AU2003200280B2

AU2003200280B2 - Hatch Opening Mechanism

Info

Publication number: AU2003200280B2
Application number: AU2003200280A
Authority: AU
Inventors: Brian Thomas
Original assignee: UNITED GROUP RAIL SERVICES Ltd
Current assignee: UNITED GROUP RAIL SERVICES Ltd
Priority date: 2002-01-30
Filing date: 2003-01-30
Publication date: 2009-05-14
Anticipated expiration: 2023-01-30
Also published as: AU2003200280A1

Description

AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: Hatch Opening Mechanism The following statement is a full description of this invention, including the best method of performing it known to :- us 1 HATCH OPENING MECHANISM FIELD OF THE INVENTION The invention relates to mechanisms used to operate closures in vehicles used in the bulk transport of particulate matter, such as grain, coal and the like, 5 and in particular mechanisms used to open and close hatches. The invention is particularly applicable to top end loaded railway carriages used for the bulk handling of grain, coal and the like. BACKGROUND OF THE INVENTION The bulk transport of particulate matter, specifically grain, coal and other 10 particulate materials, over land is usually accomplished using dedicated railway carriages, in particular top end loaded railway carriages. The top wall of such carriages is provided with one or more openings for bulk filling of the carriage interior. The openings are closed by hatches which are hinged to allow them to come to rest horizontally on the top wall when in the open position and otherwise 15 cover the opening. To avoid the need for personnel having to manually open each hatch, which requires the operator to work at elevated heights, it is conceivable to employ remote hatch actuating mechanisms to pivot the hatch between the open and closed positions. This would entail the use of servos or other actuator motors located close to and mechanically coupled to the hatches. 20 The bulk filling operation itself creates particularly invasive dust within the carriage hold which affects seals and bearings of any equipment located within the carriage or exposed to dusting during the filling operation. Normally, frequent maintenance is required to prevent seizing and general failure of such equipment. It would be advantageous, therefore, to provide a mechanism that allows 25 remote opening and closing of hatches using a simple mechanism with as few components as possible, enabling simple and safe operation, and high reliability. It would be equally advantageous to reduce the number of individual drives required to operate a plurality of hatches simultaneously. STATEMENT OF THE INVENTION 30 The invention provides an opening mechanism for a hatch, including a rotatable shaft to which the hatch is secured such as to rotate therewith and about which the hatch opens, a linear actuator having a ram capable of selective extension from or withdrawal into an actuator body on actuation, said ram 2 pivotally mounted to an offset cam which in turn is rotationally fixed to the shaft, and a swing arm pivotally mounted to an external fixture or fixity at a first end and to the linear actuator at an opposed second end the external fixture further including limitation means to limit rotation of the swing arm to a predetermined 5 angle of rotation between a first and second limit, wherein the mechanism is arranged such that on actuation the swing arm is either rotated to the first limit, thereby permitting the actuator to impart a torque to the shaft to open the hatch, or the swing arm is rotated to the second limit, thereby permitting the actuator to impart a torque to the shaft to close the hatch. 10 With simplicity and limited required maintenance being an objective of the invention, the invention achieves these through a simple arrangement of the linkage members and use of a linear actuator, such as a pneumatic or hydraulic ram. By activating the actuator, the ram may extend or contract, and cause the cam to rotate. The swing arm provides a moveable reaction point for the 15 actuator, such that the position of the actuator can shift so as to bias the cam on opposing sides of the cam's point of rotation. The point of rotation of the cam is defined by the axis of the rotatable beam, which the hatch is bound to, and thus the hatch may be opened by a simple operation of the actuator through approximately 1800 by means of the simple arm linkage arrangement. 20 In a preferred embodiment, the angle of rotation of the swing arm is less than 180*. If desired, the linkage arm arrangement, in particular stop elements intended to restrict the rotational path of motion of the swing arm, can be modified where the hatch open position is less or more than 1800 rotationally offset to the 25 hatch closed position, e.g. a 90* travel path between hatch open and closed positions. The external fixture may be a fixed portion of a vehicle or container for which the hatch serves as a closure member. An example may be a pedestal or purpose built sub-structure. 30 The pedestal which supports the link arms can incorporate the stop elements which prevent physically the swing arm from free, unrestricted rotation about its pivot point at the pedestal.

