Alligator Lopper: Gate4
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===Jaw Mechanism=== | ===Jaw Mechanism=== | ||
| − | '''Technical Name''': Reverse Motion Linkage | + | '''Technical Name''': Reverse Motion Linkage [[File:JawGears.gif|thumb|]] |
'''Components''': Gear, Jaw, Handles | '''Components''': Gear, Jaw, Handles | ||
Revision as of 19:36, 29 November 2012
Contents |
Gate Four
Product Reassembly
Assembly: Motor and Motor Mount
| Step Number | Step | Difficulty Rating | Image |
|---|---|---|---|
| 1 | Place the two parts of the motor together so that the coiled part fits within the magnet. |  | |
| 2 | Place the two sides of the motor cover together around the motor and secure in place with the screws. |  | |
| 3 | Use the wire retainer to hold the wires in place against the side of the motor cover. |  | |
| 4 | Take the large gear and place it in the motor mount housing so that its teeth interlock with the teeth of the drive shaft coming out of the motor. |  | |
| 5 | Place the large two hex bolts into the outlines of the bottom side of the motor mount cover. Fasten the motor mount cover to the motor mount, covering the large gear so that all that shows of it is its drive shaft. |  | |
| 6 | Fasten the motor mount cover to the motor mount using the philips and torque head screws. |
Assembly: Chain Guard and Chain Guard Cover
| Step Number | Step | Difficulty Rating | Image |
|---|---|---|---|
| 1 | Anchor the small black plastic clip into the inside of the outer cover so that its tension springs are anchored. |  | |
| 2 | Place the outer cover/handle cover over the bottom of the motor mount cover so that the two bolts imbedded in the motor mount extends through the cover. Make sure the black plastic clip is exposed on the outside of the cover and that the drive shaft of the large gear extends through the cover. |  | |
| 3 | Place the sprocket onto the drive shaft so that it sits on the outer cover. Place the chain bar underneath the black clip so that the two bolts extending through the cover pass through the slit in the bar. The black clip holds the bar against cover. |  | |
| 4 | Run the chain around the outside of the bar and sprocket so that if the sprocket is spun, the chain will also spin. |  | |
| 5 | Take the lower side of the moving jaw and |  | |
| 6 | Fasten the top half of the jaw to the bottom half of the jaw using the three philips head screws. |  | |
| 7 | Take the black Black and Decker cover and place it over the chain bar, sprocket, and chain bar. This seals off the chain saw components from outside debris. |  | |
| 8 | Secure the black cover to the outside cover using the two remaining nuts. They are fastened to the two bolts extending through the bar and both covers using the tool provided with the Alligator Lopper. |  |
Assembly: Outer Cover/Handles
| Step Number | Step | Difficulty Rating | Image |
|---|---|---|---|
| 1 | | ||
| 2 | | ||
| 3 | | ||
| 4 | | ||
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| 8 | |
Mechanisms
Drive Chain Mechanism
Technical Name: Gear train
Components:Sprocket, Large Gear and Chain
Purpose: The purpose of this mechanism is rotating the chain of the chainsaw.
How it works: The sprocket located on the shaft of the large gear spins simultaneously with rotation of the large gear. The teeth of the sprocket interlace with the chain to prevent slipping. When the gear increases the torque produced by the motor and transfers it to the sprocket, the chain begins rotate. As the sprocket is turned, it moves the chain by pulling a link towards it. Tension in the chain, which is circular, is being pulled towards the sprocket while the opposite side is being pulled away from the sprocket.
Switch Linkage
Jaw Mechanism
Technical Name: Reverse Motion Linkage
Components: Gear, Jaw, Handles
Purpose: The purpose of this mechanism enabling the user with the ability to open and close the mouth of the Alligator Lopper via the handles of the product.
How it works: The gear is held in place to the free moving aluminum jaw of the Lopper by a bolt and a lock nut. The teeth located on the handle, which provide rotation for that component, interlocks with the teeth of this gear. As user pulls the handles apart, the teeth of the handle rotates, which causes the turning of the gear. The gear that is attached to the jaw rotates and this causes jaw to rotationally open.
Design Revision
Portable Gasoline Power Plant
Increase Bar Size
Motor Assisted Opening Jaw
Description
This proposed design revision would completely alter both the trigger system and the jaw system. Instead of using two handles to manipulate the jaw into place around a branch, a small DC motor can be employed to do the same action as the user’s arms. Using such a motor would eliminate the need for two pivoting handles. As a result there would be one main handle extending out of the machine towards the user. A second horseshoe handle would be placed on the chain motor’s housing. A small secondary motor would be placed directly opposite the larger chain motor. This small motor would most likely contain a gear exchange to increase its torque. It would then drive a gear directly attached to the moving jaw, much like the current gear attached to the jaw on the product now. The motor would then be used to manipulate the jaw at the control of the user.
