Lawnmowing apparatus having grass collector fullness detector with elastic membrane

• US 5,775,077 A
• Filed: 05/31/1996
• Issued: 07/07/1998
• Est. Priority Date: 05/31/1996
• Status: Expired due to Term

• Current Assignee: Jaroslav O. Olmr
• Original Assignee: Jaroslav O. Olmr
• Inventors: Olmr, Jaroslav O.
• Primary Examiner(s): Melius, Terry Lee
• Assistant Examiner(s): Pezzuto, Robert
• Application Number:
  US08/655,855
• Time in Patent Office: 767 Days
• Field of Search: 56/194, 56/199, 56/200, 56/201, 56/202, 56/203, 56/10.2 R, 56/28, 56/30
• US Class Current: 56/202
• CPC Class Codes: A01D 2101/00 Lawn-mowers
• CPC Class Codes: A01D 34/63 having cutters rotating about a vertical axis
• CPC Class Codes: A01D 43/0631 Control devices specially adapted therefor
• CPC Class Codes: Y10S 56/08 Air gathering

Abstract

A lawnmower includes a grass collector bin connected to a rotary blade by a chute. Mounted on the chute is a pressure-sensitive detector which senses when the bin is full, on the basis of a given pressure increase in the chute. The detector includes a microswitch having a sensing arm which contacts a center portion of an elastic membrane. The membrane communicates with the chute such that the center portion of the membrane is deflected in response to a given pressure increase in the chute, in order to actuate the switch. The membrane includes a bellows portion for increasing the distance by which the membrane can be deflected in response to the given pressure increase.

Claims

1. A lawnmower including:

a cutting chamber and a rotary cutter blade therein;

an air flow passage through which grass cuttings are discharged from said cutting chamber in a current of air;

a collector connected to said passage for accumulating said grass cuttings; and

a detector responsive to an air pressure condition within said passage to change a state of said detector under a predetermined pressure condition related to a fullness of said collector, said detector including;

an elastic membrane covering an opening arrangement formed in a wall of said passage to communicate a first side of said membrane with pressure in said passage;

a switch including a sensing arm engageable with a second side of said membrane to be displaced in response to pressure-induced deflection of a contact region of said membrane contacted by said sensing arm; and

said membrane having formed therein a pleated structure surrounding said contact region and defining a bellows portion for increasing a displacement distance of said contact region of said membrane.

2. The lawnmower according to claim 1 further including an operator'"'"'s seat, and a driven ground support wheel.

3. The lawnmower according to claim 1, wherein said membrane is circular, and said bellows portion is circular.

4. The lawnmower according to claim 1, wherein an outer portion of said membrane bears directly against an outer surface of said wall.

5. The lawnmower according to claim 4, said detector further including a clamping plate clamping an outer periphery of said membrane against said wall of said passage.

6. The lawnmower according to claim 5, wherein said switch is mounted on said clamping plate.

7. The lawnmower according to claim 6 further including a baffle projecting into said passage from said wall to form with said wall a zone of less cross section than said passage, said zone communicating said opening arrangement with said passage at a location downstream of said opening arrangement.

8. The lawnmower according to claim 1, wherein said opening arrangement comprises a plurality of small openings.

9. The lawnmower according to claim 1 further including a cover overlying said switch and said membrane.

10. The lawnmower according to claim 1, wherein said opening arrangement comprises a single large opening.

11. A lawnmower including:

a cutting chamber and a rotary cutter blade therein;

an air flow passage through which grass cuttings are discharged from said cutting chamber in a current of air;

a collector connected to said passage for accumulating said grass cuttings; and

a detector responsive to an air pressure condition within said passage wherein said air pressure condition changes a state of said detector under a predetermined pressure condition related to a fullness of said collector, said detector including;

an elastic membrane covering an opening arrangement formed in a wall of said passage to communicate a first side of said membrane with pressure in said passage, said membrane bearing directly against an outer surface of said wall; and

a switch including a sensing arm engageable with a second side of said membrane to be displaced in response to pressure-induced deflection of said membrane.