3 The pedestal may itself be a structure that can be connected to a range of structures within the freight wagon, with the only restriction that there is sufficient integrity to the structure to transmit the required loads of opening the hatch, and that the pedestal is fixed relative to the walls or floor of the bulk carrier wagon. 5 Thus, the invention is a mechanical system, which may be powered by a single actuator, either hydraulically or pneumatically operated, but preferably pneumatic. The actuator controls may be simple to operate, as the operation is limited to an extension/contraction movement of the ram rod, and may be mounted at 10 headstock level on diagonally opposite corners of the grain carrying wagon. At one end of the wagon, the off-set cam may be rigidly connected to the rotatable beam. This cam provides the interface for the actuator. The invention permits the use of a single actuator to be used which is advantageously positioned at one end of the wagon. Ram actuators may equally 15 be located at both ends of the wagon for increased torque transmission where necessary. A single actuator, in conjunction with the stops and linkage (swivel) arm connecting the actuator (ie drive unit) to the rotatable beam to which the hatch(es) is (are) secured, serves to lift the hatches upwards from the fully closed 20 and fully open (horizontal) positions and to control the ascent and decent of the hatches. The actuator itself may also serve to keep the hatch closed during track running of the freight wagon, thereby dispensing with the need for conventional latches or similar mechanisms previously employed to secure freight wagon hatches. 25 The swing arm may be connected to the end wall of the wagon or to the shear plate via a pedestal. This pedestal provides the pivoted connection. The actuator is connected to the swing arm. The extent of swing is controlled by means of stops which are connected rigidly to the pedestal. Thus, in a preferred embodiment, the hatch operating mechanism of the 30 type just described may be retrofitted on existing wagon stock, and is adaptable to suit all grain wagon types. The use of the inventive mechanism has the potential to reduce the amount of spare parts required across a fleet of such wagons. The invention may provide the following benefits: 4 * Adaptable to all types of wagon e Achieves up to 1800 of controlled hatch rotation e Utilises existing hatches thus permitting costs to be minimized (new covers can easily be used if required) 5 e Fits under all freight wagon top loading facilities e Uses a minimum of moving components 0 May require only one actuator per wagon e Provides a low mass solution e Requires only one push button for all operations (ie does not require 10 one for opening and another for closing) * Requires a minimum of control valves e Provides high reliability through minimising the number of components and through selecting proven products e Permits easy installation onto existing wagons with a minimum of 15 connections * The control boxes form line replaceable units (LRU's) for fast interchange e Robust quick-fit connectors are used throughout DESCRIPTION OF PREFERRED EMBODIMENT 20 It will be convenient to further describe the present invention with respect to the accompanying drawings, which illustrate possible arrangements of the invention. Other arrangements of the invention are possible and, consequently, the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention. 25 BRIEF DESCRIPTION OF DRAWINGS Figure 1 is a perspective view of a hatch opening mechanism embodiment according to the present invention; Figures 2A to 2H are elevation views of the hatch opening mechanism of Figure 1 illustrating the sequence of hatch opening and closing. 30 Figure 1 shows the opening mechanism (1) of one embodiment of the present invention, powered by a single pneumatic actuator ram (4). The opening mechanism (1) comprises a single swing arm, or link (6), pivoted at the base of 5 the actuator (4) and a cam (5) connected to a rotatable beam, in this case the hatch shaft (9). The swing arm (6) is pivoted at a pedestal (7) secured to the end wall of a bulk material freight wagon (not shown). A compression spring (not shown) may additionally be used to guarantee the correct positioning of the swing 5 link (6) during some stages of movement thereof. The swing link (6) and cam (5) transform the linear motion of the actuator (4) into a controlled rotation of the hatch shaft (9) fixed to the top of the wagon (3). This shaft (9) is fixed to at least one, and preferably several top hatches (2) in series on the vehicle and is supported via a number of bearings about which 10 the shaft (9) rotates. When operated, all hatch doors open and close simultaneously. Mounting of the hatch shaft (9) inside the wagon, together with its actuating mechanism, has been selected to minimise deflection and torsional twist due to the hatch loads, whilst also ensuring wagon height is as low as 15 possible. All mechanical components, including shaft bearing housings and mounting bracketry, may be attached to existing structures within the wagon using fastener bolts. This provides a permanent connection without the concerns associated with welding to an aluminium structure. 