GB2175483A - Lawn mower - Google Patents

Abstract

A lawn mower comprising a wheeled machine body (4), a drive engine (6) mounted on the machine body (4), a rotary cutting blade (7) driven by the engine (6), and a steering handle (8) having a pair of laterally spaced arm sections (8a) co-extending rearwardly from the machine body, wherein a bonnet (5) has a maximum width larger than an interval between the arm sections and is freely hinged to a rear end portion of the machine body, the bonnet being pivotal between its closed position covering the engine and its fully opened position resting on the arm sections. <IMAGE>

Description

SPECIFICATION Lawn mower This invention relates to a lawn mower, and more particularly to an improved power lawn mower having an engine covering bonnet.

A power lawn mower is equipped with an engine for driving a cutting blade, and typical examples thereof are disclosed for example in FR-A-2 415 952, GB-A-2 130 466 (FR-A-2 5341 772), and BE-A-894.048. In the conventional power lawn mowers, the engine on a machine frame or body is generally not provided with any protective cover or hood from the economical viewpoint Thus, the engine is exposedto the atmosphere.

However, it is apparent that the exposure ofthe engine to the atmosphere is disadvantageous because of poor appearance, lowsafety, and noise disturbance. More specifically, the exposure ofthe enginetogetherwith its associated components such as afuel tank and an airfilter not only reduces the visual attractiveness of the lawn mower but also increases the likeliness of the usersuffering a burn by accidentally touching the heated engine. In use of the mower in a residential area, which is often the case, non-muffled noises from the exposed engine causes a disturbance to the neighborhood. Further, the exposed engine is liable to dust deposition which is likely to give adverse influences to the engine.

These problems can be simply solved by covering the engine with a bonnet which can be raised opento provide an easy access to the engine when required for maintenance, inspection and repair. Thus, provision of such a pivotal bonnet is in fact requested by the users.

In a simplest arrangement, such a protective bonnet may be pivotally mounted to the machine body by hinges of a self-stopper type, which by themselves supportthe pivotal bonnet in its raised open position.

However, this arrangement has a drawbackthat a considerable moment depending on a weight of the bonnet is inevitably applied to the hinges every time thebonnetis pivoted open.Thus, after repeated opening and closing operations of the bonnet, the hinges are damaged, and the bonnet and the machine body may be locally deformed at the hinge connection.

Alternatively, the bonnet may be pivotallyconnected to the machine body by means of free hinges.

In this case, however, an extra means is required for holding the bonnet at its raised-open position, consequently complicating the structure ofthe mower and increasing the overall weightthereof.

It is, therefore, an object of the present invention to provide a bonneted power lawn mowerwhich is simple in construction, inexpensive in manufacture, and has a sufficient durability at the hinge connection which withstands repeated opening and closing operations of the bonnet According to the present invention, there is provided a lawn mower comprising a wheeled machine body, a drive engine mounted on the machine body, a rotary cutting blade driven by the engine, and a steering handle having a pair of laterally spaced arm sections co-extending rearwardlyfrom the machine body, characterized in that a bonnet has a maximum width or crosswise dimention largerthan an interval between the arm sections and is freely hinged to a rear end portion of the machine body, the bonnet being pivotal between its closed position covering the engine and its fully open position resting on the handle arm sections.

By covering the engine and its associated components withthe bonnet, the lawn mower provides an attractive appearance, facilitates reduction in the operating noises of the engine, and prevents a user from coming into an inadvertent contact with the heated engine and thereby from suffering a burn.

On the other hand, the bonnet is formed so asto be supported in its fully opened position by the steering handle which is originally present, thus dispensing with any extra means for holding the bonnet in its fully opened position, thereby to avoid any structural complication as well as undesirable cost and weight increase. The steering handle supports thefully opened bonnet at a position sufficiently remote from the h i nge con neetio n, so that the hinge connection is notsubjectedto any undue moment resulting from the weight of the bonnet in utilization of the principlesof the lever and fulcrum. Therefore, the hinge connection is free of damage and deformation to ensure a longer service life without requiring any extra reinforcement.

According to a preferred embodiment ofthe present invention,the bonnet is stepped along a contour line thereofto provide a pair of rising walls and a pair of abutment walls disposed on either side of the bonnet, and the rising walls and the abutment walls extend in parallel with a longitudinal axis of the machine body, the abutment walls being rested on the arm sections ofthe steering handle while each ofthe rising walls being in contact with an inner side wall of each of the arm sections ofthe steering handle when the bonnet is in its fully opened position.

