Field

This invention relates to a manual snow plough.

Background

Snow removal equipment falls into two main categories: manual equipment, such as synthetic plastics and aluminium snow shovels and snow pushers; and motorised equipment such as powered snow ploughs and snow blowers.

Current manual snow removal equipment is low cost but, is insufficiently robust to effectively remove compacted snow. Additionally shovels can require significant effort subjecting a user to bending, twisting or lifting effort which can give rise to muscle strain and injury.

In addition a user or operator may slip on untreated surfaces in an effort to gain purchase so as to be able to dig into and shift loads of snow. Motorised snow removal equipment allows for the removal of compacted snow and requires minimal effort from the operator but is prohibitively expensive for many users and can be of limited use in confined areas. Added to this there is the problem of noise levels and the cost of fuel to run such motorised equipment. An object of the present invention is to overcome the aforementioned problems.

Another object of the present invention is to provide an improved manually operated snow plough that is easy to use and cheap to make. Another object is to provide a lightweight and compact device that is easy to deploy and occupies minimum space when stowed. Summary of the Invention

According to a first aspect of the invention there is provided a manual snow plough comprising at least one handle connected to a plough blade.

The invention thus permits a human user to operate the plough in confined areas to assist in the removal of loose and compacted snow deposits by optimising and concentrating an applied force by the user, without imposing excessive bending, lifting and twisting stresses on the user.

Ideally the plough blade is supported on a main frame which houses wheels.

A chipper blade is ideally located in front of the plough blade or attached thereto. The snow plough preferably comprises a symmetrical V-shaped plough head. The plough blade is preferably symmetrical and V shaped to displace loosened snow to both sides of the plough head simultaneously, thereby minimising any twisting moment being applied to the plough head by uneven distribution of the weight of loosened snow.

The chipper blade is preferably formed from hardened steel and is adapted to cut through frozen layers of snow and ice. It is ideally removable and replaceable and may be sharpened with a whetstone or file. The chipper blade may abut the leading edge of the snow plough. Alternatively there may be a gap between the chipper blade and snow plough leading edge. In a further alternative a sacrificial (not shown) sheath or a protective guard may overlay the leading edge of the snow plough so as to prevent damage thereto, for example from ice chips, grit or stones passing the past the chipper blade and under snow plough. One or more wheels, rollers or caterpillar tracks or other guides are located on an under side of the of the main frame of the plough, ideally around a central region. Additional wheels or rollers may be provided at a rearward region of the main frame. A footplate, with roughened, textured or anti-slip tread is located at a rearward face of the snow plough and provides a surface on which a user may place a foot and apply a forward thrusting force to urge the snow plough in a direction into a snow drift to be cleared.

The plough blade is preferably made of steel, alloy or a rigid reinforced synthetic plastics material, such as acrylonitrile butadiene styrene (ABS).

Ideally the angle of the V shaped profile of the plough blade is between 40° and 140° so as to provide an optimum angle of attack.

The chipper blade is preferably configured to provide the optimum clearance angle ideally between 0° and 20°; rake angle ideally between 0° and 45°and angle of attack (between 40° and 140°) for cutting and loosening compacted snow with minimum required human effort.

The chipper blade is preferably symmetrical and V shaped to match the "V" shaped profile and angle of attack of the plough blade and so as to shroud the plough blade. Advantageously the chipper blade is preferably made of steel, stainless steel and ideally has a hardened leading edge. The chipper blade is preferably positioned, in use, ahead of the leading edge of the plough head at ground level.

One set of wheels is preferably positioned toward the rear of the plough head such that effort applied via the handle(s) or foot plate is concentrated in front of the rear wheels, through the main frame to the chipper blade.

One spring-loaded set of ideally two wheels is preferably positioned toward the front of the plough head such that compression springs that act as shock absorbers, maintain the chipper blade clear of the ground. When force is applied via the handle(s) and/or foot plate, it is concentrated behind the front wheels and acts to compress the springs and lower the chipper blade to ground level. The force is therefore transferred through the handle and main frame to the chipper blade. This ensures that effort applied to the andle(s) and/or foot plate tends to maintain all the wheels/tracks in contact with the ground and brings the chipper blade down to the ground level whilst transferring most of the applied effort to the chipper blade for optimised snow cutting.

