Conveyors: power-driven – Conveyor having impinging fluid to feed – shift or discharge... – Having cleaning means
Reexamination Certificate
1998-10-02
2001-11-27
Hess, Douglas (Department: 2167)
Conveyors: power-driven
Conveyor having impinging fluid to feed, shift or discharge...
Having cleaning means
C198S496000
Reexamination Certificate
active
06321900
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the deriving of hydraulic power from the linear or rotary motion of an endless conveyor belt or the linear or rotary motion of other components or devices fitted to an endless conveyor belt, said conveyor being of the type having an upper conveyor run and a lower return run.
BACKGROUND AND GENERAL DESCRIPTION OF THE INVENTION
According to one aspect of the invention, there is provided a power take off device for an endless conveyor belt system of the type comprising an endless belt having an upper conveyor run for transporting material and a lower return run, the power take off device comprising an hydraulic pump operably linked to the belt or to a rotating component forming part of the conveyor belt system so as to generate hydraulic fluid at pressure only when the conveyor belt is in motion.
In another aspect, the invention provides a conveyor belt system incorporating a power take off device as defined above.
For convenience hereinafter an endless conveyor system will be referred to as a conveyor belt, or a conveyor belt system.
An existing roller or drum in the conveyor belt system can be utilised to provide rotary motion to drive an hydraulic pump, or a roller can be introduced into the conveyor belt system to achieve the required drive to the pump. The existing roller or the drive obtained from other components, or the introduced roller, becomes an automatically interlocked prime mover to rotate an hydraulic pump. Fluid pressure from the pump may then be used to power hydraulic actuators. Electrical motors, switchgear and interlocking supply would not be required.
Specifically the pump may be used to transmit a volume of fluid at pressure to a number of devices used on conveyor belts. These include belt scrapers, drum scrapers, top and bottom belt ploughs, rotary brush cleaners and fines conveyors.
In all these devices, as they are used, wear takes place and regular adjustments is required. Belt cleaning devices they need to be maintained in contact with the belt surface to ensure that efficient cleaning is taking place. By providing hydraulic fluid at pressure to actuators the cleaners can be maintained at constant pressure against the belt surface thereby providing a self adjusting mechanism at a pre-determined constant force which will require no adjustment throughout the cleaning elements' life.
The power take off of the invention is of particular utility for the automatic tensioning of belt cleaning devices, especially belt scrapers.
The hydraulic pump may have an internal or external relief valve, internal or external flow control, and an internal or external reservoir, or may be a pump that is contained within a roller, the inside of the roller being used as the reservoir. A support or bracket may fix the hydraulic pump to the conveyor framework and contain any torque reaction.
A driving roller may be introduced into the conveyor system to frictionally engage with any surface or edge of the belt fabric, or drums, to produce rotary motion or linear motion with which to rotate or otherwise drive the pump. Alternatively a stub shaft or drive train may be used to derive the necessary motion to the pump from existing roller, drums, or other rotary components within the endless belt system, or from any other components or equipment retrofitted to operate on the conveyor belt system. In another embodiment a roller may be introduced into the system which when the belt is not loaded with material is disengaged and frictional engagement takes place when the weight of the material being transported depresses the belt to rotate the pump roller.
The pump may be connected to the rotary motion or linear motion of the endless belt system by any suitable means, eg freewheel clutch, flexible drive cable, magnetic coupling or drive train. Rotary or linear actuators which are supplied with fluid pressure via hoses or pipes may be single or double acting.
The generating pump can take any suitable form, eg piston, gear, vane, centrifugal or diaphragm to generate the required hydraulic flow and pressure. Alternatively an existing pump may be used to provide the pressure such as a lubrication pump inside a gearbox. The pressure may be obtained by utilising the pressure generated by a scoop type traction coupling, to maintain constant pressure via a pressure reducing valve to belt cleaning equipment or any equipment that needs to be continually adjusted. The hydraulic fluid can be of any type or viscosity, eg mineral or vegetable oil, synthetic oil, soluble oil, water, detergent, cleaning fluid or disinfectant.
The device is fixed to any suitable of the conveyor by any suitable means and may be portable and attached to any suitable structure anywhere along its run to provide hydraulic pressure to operate pumps and hand tools, or to spray fluid onto the belt to clean or sterilise the belt.
The pump may be used to detect slowing down of the belt ie belt slip or overloading, whereby a pressure drop causes the power to be removed from the conveyor drive by the used of a pressure switch. The pressure generated may be used to maintain constant pressure to a belt scraper/cleaner and also to operate a vibrator attached to the scraper/cleaner to induce vibration forces into a localised area of the belt surface.
The power take off device may generate hydraulic fluid at pressure to more than one item of equipment by the use of unloading valves, direction valve, pressure reducing valves and the like. The power take off device may convert the rotary motion of the conveyor belt or other components within the conveyor system, or retrofitted to the conveyor system, into linear motion to drive an hydraulic pump that operates by linear motion.
The hydraulic fluid generated may power an automatic lubrication system to grease or oil at desired intervals, bearings and other moving components within and around the conveyor belt system.
The pump may be a tandem or triple pump within the same housing and driven from one source, producing fluid at pressure at different settings to operate more than one circuit.
The power take off device may provide hydraulic pressure to any number of belt cleaning devices.
The hydraulic pressure to the actuators may be removed when a joint in the belt is approaching allowing the cleaning device to relax from the belt and the joint to pass over the cleaner unhindered. Pressure would then be reapplied after the joint or obstruction has passed.
A pump may be fitted at each end of the conveyor and between drive input and pump a freewheel clutch may be fitted to ensure that pressure is only generated in one direction.
Fines conveyors are fitted underneath the drivehead of an endless conveyor to transfer spillage and debris removed from the belt surface by the aforementioned belt cleaners. These are usually of the type that has an endless chain with flight bars running in a race within the conveyor pan to convey material into the main chute along with the main flow of material. These chains stretch and wear takes place between the links. This slack chain needs to be continually adjusted to avoid the links standing on end and jamming in the return race. By fitting linear actuators at one end of the chain conveyor, with pressure being provided from a pump attached to the conveyor belt system, the slack chain could be continually adjusted at a predetermined force therefore negating any manual adjustment until the chain is worn or stretched beyond practical use.
The aforementioned uses only require the hydraulic power when the conveyor belt is in motion, once the conveyor belt has stopped the pressure in the hydraulic circuit reduces, relaxing the device it is operating. In most cases this would not be detrimental and probably advantageous as components in the system would not be under load when the conveyor belt is stationary. This relaxing of the component being operated would dislodge any material built up around the operating mechanism and not allow cylinders to stick in a position. Should it be required to maintain pressure in the
Hess Douglas
Jones Tullar & Cooper P.C.
Scorpio Conveyor Products (Proprietary) Limited
LandOfFree
Power take off from an endless conveyor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Power take off from an endless conveyor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Power take off from an endless conveyor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2600084