초록 ▼

A braking system is provided for a construction machine, including a ground engaging drive apparatus. The construction machine includes a hydraulic drive system, including a hydraulic motor connected to the ground engaging drive apparatus and a first hydraulic pump for supplying fluid under pressure

A braking system is provided for a construction machine, including a ground engaging drive apparatus. The construction machine includes a hydraulic drive system, including a hydraulic motor connected to the ground engaging drive apparatus and a first hydraulic pump for supplying fluid under pressure to the motor, the pump and motor being connected so that a braking force may be applied to the drive apparatus by varying the discharge volume of the first pump. A first valve is connected between an inlet and an outlet of the first pump for shunting the pump. An emergency brake is connected to the ground engaging drive apparatus, and is mechanically biased in a brake applying direction. A second hydraulic pump supplies fluid to a hydraulic actuator for releasing the emergency brake. A second valve is located between the second pump and the hydraulic actuating means. A common actuator is connected to the first and second valves and is variable between a first position wherein the first valve is closed and the second valve is open, and a second position wherein the first valve is open and the second valve is closed. A sensor detects movement of the common actuating actuator between the first and second positions, and causes fluid pressure to be relieved from the hydraulic actuator so that the emergency brake is applied before the second valve is closed. Downstream of the second valve is an auxiliary pump for supplying pressure to release the emergency brake when the common actuating handle is in its second position.

대표청구항 ▼

A braking system for a construction machine, comprising: a ground engaging drive means; a hydraulic drive system, including a hydraulic motor connected to said ground engaging drive means and a hydraulic pump for supplying fluid under pressure to said motor, said hydraulic drive system being constru

A braking system for a construction machine, comprising: a ground engaging drive means; a hydraulic drive system, including a hydraulic motor connected to said ground engaging drive means and a hydraulic pump for supplying fluid under pressure to said motor, said hydraulic drive system being constructed so that said drive means may be braked by varying the discharge volume of the hydraulic pump; an emergency brake, biased to apply a braking force to said ground engaging drive means; a means for shunting said hydraulic pump, said shunting means including a first valve, variable between a first position isolating an inlet and an outlet port of said pump and a second position connecting said inlet and outlet ports to shunt said pump; a means for releasing said emergency brake; a common actuating means, connected to said shunting means and releasing means, said actuating means being movable between a first position, wherein said hydraulic pump supplies fluid to drive said motor and said releasing means is actuated to release said emergency brake and a second position, wherein said hydraulic pump is shunted and said releasing means is deactivated so that said emergency brake acts to retard the motion of said ground engaging drive means.