A dual blade wide-format rear-collection lawn mower including: a chassis, an engine mounted on an upper side of a rear portion of the chassis, and a grass cutter mounted on a lower side of a front portion of the chassis, the grass cutter includes a big grass cutter and a small grass cutter which are tangential to, and connected with, each other, a grass discharging channel is positioned at the side where the big grass cutter is located, and an entrance of the grass discharging channel is connected in a smooth transition manner with an out wall of the big cutter which is away from the small cutter, the grass discharging channel is tilted upward and backward and a grass discharging outlet thereof is connected with a grass collecting basket.

FIELD OF THE INVENTION

The present invention relates to a lawn mower, and more specifically, to a dual blade wide-format rear-collection lawn mower, which can be classified as a garden machine.

BACKGROUND OF THE INVENTION

With the requirements for city greening, lawn coverage becomes higher and higher, and artificial lawn planting industrial chain are thriving. Small-and medium-sized lawn mowing machines become widely used in many places such as parks, fields and turf planting bases. A conventional lawn mower comprises a chassis, an engine mounted on the chassis, and a grass cutter mounted under the chassis; the cutter is generally provided with a cutting blade that can be rotated at high speed; an output end of the engine crankshaft is mounted thereon with an engine pulley which drives a cutter shaft via a belt, thereby driving the cutting blade to rotate.

A lawn mower having only one cutting blade can cover a relatively small width in operation. In order to improve grass cutting efficiency, dual blade wide-format lawn mower emerged. A dual blade wide-format lawn mower employs two cutter shafts, with each cutter shaft mounted with a cutting blade on the lower end thereof. Conventionally, each of the two cutter shafts is mounted on the upper end thereof with a cutter shaft pulley which is driven by an engine pulley via a belt.

Chinese utility model patent publication number CN 210226224 U discloses a dual blade wide-format lawn mower wherein an engine is mounted on a chassis, and a grass cutter is provided under the chassis; the grass cutter comprises two cutter shafts parallel with each other; the two cutter shafts each are mounted with a cutting blade on an lower end thereof; the two cutter shafts each are mounted with a cutter shaft bevel gear on an upper end thereof, and each cutter shaft bevel gear is engaged with a transmission bevel gear mounted respectively on an outer end of a horizontal shaft; the two horizontal shafts are co-axial, and each horizontal shaft and the cutter shaft on the same side with said each horizontal shaft are supported respectively by a bearing in a cutter shaft seat; both cutter shaft seats are fixed onto the chassis, and opposing ends of the two horizontal shafts extend from the respective cutter shaft seat and each is mounted with a drum gear, and both drum gears are engaged respectively with spline internal teeth provided at both ends of an internally toothed sleeve; one cutter shaft has an upper end that extends from a top end of the respective cutter shaft seat and the upper end is mounted thereon with a cutter shaft pulley that is connected with an engine pulley via a cutter driving belt.

The two blades of the lawn mower of this patent can be used for simultaneous cutting at the same height; however, it has the following disadvantages:1. For a small-sized gas engine-powered wide-format rear-collection walking lawn mower, the front half comprises the cutter, and the rear half is installed with the engine; where a compact structure is required, such an arrangement cannot avoid the interference of the grass discharging channel and the engine arranged thereabove.2. The two cutting blades have the same diameter and completely symmetrical with each other; the two cutters of the same diameter discharge the grass backward from the middle thereof, and the angle of elevation of the discharge channel will be limited by the engine arranged thereabove, which makes the height of the outlet relatively small, and the flow rate and delivery speed of the channel cannot be guaranteed by the natural cyclone alone, resulting in possible clogging of the channel and the crushed grass is not able to enter the grass collecting basket completely, and thus exhibiting poor performance in grass collection.3. Where an additional fan is used to assist backward grass discharging from one side of the cutters, the cost will be high and the machine will not be stable.

SUMMARY OF THE INVENTION

It is an objective of the present invention to overcome the flaws present in prior art and provide a dual blade wide-format rear-collection lawn mower which can not only carry out grass cutting simultaneously at the same height with two interconnected blades, but also can ensure smooth grass discharge with natural air flow and achieve efficient grass collection.

For solving the technical problem described above, the present invention provides a dual blade wide-format rear-collection lawn mower comprising: a chassis, an engine mounted on an upper side of a rear portion of the chassis, and a grass cutter mounted on a lower side of a front portion of the chassis, wherein the grass cutter comprises a big grass cutter and a small grass cutter which are tangential to, and connected with, each other, the big grass cutter is provided with a long blade therein, and the small grass cutter is provided with a short blade therein, the long blade is fixed onto a lower end of a long blade shaft, and the short blade is fixed onto a lower end of a short blade shaft, both the long blade shaft and the short blade shaft are driven by the engine and rotated at the same direction, a grass discharging channel is positioned at a side where the big grass cutter is located, and an entrance of the grass discharging channel is connected in a smooth transition manner with an outer wall of the big cutter which is away from the small grass cutter, the grass discharging channel is tilted upward and backward and a grass discharging outlet thereof is connected with a grass collecting basket.

