초록

The present invention relates to a lawn mower with a handle assembly comprising a lower frame and an upper frame which can be rotated to adjust its position with respect to the lower frame.

대표청구항 ▼

What is claimed is: 1. A grass mower comprising: a main body provided with a first and second side capable of guided movement adjacent to and over the ground; a motor contained in a motor housing of the main body; a cutting unit driven by the motor disposed in the motor housing; an elongate handle

What is claimed is: 1. A grass mower comprising: a main body provided with a first and second side capable of guided movement adjacent to and over the ground; a motor contained in a motor housing of the main body; a cutting unit driven by the motor disposed in the motor housing; an elongate handle assembly extending rearwardly from the main body into a handle to permit an operator to guide the main body during its guided movement over the ground, wherein the elongate handle assembly includes a lower frame including a pair of lower arms each having a proximal end secured to the first and second side of the main body respectively and a distal end to form a first joint portion and an upper frame provided with a second joint portion; an elongate shaft for pivotally coupling the second joint portion to the first joint portion such that the relative position of the upper frame and the lower frame is rotationally adjustable; a first engaging unit carried on the first joint portion and a second engaging unit carried on the second joint portion, wherein either the first engaging unit is equipped with a plurality of engaging points which is disposed along an arc around the elongate shaft, wherein the second engaging unit is selectively engageable with more than one selected one or set of the plurality of engaging points, or the second engaging unit is equipped with a plurality of engaging points which is disposed along an arc around the elongate shaft, wherein the first engaging unit is selectively engageable with more than one selected one or set of the plurality of engaging points; and at least one locking arrangement for locking the position of selected engagement of the selected one or set of the plurality of engaging points with the first engaging unit or second engaging unit wherein the locking arrangement comprises a locking member disposed between the lower arms. 2. The grass mower according to claim 1, wherein the at least one locking arrangement is disposed adjacent to or along an axis of symmetry of the lower frame. 3. The grass mower according to claim 1, wherein the lower frame comprises a pair of substantially parallel lower arms extending rearwardly from the main body, wherein the upper frame comprises a pair of substantially parallel upper arms and a closed operator grip for the operator to hold. 4. The grass mower according to claim 1, further comprising: a first bracket mechanism mounted on the first joint portion; and a second bracket mechanism mounted on the second joint portion wherein the first engaging unit is mounted in the first bracket mechanism and the second engaging unit is mounted in the second bracket mechanism. 5. The grass mower according to claim 4, wherein the first engaging unit is a tooth member and the second engaging unit is a movable tooth member, wherein the teeth of the tooth member are selectively meshable with more than one selected one or set of the teeth of the movable tooth member. 6. The grass mower according to claim 5, wherein the first bracket mechanism comprises an upper cover plate and a lower cover plate, wherein the tooth member is seated in a cavity on the upper cover plate, wherein the upper cover plate has a pair of substantially parallel spaced-apart, substantially semi-circular axial slots and the lower cover plate has a pair of substantially parallel spaced-apart, substantially semi-circular axial slots whereby the pair of substantially parallel lower arms are captured between the substantially parallel spaced-apart, substantially semi-circular axial slots of the upper cover plate and the substantially parallel spaced-apart, substantially semi-circular axial slots of the lower cover plate. 7. The grass mower according to claim 6, wherein the upper cover plate is mounted radially on the elongate shaft and the first bracket mechanism and the second bracket mechanism are pivotal about the elongate shaft. 8. The grass mower according to claim 5, wherein the tooth member has six teeth disposed along an arc around an axis of the elongate shaft. 9. The grass mower according to claim 5, wherein the second bracket mechanism comprises an upper cover plate and a lower cover plate wherein the movable tooth member is seated in a cavity in the upper cover plate, wherein the upper cover plate has a pair of substantially parallel spaced-apart, substantially semi-circular axial slots and the lower cover plate has a pair of substantially parallel spaced-apart, substantially semi-circular axial slots whereby the pair of substantially parallel upper arms are captured between the substantially parallel spaced-apart, substantially semi-circular axial slots of the upper cover plate and the substantially parallel spaced-apart, substantially semi-circular axial slots of the lower cover plate. 10. The grass mower according to claim 5, wherein the movable tooth member has three teeth disposed along an arc around an axis of the elongate shaft. 11. The grass mower according to claim 5, wherein the at least one locking arrangement comprises: an axial spindle with a first end and a second end; and a cam locking member connected to the second end of the axial spindle, wherein the movable tooth member has a central bore for receiving the first end of the axial spindle. 12. The grass mower according to claim 11, wherein the locking arrangement further comprises: a biasing element with a tendency to bias the movable tooth member into disengagement with the tooth member, wherein when the cam locking member is released the biasing element biases the movable tooth member into disengagement with the tooth member. 13. The grass mower according to claim 10, wherein the locking arrangement is a manually retractable locking member which is threadedly fastened to the movable tooth member. 14. The grass mower according to claim 13, wherein the locking arrangement further comprises: a biasing element with a tendency to bias the movable tooth member into engagement with the tooth member, wherein when the retractable locking member is retracted the biasing element releases the movable tooth member into disengagement from the tooth member. 15. The grass mower according to claim 2, wherein the first engaging unit is a first pair of gears mounted on the outer face of the first joint portion and the second engaging unit is a second pair of gears mounted radially on the second joint portion, wherein either the first pair of gears is equipped with a plurality of engaging points which is disposed along an arc around the elongate shaft and the second pair of gears (51) is selectively engageable with more than one selected one or set of the plurality of engaging points, or the second pair of gears is equipped with a plurality of engaging points C3') which is disposed along an arc around the elongate shaft, wherein the first pair of gears is selectively engageable with more than one selected one or set of the plurality of engaging points. 16. The grass mower according to claim 15, wherein the first and second pairs of gears and the joint portions are mounted radially on the elongate shaft, wherein the locking arrangement is a cam locking member (2')coupled to a first end of the elongate shaft. 17. The grass mower according to claim 1, wherein the lower frame is a single arm connected to the main body at a proximal end and has a first joint portion disposed at the distal end, wherein the upper frame is a single arm which has an operating handle grip at a distal end and has a second joint portion being a fork at a proximal end. 18. The grass mower according to claim 17, wherein the first engaging unit is a first pair of gears mounted respectively on the outer face of the first joint portion and the second engaging unit is a second pair of gears mounted respectively on the inner face of the fork of the second joint portion wherein either the first pair of gears (66) is equipped with a plurality of engaging points which is disposed along an arc around the elongate shaft and the second pair of gears is selectively engageable with more than one selected one or set of the plurality of engaging points, or the second pair of gears is equipped with a plurality of engaging points which is disposed along an arc around the elongate shaft (68), wherein the first pair of gears is selectively engageable with more than one selected one or set of the plurality of engaging points. 19. A grass mower according to claim 2, wherein the axis of symmetry is a longitudinal axis of symmetry between the pair of arms of the lower frame and the locking member is positioned on the axis of symmetry.