Clutch and brake controls for clamshell hoist

Claim 2

A hoist assembly and associated control for a hoist machine comprising: a closing drum having first brake means, a holding drum having second brake means, power transmitting means connecting the closing drum and the holding drum whereby said drums rotate at substantially the same speed, a shaft connected to the power transmitting means, said closing drum being rotatably mounted on said shaft, a pair of clutches drivably coupling the closing drum with the shaft, power disconnecting means for controlling power input to the power transmitting means, and fluid pressure control means for said first brake means, said second brake means, and said power disconnecting means, said control means having a closing drum clutch, valve means operable to actuate said clutches, and means operable to simultaneously actuate both said first and second brake means and release the power disconnecting means so that the holding drum is under the control of both the first brake means and the second brake means, said power disconnecting means is a master clutch means having the control means coupled to the closing drum clutch valve means, said control means is operable to actuate the master clutch before actuation of the closing drum clutches.

Claim 3

The structure of claim 1 wherein: said first brake means comprise a pair of brakes for braking the closing drum.

Claim 4

The structure of claim 1 wherein: said first brake means comprise a pair of brakes and said second brake means comprise a pair of brakes.

Claim 5

The structure of claim 1 wherein: said shaft means includes a first shaft rotatably carrying the closing drum, a second shaft rotatably carrying the holding drum, closing clutch means coupling said first shaft with the closing drum, and holding clutch means coupling the second shaft with the holding drum, said power transmitting means connecting the first shaft with the second shaft.

Claim 6

The structure of claim 4 wherein: said power transmitting means includes a gear train connecting the first shaft with the second shaft.

Claim 7

The structure of claim 1 wherein: the power disconnecting means includes a torque converter located between the power source and the power transmitting means.

Claim 8

The structure of claim 6 wherein: the master clutch is between the power source and the torque converter.

Claim 9

A hoist assembly and associated control for a hoist machine comprising: a closing drum having first brake means, a holding drum having second brake means, power transmitting means connecting the closing drum and the holding drum whereby said drums rotate at substantially the same speed, a first shaft rotatably carrying the closing drum, closing clutch means coupling said first shaft with the closing drum, a second shaft rotatably carrying the holding drum, holding clutch means coupling the second shaft with the holding drum, said power transmitting means connecting the first shaft with the second shaft, power disconnecting means for controlling power input to the power transmitting means, and fluid pressure control means for said first brake means, said second brake means and said power disconnecting means, said fluid pressure control means including means operable to simultaneously actuate both of said first and second brake means and release the power disconnecting means so that the holding drum is under the control of both the first brake means and the second brake means, said means of the fluid pressure control means comprising a closing clutch control, a holding clutch control, a power disconnecting means control coupled to the closing control and the holding clutch control and operable to actuate the power disconnecting means before actuation of either the closing clutch or the holding clutch.

Claim 10

A hoist assembly and associated control for a hoist machine comprising: a closing drum having first brake means, a holding drum having second brake means, power transmitting means connecting the closing drum and the holding drum whereby said drums rotate at substantially the same speed, a first shaft rotatably carrying the closing drum, closing clutch means coupling said first shaft with the closing drum, a second shaft rotatably carrying the holding drum, holding clutch means coupling the second shaft with the holding drum, said power transmitting means connecting the first shaft with the second shaft, power disconnecting means for controlling power input to the power transmitting means, and fluid pressure control means for said first brake means, said second brake means and said power disconnecting means, said fluid pressure control means including means operable to simultaneously actuate both of said first and second brake means and release the power disconnecting means so that the holding drum is under the control of both the first brake means and the second brake means, said means of the fluid pressure control means comprising a closing clutch control, a holding clutch control, a power disconnecting means control coupled to the closing control and the holding clutch control and operable to actuate the power disconnecting means before actuation of either the closing clutch or the holding clutch.

Claim 11

The structure of claim 8 wherein: said first brake means comprise a pair of brakes and said second brake means comprise a pair of brakes.

Claim 12

The structure of claim 8 wherein: the power disconnecting means includes a master clutch and torque converter located between the power source and power transmitting means.

Claim 13

The structure of claim 10 wherein: the master clutch is between the power source and torque converter.

Claim 14

A hoist assembly and associated control for a hoist machine comprising: a closing drum having first brake means, a holding drum having second brake means, power transmitting means connecting the closing drum and the holding drum whereby said drums rotate at substantially the same speed, power disconnecting means for controlling power input to the power transmitting means, and fluid pressure control means for said first brake means, said second brake means and said power disconnecting means, said fluid pressure control means including means operable to simultaneously actuate both of said first and second brake means and release the power disconnecting means so that the closing drum and holding drum are under the control of both the first brake means and the second brake means, said means of the fluid pressure control means for the first brake means and second brake means comprising a holding brake valve for directing fluid under pressure to the second brake means and to a pilot valve operable to permit fluid under pressure to flow from the holding brake valve to the first brake means, a closing valve operable to provide fluid under pressure to release the power disconnecting means and to actuate the pilot valve whereby the first brake means and second brake means are both controlled by the operation of the holding brake valve.

Claim 15

A hoist assembly and associated control for a hoist machine comprising: a closing drum having first brake means, a holding drum having second brake means, power transmitting means connecting the closing drum and the holding drum whereby said drums rotate at substantially the same speed, power disconnecting means for controlling power input to the power transmitting means, and fluid pressure control means for said first brake means, said second brake means and said power disconnecting means, said fluid pressure control means including means operable to simultaneously actuate both of said first and second brake means and release the power disconnecting means so that the closing drum and holding drum are under the control of both the first brake means and the second brake means, said means of the fluid pressure control means for the first brake means and second brake means comprising a holding brake valve for directing fluid under pressure to the second brake means and to a pilot valve operable to permit fluid under pressure to flow from the holding brake valve to the first brake means, a closing valve operable to provide fluid under pressure to release the power disconnecting means and to actuate the pilot valve whereby the first brake means and second brake means are both controlled by the operation of the holding brake valve.

Claim 16

The structure of claim 12 wherein: the power transmitting means has a first clutch means coupled to the closing drum and a second clutch means coupled to the holding drum, said closing valve also operable to provide fluid under pressure to actuate both the first clutch means and the second clutch means whereby the closing drum and holding drum are drivably coupled together.

Claim 17

The structure of claim 12 wherein: the first brake means comprise a pair of brakes for braking the closing drum.

Claim 18

The structure of claim 12 including: shaft means connected to the power transmitting means, said closing drum being rotatably mounted on said shaft means, and a pair of clutches drivably coupling the closing drum with the shaft means, said control means having a closing drum clutch and valve means operable to actuate said pair of clutches.

Claim 19

The structure of claim 15 wherein: said shaft means includes a first shaft rotatably carrying the closing drum and a second shaft rotatably carrying the holding drum.

Claim 20

The structure of claim 16 wherein: said power transmitting means includes a gear train connecting the first shaft with the second shaft.

Claim 21

The structure of claim 12 wherein: the power disconnecting means includes a master clutch and torque converter located between the power source and the power transmitting means.