The main frame is preferably made of steel or aluminium alloy and is preferably configured to efficiently transfer effort applied to the handle(s) and/or to the footplate to the chipper blade with a high efficiency.

The main frame is preferably configured to provide a framework for attachment of components including: the chipper blade, wheel/track assemblies, plough blade and handle(s). All the aforesaid components are demountable, so that that the plough can be disassembled for storage or specific components may be replaced if worn or damaged.

The footplate preferably forms part of the main frame and is positioned such that effort applied to it, rearward of the point of contact of the wheels/tracks with the ground, compresses the front wheel assembly springs and is transferred via the main frame to the chipper blade. This ensures that effort applied to the foot plate tends to maintain all four wheels in contact with the ground and lowers the chipper blade toward the ground and maintains the chipper blade position relative to the ground whilst transferring most of the applied effort to the chipper blade for optimised snow cutting.

The footplate is preferably made of steel or stainless steel and ideally has a non-slip surface layer and/or corrugated profile.

The handle(s) are preferably made of tubular steel or aluminium alloy. The handle(s) are preferably attached to the main frame such that effort applied to the handle(s) acts to maintain all wheels/tracks in contact with the ground, causing forward motion of the snow plough and transfers effort via the main frame to the chipper blade. The handle(s) are preferably attached to the main frame by pivot arrangements to ensure that, whilst pushing or pulling the snow plough, no turning moment is applied to the plough head about the wheel axes that could cause the position of the chipper blade relative to the ground to change. The handle(s) pivoting arrangements preferably incorporate physical stops to limit allowed travel of the handle(s) about the pivot axis.

The handle(s) are preferably configured to enable operation of the plough from a standing position.

Advantageously the handle(s) are dimensioned and arranged so as to include comfortable hand grip(s) that allow the handle(s) to be grasped in differing ways whilst maintaining lines of force of any applied effort directly along the axis of the handle(s) to the main frame. This improves the efficiency of the plough as- a machine.

The handle(s) preferably may include a means of adjusting length to suit operators of differing heights/arms lengths. A preferred embodiment of the invention will now be described, by way of example only, and with reference to the Figures in which:

Brief Description of the Figures

Figure 1 shows the general arrangement of the snow plough (side view); Figure 2 shows the general arrangement of the snow plough (isometric view); Figure 3 shows an exploded view of snow plough assemblies and components; Figure 4 shows detail of a front wheel assembly spring assembly; Figure 5 shows the main frame with integral foot plate; Figure 6 shows the chipper blade; Figure 7 shows the plough blade; Figure 8 shows the handle(s) assembly;

Figure 9 shows a handle(s) assembly length adjustment arrangement;

Figure 10 shows a handle(s) assembly attachment pivot arrangement;

Figure 11 shows the angles associated with the chipper blade;

Figure 12 shows how the snow plough may be operated to loosen compacted snow;

Figure 13 shows examples of the different ways in which the handle may be gripped; and

Figure 14 shows examples of alternative handle arrangements.

Detailed Description of Preferred Embodiment of the Invention

Attention is first drawn to Figure 1 and Figure 2, showing one embodiment of a snow plough 100 according to the present invention.

Attention is also drawn to Figure 3, showing an exploded view of the snow plough 100 and illustrating key features and components. Figure 5 shows main frame 10 to which components are connected and depicts lateral side faces 70 and 72, strengthening bar 74, central brace 1 0 and a chipper blade support 300. Figure 6 shows a detailed view of chipper blade 30. Components of the main frame 0 may be welded or bolted together or cast as a single unit.

Figure 7 shows a detailed view of plough blade 20. Main frame 10 comprises rigid walls formed form sheet plastics, wood or metal, such as aluminium or steel. The frame acts a core of the snow plough 100 and is the component to which other assemblies and components are attached. In this sense the snow plough 100 can be disassembled for transport or long term storage.

Connected to the main frame 10, which is ideally in the form of a scoop with opposite facing side walls 10a and 10b are: a chipper blade 30 located at a . leading lower edge of the frame 10 and a plough blade 20 located adjacent to the chipper blade 30, a spring-loaded front wheel assembly 40, a rear wheel assembly 50 and a handle(s) assembly 60.

The fabricated rigid main frame 10 is of welded mild steel construction manufactured from mild steel plate and tube. In an alternative arrangement the main frame 10 could be of bolted, screwed or riveted construction. In an alternative arrangement the main frame could be fabricated from other suitable materials.