20 Figures 2A to 2E show sequentially, the opening of the hatch (2) on actuation of the actuator (4). The concept operates using the concept of an "unbalanced" actuator which acts to lift the hatch upwards and over the centre of the pivot beam (9) in a controlled manner. This entails locating the axis of rotation of the swing link arm (6) at its pedestal mounting (7) and the axis of rotation of the 25 cam member (5) fixed on the pivot beam (9) of the hatch in vertical alignment, such that the actuator ram (4) which is pivoted between the cam member (5) and the swing link arm (6) is free to rotate upon displacement of the ram rod whilst the link arm (6) abuts against rotation restricting stops (8A, 8B) provided at the pedestal (7), as will become clearer from the below description of the kinematics 30 of operation. OPENING AND CLOSING OPERATION The initial condition of the equipment has the hatch (2) in its closed position and the actuator (4) in its fully retracted condition. The swing link (6) 6 (that is the line connecting its two pivot points where it engages the pedestal mounting and the actuator ram) is located in a straight line with the ram actuator's centre line (or rod travel axis) although the longitudinal axis of the ram itself is inclined with respect to the vertical. 5 As air pressure is applied to the actuator (4), the actuator rod (10) pushes the swing link (6) anti-clockwise down to its rest or stop position at which point swing arm (6) hits its stop (8B) at the pedestal mounting. The stop (8B) now reacts the force of the actuator (4) as it continues operation. As the force from the actuator continues to increase, the actuator rod (10) 10 transmits this and generates a torque (11) to rotate hatch beam (9) via the off-set cam (5). This torque acts to open the hatches (2). The actuator rod (10) continues to telescope or extend whilst simultaneously rotating the hatches until it reaches a fully extended or "neutral" position. This neutral position is determined by the alignment of the pivot centres 15 of the beam (9) and those at the ram actuator (top and bottom pivots for the swing arm (6) and cam (5). At this position the centre of gravity of the hatches has passed over the centre line (ie axis of rotation) of the beam (9), causing the hatch (2) to move (12) unaided to the fully open horizontal position whilst the ram actuator (4) itself 20 rotates about its pivot connection with the sing arm (6). The mass of the hatches plus the reduction in actuator force will permit the hatches to lower (12) into the open position. The air pressure to the cylinder can then be removed thus removing the actuator extension force. The air pressure can then be applied to retract the 25 actuator rod (10) into the ram cylinder to initiate a hatch closing operation. When the hatches (2) are in the open position (horizontal), the actuator rod (10) is able to contract into the ram cylinder, thereby swinging arm (6) about its pivot connection at the pedestal and thus "pulling" the swing arm (6) upwards (13) out of its stop position and over the centre alignment position into a rotational 30 state where extending of the ram rod (10) will cause the link arm (6) to continue a clockwise rotation about its pivot connection at the pedestal until it reaches abutment at stop (8A). Once this position is attained, further rotation of arm (6) is prevented and the actuator ram force upon further extension of the actuator rod 7 (10) is reacted at the pedestal, enabling the hatches to be rotated out of the open toward their closed position in a manner similar to that described in connection with the opening operation but in opposite direction, compare figures 2F to 2H. PNEUMATIC SYSTEM 5 A conventional pneumatic system is used to operate the linear actuator; its lay-out and associated control circuitry being well known and thus not described nor illustrated here. The pneumatic drive used in the hatch opening process is supplied with compressed air from the wagon's existing reservoir. The pneumatic controls may advantageously be located within a box which 10 can be mounted onto the shear plates on any diagonal corner of the wagon. The box is ideally accessible from track side. The top hatches can be operated (opening and closing cycles) from either the control box of an individual wagon or, if desired using a central control box wired to control individual carriage controls. MAINTENANCE 15 By providing a design with reduced number of components and specific arrangement of components, the mechanism according to the invention is maintenance friendly and enables safe, remote operation of the hatches by personnel entrusted with filling and emptying freight bulk carrier wagons. The mechanism is further arranged such that the only component likely to require 20 maintenance, ie the pneumatic ram actuator, can be easily decoupled from its pivot fastening points, removed and replaced, enabling the installation of spare parts whilst original parts are undergoing routine inspection and maintenance. It will be appreciated that such hatch opening mechanism may be employed in other type of granular or liquid freight carrier wagons that are loaded 25 from the top and where it is desired to avoid the need for personnel to climb on such wagons and manually open and close the hatches.

