GB2175360A - Mower with locking differential - Google Patents

Abstract

A pedestrian guided mower has two driven wheels on a common axis with a differential mechanism in conventional manner for ease of manoevreing the mower. A shaft 24 parallel to the axle half-shafts provided with pinions 26 to mesh with complementary pinion 20 fast with the half shafts. When so meshed the differential is rendered ineffective and the arrangement is the same as if there were a solid axle connecting the wheels. The shaft 24 can be displaced bodily to disengage the pinions 26 allowing the differential to be effective when required, under the action of a pedal 40. <IMAGE>

Description

SPECIFICATION Mower This invention relates to mowers primarily but not exclusively intended for pedestrian guidance and having a pair of ground engaging driven wheels, on a common axis for propulsion of the mower. For convenience of manoeuvring it is normal to use a differential mechanism in the axle casing, but this creates problems on unlevel ground particularly if the mower is being used to cut in straight lines traversing steep banks.

According to the invention, a mower of the kind comprising a pair of driven wheels on a common axis, with a differential mechanism in the drive train to the respective wheels, is characterised by the provision of a differential lock which can be engaged to cut out the differential.

Preferably each of the wheels is provided with a hub fast to a common half shaft driven from the differential, and each of the half shafts is provided with an exposed gear pinion or sprocket, and a shaft parallel with said half shafts has complimentary pinions or sprockets fast therewith, means being provided for moving the parallel shaft to mesh all of the pinions or sprockets thereby making the differential ineffective.

An embodiment of the invention is now described with reference to the accompanying drawings in which: Figure 1 is a side elevation; and Figure 2 is a plan.

Referring to the drawings, which show a portion of the chassis of a mower only, with the actual cutting cylinder or flail shaft, the engine and drive transmission all omitted for clarity. The mower essentially comprises a pair of drive wheels 10 12 mounted on a common axle housing 14 including a differential unit 16. Each wheel hub 18 carries, in this embodiment, a chain sprocket 20 which is fast with the hub which in turn is keyed to the corresponding half shaft.

A parallel shaft 24 is provided mounting a pair of pinions 26 having a periphery designed to mesh with the chain sprockets 20. For example, each pinion 26 may consist of a drum having an encircling length of roller chain fixed to the drum, with the drums fixed to the shaft. The shaft is journalled in suitable bearing in a pair of swinging links 28 pivoted at 30 to the chassis 32. The links are connected by an operating rod 34 to a bell crank 36 also pivoted to the chassis 38 and with an operating pedal 40 fast with the crank.

In the broken line position the pinions are disengaged from the sprockets and the differential is fully effective. In the full line position the pinions are meshed with the sprockets and because those pinions are fast with the shaft 24, the differential is rendered ineffective and effectively locked up.

1. A mower comprising a pair of driven wheels on a common axis, with a differential mechanism in the drive train to the respective wheels, characterised by the provision of a differential lock which can be engaged to render the differential ineffective.

2. A mower as claimed in Claim 1 wherein each of the wheels is provided with a hub fast to a common half shaft driven from the differential, and each of the half shafts is provided with an exposed gear pinion or sprocket, a shaft parallel with said half shafts having complementary pinions or sprockets fast therewith, and means for moving the parallel shaft to mesh all of the pinions or sprockets.

3. A mower substantially as described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Mower This invention relates to mowers primarily but not exclusively intended for pedestrian guidance and having a pair of ground engaging driven wheels, on a common axis for propulsion of the mower. For convenience of manoeuvring it is normal to use a differential mechanism in the axle casing, but this creates problems on unlevel ground particularly if the mower is being used to cut in straight lines traversing steep banks. According to the invention, a mower of the kind comprising a pair of driven wheels on a common axis, with a differential mechanism in the drive train to the respective wheels, is characterised by the provision of a differential lock which can be engaged to cut out the differential. Preferably each of the wheels is provided with a hub fast to a common half shaft driven from the differential, and each of the half shafts is provided with an exposed gear pinion or sprocket, and a shaft parallel with said half shafts has complimentary pinions or sprockets fast therewith, means being provided for moving the parallel shaft to mesh all of the pinions or sprockets thereby making the differential ineffective. An embodiment of the invention is now described with reference to the accompanying drawings in which: Figure 1 is a side elevation; and Figure 2 is a plan. Referring to the drawings, which show a portion of the chassis of a mower only, with the actual cutting cylinder or flail shaft, the engine and drive transmission all omitted for clarity. The mower essentially comprises a pair of drive wheels 10 12 mounted on a common axle housing 14 including a differential unit 16. Each wheel hub 18 carries, in this embodiment, a chain sprocket 20 which is fast with the hub which in turn is keyed to the corresponding half shaft. A parallel shaft 24 is provided mounting a pair of pinions 26 having a periphery designed to mesh with the chain sprockets 20. For example, each pinion 26 may consist of a drum having an encircling length of roller chain fixed to the drum, with the drums fixed to the shaft. The shaft is journalled in suitable bearing in a pair of swinging links 28 pivoted at 30 to the chassis 32. The links are connected by an operating rod 34 to a bell crank 36 also pivoted to the chassis 38 and with an operating pedal 40 fast with the crank. In the broken line position the pinions are disengaged from the sprockets and the differential is fully effective. In the full line position the pinions are meshed with the sprockets and because those pinions are fast with the shaft 24, the differential is rendered ineffective and effectively locked up. CLAIMS

1. A mower comprising a pair of driven wheels on a common axis, with a differential mechanism in the drive train to the respective wheels, characterised by the provision of a differential lock which can be engaged to render the differential ineffective.

2. A mower as claimed in Claim 1 wherein each of the wheels is provided with a hub fast to a common half shaft driven from the differential, and each of the half shafts is provided with an exposed gear pinion or sprocket, a shaft parallel with said half shafts having complementary pinions or sprockets fast therewith, and means for moving the parallel shaft to mesh all of the pinions or sprockets.

3. A mower substantially as described with reference to the accompanying drawings.