Abstract:
A high efficiency snow thrower relying on a cutting action to create snow chunks which are conveyed and discharged, using one or more cutter bar arrays arranged in the front opening of a housing and an auger member which also has a cutting edge on helically wound strips splitting the packed snow and conveying chunks of the same while importing significant velocity to an impeller pocket at the center of the helical strip, which discharges snow chunks out through a discharge chute.

Description:
BACKGROUND OF THE INVENTION 
     This invention concerns machines which remove deep snow from roadways, driveways, etc. by conveying the snow to an impeller which throws the snow some distance from the machine, either to be collected for transport or into a pile some distance from the roadway. 
     A common arrangement is the combination of a rotating auger-screw conveyor the front of the machine which feeds snow into a separate central impeller. 
     This arrangement consumes considerable power since it pulverizes the snow, grinding it into a powder. The auger is also used to break up packed snow, which it does but quite-inefficiently as it utilizes a scraping action to accomplish this. 
     The impeller also consumes considerable power in throwing the snow in the finely powered condition in which it is received by the impeller from the auger. 
     These inefficiencies require high horsepower engines, which result in heavy and costly machines. 
     It is the object of the present invention to provide a combination of elements which efficiently breaks up the snow and propels the same away in such a manner that only a considerably reduced horsepower is required for a given application. 
     SUMMARY OF THE INVENTION 
     The above recited object and others which will become apparent upon a reading of the following specification and claims are achieved by providing an arrangement of elements which act primarily to cut up by splitting the compacted snow or other material rather than to break up the snow by the grinding and scraping action heretofore relied on. 
     Specifically, one or more arrays of rotating cutter assemblies (bars are shown in this example) are located just forward of a rotating auger-cutter member. The cutters comprise a series of bars each having a blade end extending generally axially but angled slightly to create a slicing and pulling action when driven by the rotation of a mounting shaft. 
     The auger-cutter member includes a rotating cylindrical shaft or tubular mounting extending on an axis that will contribute to the desired action and to the rear of the cutter bar shaft, a pair of opposite helically wound conveying strip segments projecting from the surface of the auger. An axially extending cutter edge is formed along each radial strip, angled slightly to create a slicing, gathering action and confining the cut material to effectively impart kinetic energy to the conveyed chunks of material to assist in the throwing action. 
     The oppositely helically wound strip segments meet at the auger center where an impeller pocket is formed by the joined strip ends. 
     A wedge shaped shield deflector is disposed forward of the center where the impeller pocket is located to move the material to the sides and into the adjacent cutter bars and auger cutter strips for cutting and conveyance to the impeller pocket. 
     The packed material is efficiently cut into chunks rather than being pulverized by the cutter arms and auger edge. The cut up material is conveyed into the impeller pocket at sufficient velocity as to contribute to the throwing action imparted by the impeller itself. 
    
    
     DESCRIPTION OF THE DRAWING FIGURES 
     FIG. 1 is a front perspective view of a high efficiency snow thrower according to the present invention. 
     FIG. 1A is an enlarged perspective view of an end portion of a cutting bar incorporated in the snow thrower shown in FIG.  1 . 
     FIG. 1B is an end view of the cutting bar end view shown in FIG.  1 A. 
     FIG. 2 is an end view of the snow thrower shown in FIG.  1 . 
     FIG. 3 is a rear perspective view of the snow thrower shown in FIGS. 1 and 2. 
     FIG. 4 is a fragmentary perspective view of one end of the auger member and adjacent housing portions included in the snow thrower shown in FIGS. 1-3. 
     FIG. 5 is a fragmentary front view of a portion of the auger shown in FIG. 4 with the conveying strip and cutter edge. 
     FIG. 6 is an enlarged perspective view of a deflector shield structure included in the snow thrower of FIGS. 1-3. 
     FIG. 7 is an enlarged sectional view taken through the bottom of the auger-cutter and a fragmentary portion of the auger housing. 
     FIG. 8 is a fragmentary view of a snow thrower having two cutter bar arrays. 
     FIG. 9 is a front perspective view of another embodiment of the snow thrower having four stacked cutter bar arrays and two stacked auger conveyor cutter members. 
     FIG. 10 is a perspective view of a simplified snow thrower according to the present invention showing a snow shovel application. 
     FIG. 11 is a perspective view of a self propelled walk behind application of the snow thrower according to the present invention. 
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, certain specific terminology will be employed for the sake of clarity and a particular embodiment described in accordance with the requirements of 35 USC 112, but it is to be understood that the same is not intended to be limiting and should not be so construed inasmuch as the invention is capable of taking many forms and variations within the scope of the appended claims. 
     Referring to the drawings and particularly FIGS. 1-7, a snow thrower  10  according to the present invention is shown which includes an outer sheet metal housing  12 , open at the front with an upwardly angled top  14  defining input advanced against the piled snow. 
     The housing  12  is supported with an adjustable height skid plate  16  at each end and a center skid plate  18  attached to a centrally locator deflector piece  20  mounted to extend across the opening at the front of the housing. 
