side of the punching area does not have a bracket. This allows documents larger than 8.5 by 11 to be used (for example 8.5 by 14 legal size) as the extra length simply extends outside the insertion area. Figure 4 Document Before, Loaded and After Punching Colin Porter 2
2. 2.1 Body The body of the hole punch is comprised of 4 main components: Lever Arm Fulcrum Base Collection Tray Figure 5 Body Components 2.1.1 Lever arm The lever arm is 28cm long and 4-6cm wide (the width bulges in the middle). It is comprised of hard metal with a soft plastic partial-cover. The purpose of the lever arm is to receive the downward force of the user. It is attached to the base via the two fulcrum rivets. The plastic acts as a more comfortable material for the user to interact with but is otherwise not related to the punching mechanism. Colin Porter 3
2.1.2 Fulcrum The fulcrum is comprised of two metal rivets (one on each side of the hole punch) approximately 0.5cm in diameter. They attach the lever arm to the base of the hole punch and act as the pivot for the lever action. The head of the rivet on one side and a small metal band on the other side ensure a tight bond so that the lever arm and the base do not become separated. However, it is loose enough to still allow the lever arm to rotate around the rivet when pushed downward. Figure 6 Fulcrum Rivet 2.1.3 Base The base is the largest component of the hole punch. It is 28cm long by 6 cm wide. Two arched wings on either end rise up and are the attachment points for the fulcrum. In the middle of the base are two raised tabs of metal that run most of the length of the base. These raised tabs are where the guides are attached to the base. An oval shaped hole is cut into each of the tabs where the thumbscrews are inserted and screwed into the guides. 2.1.4 Collection Tray The collection tray is a soft plastic cover that is attached to the bottom of the base. Its purpose is to collect the chads (circular bits of paper that have been punched out). The tray fits snuggly around the entire bottom of the base but is soft and flexible so it is easily removed. Once removed, it makes disposing of the chads very simple. Figure 7 Collection Tray Exposed with Chads Colin Porter 4
2.2 Blade Apparatus The Blade Apparatus is the mechanism that creates the holes in the document. It is comprised of 4 main components: Guide Blade Spring Thumbscrew Figure 8 Blade Apparatus Components 2.2.1 Guide The guides are the metal housings for the springs and blades and ensure that the blades puncture the paper at a precise and pre-determined angle. They measure approximately 1.5cm long by 1.25cm wide by 1.25cm tall. They are rectangular in structure with a round opening on the top and bottom to allow the blade to move up and down. The spring is located entirely inside the guide while the blade is able to move from partially above to partially below. Colin Porter 5
2.2.2 Blade The blade is a cylindrical metal peg with the bottom end separated into two sharp triangular points. It is about 2cm high with a diameter of 6.35mm. The blade s purpose is to create the hole in the document when forced downward onto it. The sharp tips are to cut the paper when punching to ensure a clean cylindrical hole. 2.2.3 Spring The spring is a small metal coil located inside the guide and surrounds the main body of the blade. Small pegs on the side of the blade rest on top of the spring so that when the blade is pushed downward it compresses the spring (see Figure 9). The purpose of the spring is to provide resistance against the downward force of the user and to return the blade to an elevated position. By keeping the blade elevated a document can be easily inserted into the punching area. Figure 9 Spring in Compressed Position Colin Porter 6
2.2.4 Thumbscrew The thumbscrews are to fasten the guides securely to the base. When loosened, they allow the guides to slide along the metal tabs on the base to adjust the punching location. Figure 10 Thumbscrew Removed Colin Porter 7