The fabricated rigid main frame 10 incorporates a foot plate 1. In an alternative arrangement the fabricated main frame 10 may be configured for rigid attachment of a separate foot plate .

The foot plate 11 is manufactured from steel plate and is attached to the main frame 10 by weld. In an alternative arrangement the foot plate 11 may be manufactured from an alternative suitable material. In an alternative arrangement the foot plate 11 may be attached to the main frame 10 by screws, bolts or rivets. The top surface of the foot plate 11 is profiled or treated to be non-slip with a suitable anti-slip coating, roughened surface and/or profiled array of studs/grooves.

The fabricated rigid main frame 10 is configured for rigid attachment of a chipper blade 30 and a plough blade 20. The fabricated rigid main frame 0 is also adapted to receive one or more handle(s) assembly 60 by means of pivot arrangements 61. The fabricated rigid main frame 10 is configured to receive two wheel assemblies 40 and 50. Each wheel assembly has one or two wheels.

The chipper blade 30 is attached to the main frame 10 by means of countersunk screws. In an alternative arrangement the chipper blade 30 may be attached to the main frame 10 by weld, bolts or rivets. However, it is ideally removable for sharpening or replacement.

Referring now to Figure 11 , showing chipper blade cutting angles. The chipper blade 30 is a single steel plate machined, formed and heat treated to provide a cutting edge with the required clearance angle, rake angle and angle of attack when the chipper blade 30 is rigidly mounted on the main frame 10. The chipper blade 30 is drilled and countersunk to allow attachment to the main frame 10 by means of countersunk machine screws. In an alternative arrangement the chipper blade 30 may be made from stainless steel. In an alternative arrangement the chipper blade 30 may be formed in multiple parts. In a further alternative arrangement the chipper blade 30 may be formed to allow attachment to the main frame 10 by weld, bolts or rivets. The plough blade 20 is a high-density plastic pressure die-casting. The plough blade 20 is positively located on elements of the main frame 10 and held in place by self- tapping screws. In an alternative arrangement the plough blade 20 may be made from steel or alloy or even wood. In an alternative arrangement the plough blade 20 may be formed in multiple parts. In an alternative arrangement the plough blade 20 may be attached to the main frame by weld, bolts or rivets.

The rear wheel assembly 50 comprises two wheels and an axle configured to be mounted toward the rear of the main frame 10. Attention is now also drawn to Figures 4 and 5, showing the arrangement of the spring sub-assemblies 41 to 44 of the front wheel assembly 40. The front wheel assembly 40 comprises two wheels, an axle 45 and two spring sub-assemblies 41 to 44. The wheels of the front wheel assembly 40 are allowed to spin freely on the axle 45. The axle 45 is supported by the spring sub-assembly bolt 43, through elongated holes in the main frame 10 at each end, said elongated holes sized and positioned to allow movement of the front wheel assembly 40 relative to the main frame 10. This ensures that at the full extent of movement, under the influence of the compression springs 42, the front of the main frame 10 and the chipper blade 30 are raised to a pre-set distance above ground level and at the full extent of movement, under the influence of effort applied to the handle(s) 60 and/or foot plate 11 , the front of the main frame 10 and the chipper blade 30 lowers to the optimum position relative to the ground for snow clearance.

A spring sub-assembly bolt 43 passes through a spring guide 41 , through an elongated hole in the main frame 10 and is screwed into the end of the axle 45 at each end. A compression spring 42 is fitted to the spring guide 43 and held in compression between the spring guide 43 and a spring holder 44 welded to the main frame 10.

Application of force to the handle(s) 60 and/or foot plate 1 compresses the front wheel assembly 40 sub-assemblies springs 42 allowing the front wheel assembly 40 sub-assemblies bolts 43 to move upward in the elongated holes in the main frame 10, due to the reactive force being applied by the ground, causing the front wheel assembly 40 to move upward in relation to the main frame 0 and chipper blade 30. The effect of this is to lower the front of the main frame 0 and the chipper blade 30 such that the chipper blade 30 optimum position relative to the ground for snow clearance is achieved. In an alternative arrangement the wheel assembly 40 spring sub-assemblies may comprise tension springs acting to pull the wheel assembly 40 down relative to the main frame 10.