This arrangement assures stability ofthe bonnet in its fully opened position since the bonnet is restricted from lateral displacement which may adversely affect the hinge connection. Further, the stable support of the bonnet also enables running ofthe lawn mower with the bonnet properly kept open when such is desired.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a lawn mower embodying the invention, with its bonnet closed; Figure 2 is an enlarged side elevation of the lawn mower, in which a fully opened position of the bonnet is shown in phantom line; Figure 3 is a top plan view ofthe lawn mower; Figure 4 is a cross section ofthe bonnet taken on lines 4-4 in Figure 2 as viewed in the direction ofthe arrows; Figure 5 is a longitudinal section ofthe bonnet; Figure 6 is a longitudinal section taken on lines 6-6 in Figure 3, with a pivotal movementofthe bonnet shown in phantom lines; Figure 7 is an enlarged cross section of the bonnet taken on lines 7-7 in Figure 3 as viewed in the direction ofthearrowswith parts cut away; and Figure 8 is a longitudinal section taken on lines 8-8 in Figure 7.

Referring nowto the drawings, a lawn mower 1 is illustrated as having a machine body 4 supported on a pair of frontwheels 2 and a pair of rea r wheels 3 for movement in a known fashion. An engine 6 is mounted on the machine body4to drive a rotary cutting blade7through an output shaft 6a extending downwardly from the engine (Fufyre 2). The mower 1 also has a steering handle8which extends rearwardly from the machine body 4 in an inclinded fashion. Both pairs ofthe wheels 2,3 may be freely rotatable.

Preferably, however, one pairthereof may be oper atively connected to a known unillustrated propeller shaftextendedfromthe engine6to enablethe self-propelling ofthe mower More particularly, the machine body 4 comprises a lower chassis 4a at which the wheels 2,3 are rotatably supported conventionally, and an upper housing4b formed integral with thechassis4ato enclose the engine6.The chassis4a isformed with a room 9 accommodating the rotary cutting blade - 7 operatively connected to the vertical output shaft 6a.The housing is provided with a cut-off lawn discharge passage 10 which is substantialiy spiral in form and communicatesthe room 9 and has an outlet 13forcommunica- tion with catcher bag 11 attached to the rear end ofthe housing 4b. Thus, the cut-off lawn is centrifugally transferred from the room 9 through the discharge passage 10 into the bag 11.

The steering handle 8 isformed of a metal tube or bar by bending it. The steering handle 8 includes a pair oflaterally spaced arm sections 8a which extends in parallel and atthesame inclination angle with each other. The arm sections 8a are joined together at their respective rear ends by an uprising U-shaped section including a horizontal bar section 8d which services as a grip forsteering.The handle 8 is connected, preferably detachably, at their respective front ends to the rearendofthe machine housing 4bwith the aid of suitable fittings 12 fixed to the housing 4b. In casethe machine body4 is devoid ofthe housing 4b, the handle may be fixed to the chassis 4a by means of unillustrated brackets provided on the chassis.

Each of the arm sections 8a isslightly convexly curved at its intermediate point to provide a front portion 8b and a rearportion 8c, in whichthefront portion 8b is steeper in inclination angle than the rear portion 8c, as illustrated.

The above described structure and arrangement are conventional and in no way constitutes the subject of the present invention. Thefeatures ofthe invention reside in thefollowing specific construction and arrangement of a bonnetcoveringtheengine6.

According to the invention, the lawn mower 1 further includes a bonnet5which is selectively pivital to its closed position (indicated in solid lines in Figures 2and 3)forcovering the engine 6andto itsfully opened position (indicated in phantom lines in Figures 2 and 3) for providing access to the engine 6. For this purpose, the bonnet S is pivotally connected to the rear end ofthe machine housing 4b by means of free hinges 14.

As best illustrated in Figures 3and 4, the bonnet5 has its maximumwidth largerthan the interval between the parallel arm sections 8a ofthe steering handle 8 sothatthe bonnet5 can be rested on the arm sections 8a when the bonnet is raised open to its maximum extent.

According to the illustrated embodiment, the bonnet 5 is substantially semi-spherical in cross section but stepped at a contour line 15 to provide an abutment wall 1 5a and a rising wall lsb on each ofthe opposite sides thereof, as best shown in Figure 5. The walls 1 Sa, 1 Sb extend in parallel with a longitudinal axis of the machine body with in a limited range, as best shown in Figure 3. The stepped portion 15 ofthe bonnet 5 isformed so thatthe walls 1 Sa, 1 Sb on either side ofthe bonnet are in contactwith the arm sections 8a ofthe steering handle 8 when the bonnet 5 is in its rest position (fully opened position), as best shown in Figure 4.

For the convenience of opening and closing ofthe bonnet 5, an inverted U-shaped knob 16 having a pair of legs 1 6a is attached to the front end ofthe bonnet 5.

To this end, each of legs 1 6a has a threaded lower end 1 6b extended through the wall thickness ofthe bonnet 5 for screw engagementwith a nut 18 on the internal wall ofthe bonnet5, as illustrated in Figure 7.

