1.0 1.0
Intr Introd oduc ucti tion on
A vacuum
cleaner is
a
device
that
uses
an
air pump to
create
a
partial vacuum partial vacuum to to suck up up dust and and dirt dirt,, usua usually lly from from floo floors, rs, and and opti option onal ally ly from from othe other r surfaces as well. The dirt is collected by either a dustbag or a cyclone for cyclone for later disposal. disposal. The vacuum vacuum cleaner cleaner evolve evolved d from from the carpet sweeper via via manual manual vacuum vacuum cleaners. cleaners. The first manual models, using bellows, came in the 1860s, and the first motoried models came in the beginning of the !0th century."a century."acuum cuum cleaners, which are used in homes as well as in industry, e#ist in a variety of sies and models which are small battery$operated hand$held devices, devices, domestic domestic central vacuum cleaners, cleaners, huge stationary industrial appliances that can handle handle several several hundre hundred d litres litres of dust dust before before being being emptie emptied, d, and self$pr self$prope opelled lled vacuum vacuum trucks for recovery of large spills or removal of contaminated soil. A vacuum%s suction is caused by a difference in air pressure. An electric fan reduces the pressure inside the machine. Atmospheric pressure then pushes the air through the carpet and into the nole, and so the dust is literally pushed into the bag. "acuums by their nature cause dust to become airborne, by e#hausting air that is not completely filtered. This can cause health problems since the operator ends up inhaling this dust. There are s everal methods manufacturers are using to solve this problem. &ome methods may be combined together in a single vacuum. Typically the filter is positioned so that the incoming air passes through it before it reaches the motor. Typically, Typically, the filtered air then passes through the motor for cooling cooling purposes. purposes. 'ost vacuum cleaners are supplied supplied with various various specialied specialied attachments, attachments, such as tools, brushes and e#tension wands, which allow them to reach otherwise inaccessible places or to be used for cleaning a variety of surfaces. The most common of these tools are hard floor brush ,powered floor nole, dusting brush ,crevice tool, and upholstery nole.
2.0
Manufacturing Process and Technology Employed
Plastic parts
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1 'any of a vacuum cleaner%s plastic parts begin with computeried drafting and design systems ()A**+. The parts are shaped in a two$part steel mold, called a die that is lowered into the chamber of an inection$molding machine.
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! Tiny plastic pellets stored in a large hopper ne#t to the machine are poured into a
An example of a canister-type vacuum cleaner.
heating vat and melted. The pellets are either purchased in the color desired or colored with pigments as they are melted. •
- The melted plastic, inected under high heat and pressure into the chamber of the inection molding machine, penetrates every part of the mold. The two halves of the mold open enough to let the plastic part fall into a bin. Although the pieces are still hot to the touch, the plastic hardens on contact with the air as the tool opens. The plastic pieces are stored in bins that can be rolled to the assembly line as needed.
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'any identical plastic parts of the same type are made during the inection process. /hen the desired number have been made, the tool is removed from the inection molding machine, another one is inserted, and the process repeats as supplies of another part are formed.
The assembly line •
"acuum cleaners are manufactured in an assembly$line process, with workers at assembly stations attaching subassemblies or individual parts to the vacuum as it moves along the line. Assembling an upright vacuum starts with the base, which is made of metal or molded plastic. The steel beater bar with brushes fitted into (a subassembly+ is then pulled from a bin and inserted into fitted notches at the front of the base. The beater bar has a locknut on one end and a cap on the other so the owner can open it and replace the brushes when necessary. A rubber drive belt is placed in a guide channel around the beater bar and pulled over a belt guide and motor pulley on the underside of the base.
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6 A steel base plate is fitted into notches in the front of the base and latched into place with a cam lock (a turning lever+ over the underside of the belt and pulley. The steel base plate is a subassembly that has small rollers on it and openings near its front where the beater bar and brushes will agitate the carpet (to release dirt+ during operation.
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At the rear of the base, an a#le is inserted through a tunnel$like opening that passes from one side of the base to the other. A release handle is fitted onto one end of the a#le2 it is a simple locking lever that allows the vacuum%s operator to lower the handle during operation or raise and lock it into place for storage. /heels are added to both ends of the a#le and are locked into place.
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8 The fan is bolted onto the base, and the motor assembly is attached to the top side of the base. The electrical connections from the motor to the fan and light, and from the motor to the electrical cord connection are made. A lightbulb is installed in a socket in the front of the base. A plastic housing that forms the top of the vacuum cleaner and fully encloses the motor and fan is snapped into place. 3t has already had a rubberied
bumper wrapped around its sides and front. 3t also carries a clear plastic panel allowing the light bulb inside to shine through as a 4headlight.4 •
5 lastic fittings that support the bag and handle are attached to the rear of the base. An opening at the back of the base holds a rubberied length of fle#ible hose that transfers dust from the fan to the bag2 this hose is fastened to the base opening and to the plastic fitting leading into the bag support. At the top end of the handle, a plastic unit that holds the top end of the bag is bolted through the handle. 7e#t, electrical connections inside the handle are completed, and the electrical cord that has been attached to the back of the base is tied to the connections within the handle, allowing the machine%s operation to be controlled by a switch near the top of the handle. The length of electrical cord leading from the machine to a power outlet is connected. or packing and shipping, this cord is looped and tied with a twist tie2 the owner will wrap it around storage supports on the handle.
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6 The final touches are added, including attaching the bag, the inner disposable bag, and outer markings (preprinted on decals that list the manufacturer, operating instructions, and information such as the serial number and the power of the motor+.
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10 The completed machine is taken to packing department where it is wrapped in a plastic bag and put in a carton. A bo# of plastic attachments, including noles and a hose for upholstery cleaning, is also put in the carton with an information booklet, assembly instructions, and a warranty card. The cartons, which have been preprinted with marketing information, are then closed, sealed, and stored for shipping and distribution.
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!esign "oncept #$A$E and %uality assurance
ortable vacuum cleaners are made in many general configurations, providing a range of cleaning actions to meet a broad range of customer re9uirements. The canister type has a cylindrical body containing the motor, fan, and other operating parts, and a removable, disposable paper dust bag. The canister is pulled over the floor on a set of wheels. The upright model is a push$pull device also mounted on wheels2 the motor is mounted in a housing over the fan, beater bar and brushes, and drive belt. An upright handle, e#tending vertically from the back of the machine, carries both the electrical power cord and brackets to hold the dust bag or plastic dust canister. A simple locking device on the rear of the motor unit allows the handle to be lowered so the operator can maneuver it under tables and around other furniture. "acuum cleaner design used to focus e#clusively on cleaning effectiveness, ease of operation, and low noise level. &ince about 1550, however, almost all maor manufacturers have also produced lines to reduce dust and allergens during vacuuming. These units usually have removable plastic canisters to contain the dust and are less to let fine particles escape through the bags and back into the air. 'any are also e9uipped with replaceable filters for very fine particles. The partial vacuum produced by the fan has been improved, with more powerful motors and fans that still operate 9uietly. anasonic%s models feature a bypass motor that pulls dirt directly into the bag preventing wobble of the fan and possible motor burnout. These models also have onboard attachments2 the suction can be transferred directly to the attachments. :ighter materials and a lighter total weight for these units compensate for the weight of the attachments. &.0
'eferences i+ http;<cleaner iii+ http;<matchlock