As an improvement of the invention, a vertical plane where the long blade shaft and the short blade shaft are located forms an angle with a width of the lawn mower, and the axis of the long blade shaft is closer to the rear side of the chassis than the axis of the short blade shaft.

As a further improvement of the invention, a deck of the grass cutter, the grass discharging channel and a seat plate of the engine are connected together as an integral part.

As a further improvement of the invention, the long blade shaft is installed on a top end thereof with a long blade shaft pulley set, and the short blade shaft is installed on a top end thereof with a short blade shaft belt wheel, and a short blade shaft idle pulley is installed over the short blade shaft belt wheel; a crankshaft of the engine is installed at a lower end thereof with a driving belt wheel for cutting, and the driving belt wheel for cutting is in transmission connection with the long blade shaft pulley set and the short blade shaft idle pulley via a first belt; and the long blade shaft pulley set is in transmission connection with the short blade shaft belt wheel via a second belt.

As a further improvement of the invention, the short blade shaft belt wheel has a diameter that is smaller than a diameter of the long blade shaft pulley set.

As a further improvement of the invention, the ratio of the diameter of the long blade shaft pulley set to the diameter of the short blade shaft belt wheel is equal to the ratio of the length of the long blade to the length of the short blade.

As a further improvement of the invention, the first belt has a loose side, the second belt has a loose side, and each loose side is pressed against a belt tension wheel.

As a further improvement of the invention, a driving belt wheel for walking is provided under the driving belt wheel for cutting, and the driving belt wheel for walking is integral with the driving belt wheel for cutting, the driving belt wheel for walking is in transmission connection with an input shaft belt wheel of a self-driving gear box via a third belt, and each end of an output shaft of the self-driving gear box is provided with a self-driving gear for driving the lawn mower to move.

As a further improvement of the invention, an arc brake plate is provided outside of the short blade shaft belt wheel, and an inner arc surface of the arc brake plate is configured to press against a backside of the second belt that is inserted in the short blade shaft belt wheel.

Compared to the prior art, the present invention has the following advantages:1. The two grass cutters are designed to have a deviated rear-collection grass discharging channel, and the grass discharging channel and the engine are apart when viewed from the top, which effectively avoids a spatial interference between the grass discharging channel and the engine, the up-tilted angle and height of the outlet of the grass discharging channel will not be restricted by the engine, and the effective cross-sectional area of the grass discharging channel can be increased, thereby decreasing the resistance to the discharge of the grass and avoiding clogging.2. In consideration of the deviated grass discharging channel, the two cutting blades are rotated in the same direction; since the ratio of the diameter of the long blade shaft belt wheel to the diameter of the short blade shaft belt wheel is equal to the ratio of the length of the long blade to the length of the short blade, the linear speed of the tip of the short blade is close to, or slightly greater than the linear speed of the tip of the long blade. The crushed grass cut by the rotation of the short blade at a higher speed enters the cyclone formed naturally by the high speed rotation of the long blade, thereby the crushed grass cut by both the long blade and the short blade are discharged in the same air flow smoothly and a satisfying grass collection can be achieved.

DETAILED DESCRIPTION OF THE INVENTION

In the description of the present invention provided below, the terms indicating directional or positional relationships such as “up”, “down”, “above”, “over”, “under”, “front”, “rear”, “left”, “right”, “inner”, “inside”, “outer” and “outside” are based on the directional or positional relationships shown in the accompanying drawings and used merely for facilitating the description of the present invention and making the description simple, but not for defining that the components must have the particular directions and/or positions.

In order to obtain a better understanding of the technical means, features for carrying out the invention and the objectives achieved therefrom, the invention will be further described below with reference to the accompanying drawings.

Unless otherwise defined, the technical and scientific terms used herein have the same meaning commonly understood by one skilled in the art. The terms used herein are merely used to describe the particular embodiments of the invention, but not intended to limit the scope thereof.

As shown inFIGS.1-6, the dual blade wide-format rear-collection lawn mower of the present invention comprises a chassis1, a grass cutter, an engine2and a grass collecting basket14. The upper side of the rear portion of the chassis1is provided with an engine seat plate1ewith an engine2installed thereon. The lower side of the front portion of the chassis1is provided with the grass cutter, and the grass cutter comprises a big grass cutter1band a small grass cutter1cwhich are tangential to, and connected with, each other. The big grass cutter1bis provided with a long blade3atherein, and the small grass cutter1cis provided with a short blade4atherein. The long blade3ais fixed onto the lower end of the long blade shaft3, and the short blade4as fixed onto the lower end of the short blade shaft4.

The long blade shaft3is supported in a long blade shaft seat via a bearing, and the short blade shaft4is supported in a short blade shaft seat via a bearing. The peripheral of the upper portion of the long blade shaft seat and the peripheral of the upper portion of the short blade shaft seat each are provided with a blade shaft seat flange and the two flanges each are fixed under a grass cutter deck1aby a bolt.

