Snow blower
A snow blower or snow thrower is a machine for removing snow from an area where it is not wanted, such as a driveway, sidewalk, roadway, railroad track, rink, runway, 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, or a gasoline or diesel engine 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 (shovels 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 to 508 mm) path, to the very large, mounted onto heavy duty winter service vehicles and capable of moving 10-foot (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.
Contents |
[edit] Single-stage and two-stage snow throwers
Single-stage snow throwers use a single high-speed impeller 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. 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.
[edit] 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.[1] One problem with the design of the snow blower is that snow can build up in the auger, 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.[2] 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" (which may be electrical as implied or mechanical in design, such as a lever), 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, the famous captain of the Colorado Avalanche 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. The team denied reports that Sakic required surgery to reattach one of his fingers. [3]
[edit] History
Robert Carr Harris of Dalhousie, New Brunswick patented a "Railway Screw Snow Excavator" in 1870. Various other innovations also occurred.[4] 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.[5] He founded Sicard Industries in Sainte-Thérèse, Quebec and by 1927 his vehicles were in use removing snow from the roadways of the town of Outremont, now a borough of Montreal. His company is now a division of SMI-Snowblast, Inc. of Watertown, New York.[6]
[edit] See also
[edit] References
[edit] External links
 |
Wikimedia Commons has media related to: Snow blowers |
- Vintage snowblowers
- Snowblower history
- Snow blower selection guide A guide on how to choose a snow blower or snow thrower
- snow blower reviews - understanding the different types of snow blowers
