Snow blower
Encyclopedia
Snow
Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...
from an area where it is not wanted, such as a driveway
Driveway
A driveway is a type of private road for local access to one or a small group of structures, and is owned and maintained by an individual or group....
, sidewalk
Sidewalk
A sidewalk, or pavement, footpath, footway, and sometimes platform, is a path along the side of a road. A sidewalk may accommodate moderate changes in grade and is normally separated from the vehicular section by a curb...
, roadway, railroad track
Rail tracks
The track on a railway or railroad, also known as the permanent way, is the structure consisting of the rails, fasteners, sleepers and ballast , plus the underlying subgrade...
, rink
Rink
Rink may refer to:* Ice rink, used for ice skating* Ice hockey rink*Curling rink, used to refer to both a curling team and the playing surface*a roller rink, used for roller skating or roller hockey...
, runway
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...
, or houses. The term "snow thrower" is often used to encompass snow throwers and snow blowers, however, in proper a snow thrower is a machine that uses a single stage to remove or "throw" snow while a snowblower uses two stages to remove or "blow" snow. It can use either electric power
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...
, or a gasoline or diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
to throw snow to another location or into a truck to be hauled away. This is in contrast with the action of snow plows, which push snow to the front or side (shovel
Shovel
A shovel is a tool for digging, lifting, and moving bulk materials, such as soil, coal, gravel, snow, sand, or ore. Shovels are extremely common tools that are used extensively in agriculture, construction, and gardening....
s can be similarly used).
Snow throwers range from the very small, capable of removing only a few inches (a few cm) of light snow in an 18 to 20 in (457.2 to 508 mm) path, to the very large, mounted onto heavy duty winter service vehicles and capable of moving 10 feet (3.05 m) wide, or wider, swaths of heavy snow up to 6 feet (1.83 m) deep. Snow blowers can generally be divided into two classes: single stage and two stage.
Single-stage and two-stage snow throwers
Impeller
An impeller is a rotor inside a tube or conduit used to increase the pressure and flow of a fluid.- Impellers in pumps :...
to both move the snow into the machine and force it out the discharge chute. The impeller is usually in the form of two or more curved plastic paddles that move snow towards the centerline of the machine where the discharge chute is located. Single-stage snow throwers usually are light duty machines. Small electric machines can actually be picked up to chew away deep snow. Two-stage snow blowers range in power from a few horsepower to very large machines powered by diesel engines of over 1000 horsepower (746 kW). The large machines are used for clearing roadways and airport runways. These are capable of removing large
amounts of snow quickly. Some municipalities use larger snow blowers to clear snow from streets after a snowfall, often by throwing the snow into trucks which haul it away.
Two-stage machines for home use are usually self-propelled, using either large wheels equipped with tire chains or, in some cases, tracks. The term "two-stage" means that there are two mechanisms used to move the snow. The first is the auger and the second is the impeller. The auger feeds the snow to the high-speed impeller where the impeller blows the snow out of the machine. These are usually single-purpose machines, though some are detachable front ends that can be replaced with other implements, such as a rotary tiller.
The auger drive is usually equipped with a shear pin
Shear pin
A shear pin is a safety device designed to shear in the case of a mechanical overload, preventing other, more-expensive parts from being damaged...
. If a major jam occurs in the auger, this pin will break. This controlled failure prevents damage to the auger drive gears. Once the pin has failed, it must be replaced before the machine can be used again; this is generally a relatively simple process.
Safety issues
The U.S. Consumer Product Safety Commission estimates that each year there are approximately 5740 snowblower related injuries in the United States which require medical attention. One problem with the design of the snow blower is that snow can build up in the augerAuger
An auger is a drilling device, or drill bit, that usually includes a rotating helical screw blade called a "flighting" to act as a screw conveyor to remove the drilled out material...
, jamming it and stalling the motor. This is complicated by the fact that the auger could deform before applying enough resistance to the motor to turn it off. If the jam is cleared by hand, it is possible for the auger to return to its natural shape suddenly and with great force, possibly injure the user; snow blowers are a leading cause of traumatic hand and finger amputations. The correct procedure is to turn off the engine, disengage the clutch and then clear the jam with a broom handle or other long object.
Most modern machines mitigate this problem by including a safety system known as the "Dead man's switch
Dead man's switch
A dead man's switch is a switch that is automatically operated in case the human operator becomes incapacitated, such as through death or loss of consciousness....
" (which may be electrical as implied or mechanical in design, such as a lever
Lever
In physics, a lever is a rigid object that is used with an appropriate fulcrum or pivot point to either multiply the mechanical force that can be applied to another object or resistance force , or multiply the distance and speed at which the opposite end of the rigid object travels.This leverage...
), to prevent the mechanism from rotating when the operator is not at the controls. In some jurisdictions, this is mandatory requirement.
In December 2008, a snow blower accident made national headlines in the United States when Joe Sakic
Joe Sakic
Joseph Steven "Joe" Sakic is a former Canadian professional ice hockey player and current hockey executive. He played his entire National Hockey League career with the Quebec Nordiques/Colorado Avalanche franchise. In his 20-year tenure, Sakic won the Stanley Cup twice, captured numerous NHL...
, the famous captain of the Colorado Avalanche
Colorado Avalanche
The Colorado Avalanche are a professional ice hockey team based in Denver, Colorado, United States. They are members of the Northwest Division of the Western Conference of the National Hockey League . The Avalanche have won the Stanley Cup twice, in 1995–96 and 2000–01. The franchise...
hockey franchise of the National Hockey League, sustained three broken fingers and tendon damage when he attempted to clear the auger of his snowblower by hand. Sakic required surgery to repair his hand and reattach his fingers.
History
Dalhousie, New Brunswick
Dalhousie is a Canadian town located in Restigouche County, New Brunswick.- History :Dalhousie is the shire town of Restigouche County and dates European settlement to 1800. The Town of Dalhousie has been through some very distinct periods between its founding in 1825 and today...
patented a "Railway Screw Snow Excavator" in 1870. Various other innovations also occurred. However, it is Arthur Sicard (1876-1946) who is generally credited as the inventor of the first practical snow blower. In 1925 Sicard completed his first prototype, based on a concept he described in 1894. He founded Sicard Industries in Sainte-Thérèse, Quebec
Sainte-Thérèse, Quebec
Sainte-Thérèse is an off-island suburb northwest of Montreal, in southwestern Quebec, Canada, in the Regional County Municipality of Thérèse-de-Blainville....
and by 1927 his vehicles were in use removing snow from the roadways of the town of Outremont
Outremont (borough)
Outremont is a borough of the city of Montreal, Quebec, Canada. It consists entirely of the former city on the Island of Montreal in southwestern Quebec, Canada...
, now a borough of Montreal
Montreal
Montreal is a city in Canada. It is the largest city in the province of Quebec, the second-largest city in Canada and the seventh largest in North America...
. His company is now a division of SMI-Snowblast, Inc. of Watertown, New York.