The chassis1is further provided with a grass discharging channel1d.The grass discharging channel1dis positioned at the side where the big grass cutter1bis located, and the entrance of the grass discharging channel1dis connected in a smooth transition manner with the out wall of the big cutter1bwhich is away from the small cutter1c.The grass discharging channel1dis tilted upward and backward and the grass discharging outlet1fat the backend thereof is connected with the grass collecting basket14.

The long blade3aand the short blade4aare rotated in the same direction. The crushed grass cut by the high speed rotation of the short blade enters naturally, along the tangent direction, the cyclone formed naturally by the high speed rotation of the long blade3a,and travels with the crushed grass cut by the long blade3ainto the grass discharging channel1d,and then they enter the grass collecting basket14from grass discharging outlet1fat the backend of the grass discharging channel1d.

The vertical plane where the long blade shaft3and the short blade shaft4are located forms an angle with the width of the lawn mower. The axis of the long blade shaft3is provided closer to the rear portion of the chassis1than the axis of the short blade shaft4such that the length of the grass discharging channel1dis shortened, thereby decreasing the resistance to the discharge of the grass.

The engine crankshaft2ais provided at the lower end thereof with a driving pulley for cutting2b,and a driving pulley for walking2cis provided thereunder, and the driving pulley for walking2cis integral with the driving pulley for cutting2b.

The long blade shaft3is installed on the top end thereof with a long blade shaft pulley set3b,and the short blade shaft4is installed on the top end thereof with a short blade shaft pulley4b.A short blade shaft idle pulley4cis installed over the short blade shaft pulley4b.

The driving pulley for cutting2bis in transmission connection with the long blade shaft pulley set3band the short blade shaft idle pulley4cvia a first belt5which is inserted in a first belt groove of the long blade shaft pulley set3b.A first tension wheel5ais provided between the short blade shaft idle pulley4cand the driving pulley for cutting2b, and the first tension wheel5ais provided against the loose side of the first belt5.

A second belt groove of the long blade shaft pulley set3bis in transmission connection with the short blade shaft pulley4bvia a second belt. A second tension wheel6ais provided against a loose side of the second belt6. The diameter of the short blade shaft pulley4bis smaller than the diameter of the long blade shaft pulley set3b, such that the rotation speed of the short blade4ais greater than the rotation speed of the long blade3a.

As a preferable embodiment, the ratio of the diameter of the long blade shaft pulley set3bto the diameter of the short blade shaft pulley4bis equal to the ratio of the length of the long blade3ato the length of the short blade4a,such that the linear speed of the tip of the short blade4ais equal to linear speed of the tip of the long blade3a, which is more helpful for the crushed grass cut by the short blade4aenters naturally, in the tangent direction, the cyclone formed by the high-speed rotation of the long blade3a.

A arc brake plate10ais provided outside of the short blade shaft pulley4b,and the inner arc surface of the arc brake plate10ais configured to press against the backside of the second belt6that is inserted in the short blade shaft pulley4b.The base portion of the arc brake plate10ais connected with the base portion of the brake arm10as an integral body, and the base portion of the brake arm10is a connecting end and hinged to the pivot11. The free end of the brake arm10is in hinged connection with a brake-clutch pull cord13extending backward and a brake spring12extending forward. Additionally, the swing arm of the first tension wheel5acan move together with the brake arm10.

When the brake-clutch pull cord13is pulled backward, the brake arm10will rotate forward around the axis of the pivot11, and with the release of the first tension wheel, the arc brake plate10ais disengaged, or in a slight contact with the second belt6. When the brake-clutch pull cord13is released, the pull force of the brake spring12will reset the arc brake plate10a,that is, the arc brake plate10awill be pressed against the backside of the second belt6, and brake is achieved by the friction therebetween.

The driving pulley2cfor walking can be smaller than the driving pulley2bfor cutting, and accordingly, when they rotate at the same speed, the linear speed of the driving pulley2cfor walking will be smaller. The input shaft of the self-driving gear box8is mounted with a self-driving input pulley8a,and the driving pulley2cfor walking is in transmission connection with the input pulley of the self-driving gear box8via a third belt7, and the loose side of the third belt7is pressed against a third tension wheel7a.Each of the two ends of the output shaft of the self-driving gear box8is provided with a self-driving gear9. With the design descried above, one engine can not only drive the blades to cut, but also drive the lawn mower to move.

The embodiments described above are merely preferred ones for carrying out the present invention, which show and describe the basic principle, main features and advantages thereof, and they are not intended to limit the scope of the present invention. One skilled in the art would understand that the present invention should not be limited to the embodiments as described above. The present invention may also be implemented in other embodiments in addition to these embodiments without departing from the spirit and scope of the present invention. Various changes or modifications may be possible and all technical solutions obtained by equivalent replacements or equivalent modifications shall fall within the scope of the present invention. The scope of the present invention will be defined by the appended claims and the equivalents thereof. The features that are not described in this application can be carried out by or using prior art, and thus will not be repeated herein for brevity.

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