Forthe purpose offirmly maintaining the bonnet 5 in its closed position, an engaging means 17 is provided internally ofthe bonnet 5.,The engaging means 17 may include a fixing member 20 and a cooperating cross pin 22. The fixing member 20 is supported bya mounting strip 19 which is clamped at its holed opposite ends by means ofthethreaded ends 16b ofthe legs 16a and the nuts 18 as bestshown in Figure 7. The fixing member 20 is clamped to the mounting strip 19 by means of a screw 23 and a nut 24.

The fixing member 20 has a pair of opposed elastic pinching lips 20a extending downwardlyfor engage mentwiththecross pin 22which is mounted own a U-shaped bracket 21 fixed in position to the housing 4b.

When the bonnet5 is in its closed position, the cross pin 22 is clamped between the pinching lips 20a. when the bonnet 5 is raised open by an operator's pulling up the knob 16, the pinching lips 20a is simultaneously pulled uptherebyto release the cross pin 22.

It is obvious that the illustrated engaging means 17 maybe replaced by any other suitable forms such as for example the one utilizing a hook. In casethe machine body 4 has no housing, a suitable bracket (not shown) disposed on the chassis 4a may be utilized forthe same purpose.

In operation, the lawn mower 1 ,with its bonnet 5 held in its closed position,travels on the lawn ground to mowthe lawn. During this performance, the bonnet 5 prevents the user from accidentally coming into direct contact with the heated engine 6to suffer a burn and reduces noises in addition to providing at attractive appearance.

To open the bonnet 5 forthe maintenance or repair ofthe engine 6, the knob 16 is pulled upto cause the pinching lips 20a to elastically disengage from the cross pin 22, which results in the free pivotal movement ofthe bonnet 5 until it is rested on the pair of arm sections 8a ofthe handle 8 along the walls 15a, 16b on either side ofthe bonnet 5. In this condition, the bonnet 5 is supported art a point remote from the hinges 14, so that the weight ofthe bonnet 5 does not leadtoanylargemomentatthe pivotal connection including the hinges 14 ofthe bonnet Sto the machine housing 4b.Therefore, the hinges 14, the machine housing 4b and thebonnet5 arefree of damage and deformation even after repeated opening and closing operations ofthe bonnet 5.

The bonnet 5 at its fully opened position is restrained from undesirable lateral displacement because each ofthe rising walls 1 5b is in contact with an inner side ofthe arm sections 8a of the handle 8 on either side of the bonnet 5, with the resultthat any adverse influences attendant with such lateral displacement can be avoided atthe pivotal connection of the bonnet 5 to the machine housing 4b.

The described stepped configuration of the bonnets enhances the mechanical strength thereof to permit a smallerwallthickness, hence contributing to the overall weight reduction.

When designing the lawn mower 1, it is possible to provide a sufficient length of contact areas between the bonnet walls 1 5a, 1 5b and the pair of arm sections 8a ofthe steering handle 8, which contributes to dispersion of shocks which may occurwhenthe bonnet 5 is fully opened onto the arm sections 8a, wherebyoccurrenceofundesirabledeformation of the bonnet 5 can be minimized.

Claims (7)

1. A lawn mower comprising a wheeled machine body, a drive engine mounted on the machine body, a rotary cutting blade driven by the engine, and a steering handle having a pair of laterally spaced arm sections co-extending rearwardlyfrom the machine body, characterized in that a bonnet has a maximum width largerthan an interval betweenthe arm sections and isfreelyhingedtoa rear end portion ofthe machine body, the bonnet being pivotal between its closed position covering the engine and its fully opened position resting on the arm sections.

2. A lawn mower according to claim 1, wherein the bonnet is stepped along a contour line thereof to provide a pair of rising walls and a pairof abutment walls disposed on either side ofthe bonnet, and the rising walls and the abutmentwalls extend in parallel with a longitudinal axis of the machine body, the abutmentwalls being in contact with the arm sections ofthe steering handle when thebonnet is in its fully opened position.

3. Alawn moweraccording to claim 2, wherein each ofthe rising walls is contactwithaninnerside wall of each of the arm sections of the steering handle when the bonnet is in itsfullyopened position.

4. A lawn mower according to any one of the preceding claims, wherein the bonnet is provided at its front end with an externally projecting knob for facilitating opening ofthe bonnet.

5. A lawn mower according to any one ofthe preceding claims, further comprising an engaging means for releasably holding the bonnet in its closed position.

6. A lawn mower according to claim 5, wherein the engaging means comprises a fixing membersecured to the bonnet and having a pair of opposed pinching lips and a cross pin engageable with the pinching lips and supported on a U-shaped bracket secured two the machine body, the cross pin being releasable from the pinching lipswhenthe bonnet is opened.

7. A lawn mowersubstantially as hereinbefore particularly described with reference to, and as illustrated in Figures 1 to8ofthe accompanying drawings.