     An array of cutter bars  22  radially extend generally outwardly from a shaft  24  rotatably mounted extending horizontally across the lower region of the front opening of the housing  12 . 
     An auger member  26  is mounted recessed within the housing  12  to be rotatable about an axis parallel to the cutter bar shaft  24 . Other orientations of the auger member  26  are possible as long as the cutting conveying action is achieved. 
     The cutter bar shaft  24  and auger member  26  are both rotated by a drive unit  28  (FIG. 3) powered either by an engine  30  mounted on the housing top  14  or a power take off shaft  32 , right angle drive  34  and cross shaft  36 . Other suitable means for powering these components may be used. 
     The snow thrower  10  shown is suitable for a tractor mount using bracket  38 , and a suitable connection to the PTO (not shown) is made to shaft  32 . An auger tube  40  open at the front partially encloses the auger member  26 . 
     The improved snow thrower efficiency is achieved by the unique configuration and action of the auger member  26 , and also by that of the cutter bar array for heavier capacity snow throwers. 
     Specifically, the auger member  26  has features which cut the snow into chunks, and convey the same axially in such a way as to impart substantial kinetic energy to the cut chunks, significantly contributing to an impelling action produced by a pocket formed at the center of the auger member  28 , forcefully directing the conveyed chunks through an outlet chute  42  mounted over the center of the housing top  14 . The chute  42  is rotatable with a swingable baffle  44  allowing control over the direction of the stream of snow exiting the chute  42 . 
     The auger member  26  in this example includes a cylindrical mounting comprised of a hollow tube  46  rotatable on the bearings  48  supported on the respective housing sidewalls  50 . A conveying strip  52  projects from the tube  46  and has opposite segments wound helically in from each end in an opposite handedness to convey snow towards the center. The conveyance in this unit is toward the center, but other arrangements can be utilized. 
     A cutter-confinement edge  54  is formed along the length the strip  52 , extending axially towards the center. 
     The cutter edge  54  is angled outwardly slightly as shown in FIG. 5 to create a slicing, gathering action in splitting packed snow and to create a slinging action when conveying the snow. 
     It is important that the edge  54  rotates in close proximity to the auger tube  40  (FIG. 7) without creating any wedging action tending to jam the snow, to minimize grinding of the snow. 
     A wear plate  56  is welded to the bottom of the auger tube  40 . 
     The oppositely wound segments of the auger strip  52  meet at the center of the machine where they form an impeller pocket  60  (FIG. 4) which extends out to impart a throwing action, directing the cut up snow into the chute  42  located directly over the impeller pocket  60 . 
     The cutter bars  22  also each have an angled end  56 , inclined at an angle a 1  from the axial direction and tilted radially out at an angle a 2  (FIG. 1A) from the circumferential direction. This geometry creates a splitting, wedging, and gathering action as the edges of the ends  56  penetrate the packed snow, cutting the snow into chunks with a minimal energy expenditure. 
     The cut up snow chunks are passed into the auger member  26 , where further cutting occurs as described above, and the chunks are conveyed to the impeller pocket. The auger member  26  is rotated at relatively high speed, i.e., on the order of 200 rpm in order to function as an impeller conveyor. 
     The deflector shield  20  is located forwardly of the impeller pocket  60  to divert the snow to the adjacent portions of the conveyor strip  52  to prevent the impeller pocket  60  from expending energy simply slapping at the snow (FIG.  6 ). 
     The deflector shield  20  is formed of sheet metal, with a wedge shaped front piece attached to a rear section formed with a radiused face  62  receiving the auger member  26  and impeller pocket  60 . 
     A second array of cutter bars  22  may be provided on a second shaft  64  extending parallel and above the first bar  24  to improve performance in deeper snow packs, as shown in FIG.  8 . 
     FIG. 9 shows a heavy duty version  66  suitable for mounting to road clearing trucks, in which a much larger housing  68  mounts four stacked cutter bar shafts  70  arranged within the open front of the housing  68 . 
     Two stacked auger members  72  are rotatably mounted in the housing  68 , located behind multiple cutter bar arrays. 
     A larger chute  74  receives the larger volume of snow chunks. 
     FIG. 10 shows a much smaller shovel version of the snow thrower  80 , which consists of a single smaller auger member  82  in a smaller housing  84  attached to a long handle  86 . The cutter bar array is not included. The auger member  82  may be directly powered with an electric motor and extension cord (not shown). 
     Finally, FIG. 11 shows a self propelled walk behind version  88 , in which wheels  90  support the housing  92 , an engine  94  powering the wheels  90  as well as a cutter bar shaft  96  and auger member  98  rotatable in the housing  92  as in the above described embodiments. 
     A pair of outwardly angled handles  100  allow steering control in a well known fashion. 
     It will be appreciated that a high efficiency is achieved by minimizing the energy expended in comminuting the snow, instead cutting the snow into small enough chunks to create a flowable mass, and devoting most of the energy expended on imparting kinetic energy to this mass. The larger particle sizes are able to be thrown more effectively than a fine powder of snow. 
     It should be understood that the efficiency of operation allows the use of the machines on materials other than snow, i.e., soil, sand, etc.