Claims

1. An opening mechanism for a hatch, including a rotatable shaft to which the hatch is secured such as to rotate therewith and about which the hatch opens, a linear actuator having a ram capable of selective extension from or withdrawal 5 into an actuator body on actuation, said ram pivotally mounted to an offset cam which in turn is rotationally fixed to the shaft, and a swing arm pivotally mounted to- an external fixture at a first end and to the linear actuator at an opposed second end, the external fixture further including limitation means to limit rotation of the swing arm to a predetermined angle of rotation between a first and second 10 limit, wherein the mechanism is arranged such that, on actuation, the swing arm is either rotated to the first limit, thereby permitting the actuator to impart a torque to the shaft to open the hatch, or the swing arm is rotated to the second limit, thereby permitting the actuator to impart a torque to the shaft to close the hatch.

2. The opening mechanism according to claim 1, wherein the mechanism is 15 arranged such that actuation through sequential series of ram extensions and withdrawals the swing arm is rotated to the desired first or second limit and consequently applies a torque to the shaft.

3. The opening mechanism according to claim 1, wherein the angle of rotation of the swing arm is limited to less than 1800 degrees. 20

4. The opening mechanism according to claim 3, wherein the angle of rotation is 900 degrees.

5. The opening mechanism according to any one of the preceding claims, wherein the linear actuator is a pneumatic ram or hydraulic ram.

6. The opening mechanism according to any one of the preceding claims, 25 wherein the hatch covers an opening in a freight wagon or a semi-trailer.

7. The opening mechanism according to any one of the preceding claims, wherein the external fixture includes a pedestal. 9

8. The opening mechanism according to any one of the preceding claims, wherein the shaft is secured to a plurality of hatches in series such that on actuation the hatches open simultaneously.

9. The opening mechanism according to any one of the preceding claims, 5 wherein the shaft is connected to a pair of said linear actuators located at opposed ends of the shaft.

10. The opening mechanism according to any one of the preceding claims wherein actuation is initiated from a point remote from the opening mechanism.

11. The opening mechanism according to claim 9, wherein actuation is 10 initiated through a control device including a control panel or pendulum.

12. The opening mechanism according to claim 10, wherein the control device is in communication with the opening mechanism through a direct wire link.

13. The opening mechanism according to claim 10, wherein the control device is in remote communication with the opening mechanism through infrared or radio 15 link.

14. A method for opening a hatch mounted to a shaft including the steps of actuating an actuator, rotating a swing arm mounted to the actuator until the swing arm is in contact with a first limit, applying a torque by the actuator to an offset cam mounted to a ram of the actuator, rotating the shaft which is mounted 20 to an opposed end of the offset cam and opening the hatch.

15. A method for closing a hatch mounted to a shaft including the steps of actuating an actuator, rotating a swing arm mounted to the actuator until the swing arm is in contact with a second limit, applying a torque by the actuator to an offset cam mounted to a ram of the actuator, rotating the shaft which is mounted 25 to an opposed end of the offset cam and closing the hatch. 10

16. A freight wagon having a top opening which is selectively closable by means of at least one hatch, including a hatch opening mechanism according to any one of claims 1 to 13.

17. A hatch opening mechanism substantially as hereinbefore described with 5 reference to the accompanying figures. UNITED GROUP RAIL SERVICES LIMITED WATERMARK PATENT & TRADEMARK ATTORNEYS P20882AU00