A new trigger system would thus need to be employed to insure a factor of safety is present in the product. The proposed trigger system would rely on two main triggers and two jaw control buttons. The trigger would be placed on the underside of the handle extending out of the product. It would most likely be surround by a trigger guard which would protect it from accidentally being depressed. On the opposite side of the handle from the trigger there would be two buttons: an open jaw button and a close jaw button. Pressing and holding either of these buttons would employ the motor into opening or closing the jaw. The orientation of the trigger and the jaw buttons allows the user to use his right hand to manipulate all three. When gripping the handle, the fingers would close around the trigger and squeezing the handle would depress it. The thumb of the right hand would then be able to use the two buttons controlling the jaw, much like how a user may interact with buttons on a TV remote. The second trigger would be placed on the horseshoe handle now attached to the chain motor housing.
Factors Governing the Design Revision
Global:
This design revision allows for less strenuous human interaction required to operate the product. By changing the jaw opening mechanism to a motor, more people which previously may have been limited in using the product by muscle limitations may now use the product. This semi-automation of the product makes it friendlier to woman and older homeowners, something which this product has strived to accomplish since its creation. Since this product is still intended for home owner usage and not commercial usage, its market does not change drastically when compared to the current product. This design revision only affects the different type of homeowners that can comfortably operate it.
Societal:
By changing the location of the handles along with the motor assisted jaw, the ergonomics of the product are improved in three major ways.
- The support handle is placed directly on the chain motor’s housing. This allows the user to more comfortably lift and support the product. The heaviest part of the Lopper is easily its motor which is used to spin the sprocket and chain. By placing a handle directly on this heavy component instead of having the user support it by handles located farther away from the motor, the user can more comfortably hold it. It essentially places a handle much closer to the product’s center of gravity making it easier to manipulate.
- By changing the jaw opening mechanism to motor control, the Lopper relies much less upon the user’s muscular force capacity. The current design requires the user to compress the handles with enough strength so that it forces the chain to cut the branch. This means the user must be able to exert this force for the length of time required by each cut. In addition to holding the product itself, this action can tire the user. The motor allows the user to use all of his strength to support and the position the product instead of dividing it between that and clamping the jaw. The lack of parts required to move by the user’s strength also allows the user to get a better grip on the Lopper. Since they are not closing or opening handles, their grip remains stationary on the product. This firm stationary grip gives the user more control when manipulating the product.
- The one trigger may be operated passively with the left hand and the other trigger and jaw control buttons may be operated by the right hand. The current product requires a squeezing action with both hands to operate the triggers. This design revision allows the user to engage the trigger on the handle located on the chain motor’s housing passively. Simply holding the product by this handle forces the trigger to be depressed against the user’s hand by gravity. This means only the right hand must squeeze the handle to engage the trigger. In addition the right thumb is used to operate the jaw instead of both arms and chest muscles. The actions required to open and close the jaw are minimal in comparison to the actions required by the current product.
In addition to improving ergonomics, the factor of safety already present in the current Lopper is increased with this design revision. Both triggers are left in place since this system for engaging the motor is effective. In addition to the triggers, the addition of jaw manipulation buttons forces the user to only manipulate the jaw when the product is plugged in. This decreases the chance that an awkwardly placed Lopper could spring open unintentionally exposing the chain. It also decreases the chance that the jaw could slip open in the middle of a cut since the motor controls the jaw, not the muscles of the user. Anything which takes the dependence of the product out of the muscular ability of the user and places instead in control of a motor increases the safety of the product.
Economic:
The price of the product would undoubtedly increase. An additional motor for the jaw system would cost somewhere between $5 to 15$, while the gears and housings would be about an additional $10 and the additional switches and wiring about another $5 to $10. Conservatively speaking, this design change would cost $35 dollars. At optimal costs, it could only cost an additional $20. Manufacturing costs would not change too much. The addition of the second motor and two new switches would be offset by eliminating a second major handle extending out of the product. Material requirements would not change radically since the new system can be built using the same materials as the rest of the Lopper.
Environmental:
Since the power system does not change on the Lopper, its emissions and impact on the environment does not change drastically. However since the system is less cumbersome to operate and easier to support, the amount of branches the user can cut from a stationary position increases. It is now easier to lift higher and cut branches at or above the user’s chest level. The operation of the product now depends on how far the user can comfortably support the product. The previous design relies on how comfortably the user can both hold the product and still be able to effectively provide force to operate the jaws. The design revision thus allows the user to operate the product farther from their body and also at a large height relative to the user’s chest. This means a large portion of the environment can be cut using the new Lopper. It is also more likely to be used in more awkward situations, like atop a ladder. This allows the user to trim higher branches and thick shrubs since the product is easier to manipulate.
