FR2773945A1 - ROTARY LAWN MOWERS - Google Patents

Abstract

A rotary lawn mower has an outlet passage through which clippings of grass are ejected from a cutting chamber. A safety shutter is movable against an elastic return from a partially open position, to a fully open position relative to the outlet passage. Additional elastic means allow movement of the safety shutter in the opposite direction, from its partially open position towards a closed position with respect to the outlet passage.

Description

ROTARY LAWN MOWERS

  The present invention relates to a rotary lawn mower, in which a rotary knife blade is placed in a cutting chamber below a protective casing, and in which grass clippings are removed from the cutting chamber. through an exit passage. In such a lawn mower, it is common practice to place a safety shutter across the outlet passage. At rest, the flap is returned by spring towards a closed position, and it is manually pivoted upwards against the spring return towards an open position, when the

  exit with a device to collect the grass.

  However, circumstances may arise in which the user wishes to operate the lawn mower without picking up the grass clippings. For this reason, the flap does not completely close the outlet passage when it is called back to its closed position, but it remains partially open. For safety reasons, the opening is sufficient to allow the passage of the clippings of grass, which are then deposited on the ground, but it is insufficient to allow

  the user to access the rotating blade.

  A known method for creating the partial opening is to mold the safety flap with relatively deep side pieces, which abut against a vertical surface at the rear of the casing of the mower. In this way, the safety flap is recalled to a position, in which it remains slightly inclined relative to the vertical surface, at an angle of approximately, and advancing from the rear of the casing of the mower. This is a disadvantage for the manufacturer, -2when he packs the mower since, in order to accommodate the advancing flap, the packaging box must be more

  important, than what would otherwise be necessary.

  According to the present invention, a rotary lawn mower, which has a movable safety flap against an elastic return, from a partially open position across an outlet passage communicating with a cutting chamber towards a completely open, includes additional elastic means allowing movement of the security flap in the opposite direction from its position

  partially open towards a closed position.

  According to a preferred embodiment, the flap is movable from its partially open position to its fully open position against the return of a first spring, and is also mobile against the return

  of a second spring towards its closed position.

  The first spring preferably includes a coil torsion spring, and the second spring is preferably a lever spring. In one of the particular embodiments, the two springs are formed as a unit in one piece, from a length

single wire.

  In the accompanying drawings, by way of example only: - Figure 1 is a schematic view of a lawn mower comprising a safety flap across the outlet channel of the cutting chamber; - Figure 2 is a plan view of the security shutter; - Figure 3 is a section along line C - C in Figure 2; - Figure 4 is a side elevation of the flap; - 3 - - Figure 5 is a side elevation of a spring assembly intended to return the flap; and - Figure 6 is a front view of the assembly

forming spring.

  Referring to these drawings, a rotary lawn mower 10 comprises a knife blade 12 which can rotate about a vertical axis in a cutting chamber 13 formed below a protective cover 11. The blade is driven by a motor electric (not shown), also enclosed under the hood. The grass clippings are made to grow from the chamber 13, by the edges facing upwards of the knife blade in a flow of air created by a fan 19, and they are ejected in a manner

  well known backwards through an outlet channel.

  A safety flap 36 is mounted so as to pivot, at the rear of the mower across the outlet channel. The flap pivots on a horizontal rod 37 disposed at the rear upper portion of the mower housing, and it comprises surface side walls 48a, 48b having aligned openings 49a, 49b intended to receive the rod 37. In conventional use, the flap 36 is raised from the partially open position shown in FIG. 1, to a fully open position against the return of a torsion coil spring 38, disposed on the rod 37, and the rear is then fitted with the mower with a grass container (not shown). In its fully open position, the flap then rests on the cover of the grass container, and automatically falls back to its partially open position across the outlet channel, when the grass container is removed in order to

empty it.

  In practice, the user of the mower may occasionally wish to mow the grass without mounting the grass container. In this case, it is important that the flap 36 must not completely block the outlet channel, but must remain partially open in order to avoid obstructing the channel. This is accomplished by establishing the coil torsion spring 38 with a deploying arm 39, which acts as a leaf spring pressing the shutter outward to its partially open position. The torsion spring 38 and the deploying spring 39 therefore act in opposite directions. A particular advantage of this arrangement is that the flap 36 can be pressed towards a closed position (shown in dotted lines in FIG. 1) against the return of the deploying spring 39, when the mower is packaged in a box. 'packaging. As a result, a particularly compact rectangular package is produced, with the handle (not shown) folded over the casing of the

mower 11.

  The combined springs 38, 39 are formed from a length of cold drawn carbon steel metal wire, the torsion spring 38 consisting of coils tightly wound 41 on the rod 37. The coils are positioned on the portion of the rod which passes through one of the wing portions 42a, 42b, of the flap 36, on each side of a hollow central portion constituting a handle, intended to lift the rear of the mower. The short deploying arm 44 is then fixed at a location inside the rear of the mower housing, while the long deploying arm 39 has its free end arranged in

  a tab 45 formed on the inner surface of the flap 36.

  The deploying arm 39 comprises a curvature 46 which abuts against a projection at the rear of the mower housing, so that when the flap 36 is pressed towards the rear face of the mower housing, the arm deploying 39 is straightened and acts as a spring

blade.

  -5 - In this way, at rest, the flap 36 is recalled by the spring 39 to a position inclined outward relative to the rear face of the mower housing, but it can be pressed against the return of the spring 39 towards a substantially vertical position, flush with the

  rear side of the mower housing.

-6 -

Claims (8)

  1. Rotary lawn mower comprising an outlet passage, through which grass clippings are ejected from a cutting chamber, a movable safety flap against an elastic return from a position partially opened by relative to the outlet passage to a fully open position, and elastic means   additional allowing movement of the security flap in the opposite direction from its partially open position towards a closed position10 relative to the outlet passage.   2. Lawn mower according to claim 1, in which the shutter is movable from its partially open position to its fully open position against the return of a first spring, and in which said additional elastic means comprise a second spring.   3. Lawn mower according to claim 2, wherein the first spring comprises a torsion spring with sausage.   4. Lawn mower according to claim 3, wherein the second spring comprises a spring forming the sink.   5. Rotary lawn mower according to claim 4, wherein the two springs are formed as a single unit from a single length of wire metallic.   -7 - 6. Lawn mower according to claim 4 or 5, in which the safety flap is mounted on a rod so as to pivot, and in which the torsion spring comprises a coil wound helically. arranged around the stem.   7. A lawn mower according to claim 6, wherein one end turn of the spool wound so   helical extends downward from the rod to form the lever spring.   8. A lawn mower according to claim 7, wherein a first turn of the spool wound so   helical extends downward from the rod and attaches to the body of the lawn mower.