DE1507434B1 - Slipping clutch for horizontally rotating, motor-driven blades of a lawn mower - Google Patents

Claims (2)

1 2 The invention relates to a slip clutch for a screw is built into the shaft end 1 horizontally rotating motor-driven screwed and has a head 9, which is a Knife of a lawnmower with a washer on the lower part of the coupling upper part Coil spring attached to the end of the motor shaft holds a 10. Knife holder against a rotationally fixed to the motor shaft 5 A socket 11 is attached to the screw 8 The coupling part presses and the knives, which hold open through the on the screw is arranged on the motor shaft that it is held screwed nut 12 and to the opposite its plane of rotation is used by a stop loading support of a disk spring stack 13, which is adjacent is tiltable. whose end lies against a thrust bearing 14, wel-um when the knife hits an obstacle ίο this is on a section 15 of the coupling company, z. B. a larger stone, the motor shaft or partly 7 is supported. Not to damage the engine, it is known that with the help of screws 16 and nuts 17, the lawnmower of the type in question between knife 18 is attached to the coupling lower part 7, the motor and the knife a slip clutch that there is some distance from to arrange the contact, which the engine torque is on the 15 surfaces 5 and 6 of the coupling parts 3 and 7.
Knife transfers. When the knife hits a stop and friction ring 19, the knife can stop with the help of an obstacle, while screws 20 and nuts 21 are attached to the mower hood 22 as a result of the slip coupling. It can also develop the stop and friction ring, the motor shaft continue to run without damage 19 with the mower hood 22 form one piece. He can. In a known lawnmower of this type 20 ring 19 has an inner circumferential profile 23, welist over the lower part of the motor shaft a sleeve chem one in normal operation it is somewhat relieved, in which a helical spring is supported distantly opposite projecting circumference, which is one of several clutch disks - profile 24 of the coupling lower part 7 corresponds,
Standing package that accommodates the knives. The coupling works as follows: In the standard with a predetermined preload against malfunction, the torque of the motor shaft 1 is pressed on the enlarged head of the motor shaft. over the two by the disc springs 13 on their It is the object of the present invention to provide a contact surface 5 and 6 in frictional engagement. Slipping clutch of the type described in more detail at the beginning of the clutch parts 3 and 7 on the knife 18 over- to continue training so that the motor shaft and thus carry. also the motor not only against a too high 30 If the knife hits an unyielding hindrance Torque load when the knife hits, z. B. a larger stone or a single is protected on an obstacle, but at the same time beaten pipe to accommodate a laundry even against excessive bending moments, the pile here, it is suddenly stopped while the can arise. Inertial forces of the motor drive shaft 1 further According to the invention, this object is thereby turned. Since the coupling parts 3 and 7 do not solve the problem that a flange of the knife holder is connected to each other, but rather plate springs 13 are held in frictional engagement only by the impact of a ring attached to the mower housing, which interacts when the knife holder is tilted. In this way, the coupling upper part 3, which continues to rotate, can be ensured that when the coupling knife, which is held by the knife, hits an obstacle, the resulting 40 lower part 7 slip. If the bending moments are correctly dimensioned, the disc springs 13 are not transferred to the motor shaft, the torque that can be transferred to the coupling parts is limited to a knife age and the resulting investment of the value below a dangerous flange of the knife holder on the The torsional stress on the motor shaft 1 stops.
Mower housing on the mower housing immediately 45 Since furthermore the knife 18 on the coupling are lowered. part 7 on one of the contact surfaces 5 and 6 Advantageously, the contact between the coupling parts 3 and 7 are attached at a remote location surfaces of the coupling part and knife holder is conical, tilts on the knife 18 when it hits designed so that the knife holder is under the same auftre action on an unyielding obstacle the spring force of the slip clutch after 50 tend reaction force the clutch lower part 7 against Center the tilting again automatically at any time over the upper coupling part 3 in the position shown in FIG. 2 darkann, posed way, eliminating the protruding profile The invention is illustrated below with reference to the schematic 24 of the coupling lower part 7 with the corresponding table Drawings of an embodiment, the profile 23 of the stop and friction ring 19 in closer explained. It shows 55 emotion is coming, which brings about the energy released Fig. 1 is a schematic section in one of the fixed ring 19, the mower hood 22 and the not The plane of rotation of the mower contained in the plane is transmitted through one of the illustrated wheels of the mower and through Slipping clutch according to the invention and the friction thereof on the ground is consumed. F i g. 2 partly in section, partly in side This is a bending stress of the looks at the position of the knife holder under the An 60 motor shaft 1 prevented, assume that the knife has hit an obstacle. Through the above training, an over- In the case of the mower shown in the figures, moderate torsional and bending stresses on a motor shaft 1 are definitely avoided by means of a wedge 2,
Upper part 3 attached, which forms a pulley 4 and a conical contact surface 5. 65 claims:
The latter works together with a corresponding contact surface 6, which is formed on a clutch 1. Slipping clutch for horizontally rotating lower part 7. of the motor-driven knife of a lawn mower, in which a coil spring attached to the lower end of the motor shaft has a knife holder presses against a coupling part connected to the motor shaft in a rotationally fixed manner and the knife holder is arranged on the motor shaft that it is opposite to its plane of rotation by a stop is tiltable to a limited extent, characterized in that a flange (24) of the knife holder (7) with the stop (23) of the Mower housing (22) attached ring (19) cooperates when tilting the knife holder. 2. Slipping clutch according to claim 1, characterized in that the contact surfaces of Coupling part and knife holder are conical. 1 sheet of drawings COPY