Attention is now also drawn to Figures 8, 9 and 10 showing the handle(s) assembly 60, handle(s) assembly 60 length adjustment arrangements 62 and handle(s) assembly 60 pivot arrangement sub-assembly 61 respectively.

Attention is also drawn to Figure 3, showing different ways of gripping the handle(s) 60 and Figure 14, showing alternative handle(s) 60 arrangements. The handle(s) assembly 60 comprises a top handle section 67, fitted with a comfort grip 63, two lower handle tubes 68, each fitted with a pivot sub-assembly 61 , and two handle(s) assembly 60 length adjustment arrangements 62. In an alternative arrangement the handle(s) assembly 60 may comprise a single component with no length adjustment arrangement 62.

The top handle section 67 is formed from tubular mild steel and configured to allow the operator to grip the handle in different ways, as indicated in Figure 13, whilst ensuring that effort applied by the operator is directed down the left and right straight leg sections of the handle(s) assembly 60, as indicated by the arrows in Figure 3. Bends in the top handle section 67 further serve to damp some of the reactive shock load that exist in certain modes of operation, thus helping to protect the operator from fatigue and/or injury.

Lower extremities of the top handle section 67 down tubes are drilled or punched to accept the handle length adjustment arrangements 62. In an alternative arrangement the top handle section 67 may be formed from tubular alloy. In an alternative arrangement the top handle section 67 may take differing forms, examples of possible alternative forms are illustrated in Figure 14.

A tubular high density foam comfort grip 63 is fitted to the top handle section 67 as illustrated in Figure 8 to provide a comfortable grip area for the operator and insulate the operator from shock forces and the cold surface of the top handle section 67. Optionally shock absorbers may be built into the handles so as to absorb sudden impacts of hidden obstacles, such as stones, steps, walls or other objects that are covered in snow.

The lower handle tubes 68 are formed from tubular mild steel with the same internal and external diameter as the tube utilised to form the top handle section 67. The lower handle tubes 68 are reduced in diameter at one end for a proportion of their length adequate to provide the range of handle(s) 60 length adjustment required and to a diameter that would allow the reduced diameter section of the lower handle tubes 68 to slide freely in the internal diameter of the top handle section 67 open ends. The reduced diameter section of the lower handle tubes 68 are drilled or punched at fixed intervals to align with the holes in the lower extremities of the top handle section 67 down tubes and to accept the handle length adjustment arrangements 62 such that the overall length of the handle(s) assembly 60 can be adjusted by aligning different holes in the lower handle tubes 68 with the holes in the top handle section 67.

The handle(s) length adjustment arrangements 62 comprise the reduced diameter section of the lower handle tubes 68, the open ends of the top handle section 67 and bolts with profiled washers and star nuts sized to fit through the aligned holes in the lower handle tubes 68 and the top handle section 67. By aligning different holes in the lower handle tubes 68 with the holes in the top handle section 67 and fitting the bolts, profiled washers and star nuts different handle(s) 60 lengths can be achieved. In an alternative arrangement drop-nosed pins may replace the bolts, profiled washers and nuts.

At the non-reduced diameter end of the lower handle tubes 68 a pivot assemblies 61 are rigidly attached by means of swaging, pinning, bolting or riveting to enable attachment of the handle(s) assembly 60 to the main frame 10.

The pivot sub-assemblies 61 comprise a bushed pivot housing 65, a journal bolt and nut 66 and a travel stop plate 64. The travel stop plates 64 are rigidly mounted to the main frame 10 by means of setscrews. The bushed pivot housings 63 are rigidly connected to the lower end of the lower handle tubes 68 by means of swaging, pinning, bolting or riveting. The handle(s) assembly 60 is attached to the main frame by the journal bolts and nuts 66 secured through the bushed pivot housings 65 and mainframe 0 such that the lower handle tubes 68 are positioned between the two travel stops 80 and 82 on the travel stop plate 64, permitting pivoting of the handle through a°. The invention has been described by way of examples only and it will be appreciated that variation may be made to the above-mentioned embodiments without departing from the scope of invention. With respect to the above description then, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

For example a housing may be provided encasing the plough so as to prevent snow from clogging behind the plough blade. Handles and any cross pieces connecting tubes of handles, may be fitted with quick release connectors such as 'wing nuts'.

Wheels may be held on using 'quick-release' devices such as split pins or cotter pins, so as to enable them to be detached for stowage or replacement. .