GB2317867A

GB2317867A - A stop for a rail system

Info

Publication number: GB2317867A
Application number: GB9620698A
Authority: GB
Inventors: James Christopher Thorpe; Stephen George Miles
Original assignee: Polymark International Ltd
Current assignee: Polymark International Ltd
Priority date: 1996-10-04
Filing date: 1996-10-04
Publication date: 1998-04-08
Also published as: GB9620698D0

Abstract

A stop (31) for halting the movement of a trolley (21) along a rail (11) and which comprises a yoke (32) straddling the rail with a limb (33,34) located on each side of the rail (11), and a catch means (36) rotatably mounted on at least one limb and being rotatable from a first position engagable with the trolley to a second position in which it disengages from the trolley.

Description

A Stop for a Rail System Field This invention relates rail systems, especially overhead rail systems used for materials handling, and especially for use in commercial laundries.

Background In commercial laundries, dirty laundry and clean laundry are generally moved about the premises in collapsible bags which are supported at their upper ends by a rigid ring.

These rings in turn are generally moved about the laundry supported from overhead conveyor rails. The rails provide a track for the movement of trolleys from which the rings are suspended. The rail systems are generally inclined to the horizontal in order to use gravity to assist in the transfer of bags around the laundry.

It is sometimes necessary to halt the laundry bags at particular locations on the rail system.

Obiect of the Invention The present invention provides an improved stop for a rail system.

Statements of Invention Accordingly there is provided a stop for halting the movement of a trolley along a rail system and which comprises a yoke straddling the rail with a limb located on each side of the rail, and at least one catch means mounted on at least one limb for engagement with an abutment on a trolley, the catch means being movable between a first position in which it is engagable with the abutment and a second position in which it disengages from the trolley.

Preferably the catch means is rotatable from the first position to the second position, and may comprise a circular disc, or cylinder, rotatable about its centre and having a quadrant shaped notch therein, and in the first position the notch is open to one direction along the rail and in the second position the notch is open to the other direction along the rail.

Even in the release position for one trolley the catch means may act as an abutment for another trolley.

In use the catch means are located on the inside of a respective limb adjacent the rail and are rotationally fast with a lever or link located on the outside of the limb.

The lever or link may form part of a three bar linkage mechanism which converts the linear movement of an actuator to rotary movement of the catch means, and preferably said link has an elongated slot therein making a sliding connection with one end of a second link pivoted by a pin at its mid length to the yoke, the other end of the second link being movable to pivot the second link about the pin with consequential rotation of the link fixed to the catch means.

In the preferred mode a catch means is located on each limb of the yoke.

The invention also provides an overhead rail conveyor system for the transfer of material handling bags suspended from trolleys which move along the rail, wherein the system includes at least one stop according to the invention and which is arranged over the rail.

Description of Drawings The invention will be described by way of example and with reference to the accompanying drawings in which: Fig. 1 is a part front view and section of an overhead rail and trolley according to the invention, Fig. 2 is a side elevation of the stop in a 'halt' condition and showing the position of the catch means in detail, and Figs. 3 to 5 are side elevations as per Fig.2 showing the changes in the stop as it assumes the release position.

Detailed description of Example With reference to Fig. 1 of the drawings there is shown a section of overhead rail 11 having a central web 12 with a lower track portion 13 and an upper track portion 15 at each end of the web 12. The lower track portion 13 has an upper arcuate surface 14 extending on each side of the web 12 along which a trolley 21 can move. In use the rail 11 forms part of an overhead conveyor system for the movement of laundry bags around a commercial laundry.

The trolley 21 comprises a 'Y' shaped body 22 having two diverging arms 23, each arm 23 having a roller 26 mounted at its upper end portion on its inner side adjacent the rail 11. The trolley 21 is arranged so that a roller 26 is located on each side of the web 12 with the rollers moving along the arcuate surface 14. A steel shackle (not shown) is secured to the body 21 by a stainless steel pin 28 which extends transversely to the rail 11 and has end portions that project beyond the body. In use the end portions of the pin 28 act as abutments which in combination with a stop 31 prevent movement of the trolley 21 along the rail.

Now referring also to Fig.2, the stop 31 comprises a yoke 32 which is substantially 'U'shaped in transverse elevation and has a limb 33,34 located on each side of the rail 11. The yoke 32 is directed downwards with the bridge 35 between the limbs 33,34 resting on the upper track portion 15. The bridge 35 extends longitudinally of the rail to provide support for an actuator (not shown) but indicated schematically by arrow A. A catch means 36 is located at the lower end portion of each limb 33,34 on the inside of the respective limb adjacent the rail 11.

The two catch means 36 and their respective operating mechanisms are identical and so will only be described with reference to the limb 33. Each catch means 36 is a circular or cylindrical disc having a quadrant shaped notch 37 therein and is rotatably mounted on the respective limb 33 or 34. The catch means 36 may be mounted on a circular backing plate 39 having a central axle 38 passing through the limb 33. The axle 38 is rotationally fast with one end of a first link or lever 41 located on the outside of the limb. Rotational movement of the link 41 relative to the yoke 32 therefore causes the catch means 36 to rotate.

The link 41 has an elongated slot 42 therein extending towards the other end of the link 41 and is connected to one end of a second link 43 by a pivot pin 44 which is slidable along the slot 42. The second link 43 is pivoted to the yoke 32 by a pivot pin 45 located at a mid-length location and extends upwardly beyond the bridge 35 of the yoke 32. The two second links 45, located one on each limb 33,34, are interconnected by a cross-member 46 with a cross-pin 47 pivotally extending between the two links 43.

The yoke limb 33, and links 41, 43 form a three bar link mechanism.

An actuator A, for example a pneumatic actuator, or a solenoid operated actuator, has its actuation rod attached to the centre of the cross-pin 47. In Fig.2 the actuator rod is retracted and the catch means 36 is in a " catch condition" with the notch 37 located so that it faces in one direction along the rail which will be labelled the uprail direction, and its two sides 51, 52 face downwards and uprail respectively. In this position the notch 37 will act as an abutment for the pins 28 on any trolleys 21 moving down rail. A proximity indicator switch 53 is located at the lower end of one of the limbs 33 or 34 to sense the presence of a trolley and send a signal to a computer operated control means (not shown).

A trolley 21 held in the stop 31 is released by a signal from the control means to the actuator A causing the actuator rod to extend. This process is shown in Figs. 3 to 5.

The movement of the actuator rod is transmitted to the upper end portion of the second link 43 via the cross-pin 47 causing the second link 43 to pivot clockwise, as shown in Fig 3, around the pin 45. This in turn moves the pin 44 at the other end of the second link 43 down the slot 42 in the first link 41 which causes the first link 41 to rotate anti-clockwise as shown. Since the catch means 36 is rotationally fast with the first link 41 it is also rotated in a like manner.

As the actuator rod extends, the three bar link mechanism goes through a central position as shown in Fig. 4 and then goes over-centre as shown in Fig 5. to the final position where the trolley is released. In the final position the notch 37 faces along the rail in a down rail direction with the side 51 facing downrail and the side 52 facing downwards.

Thus as the actuator extends, the catch means 36 not only releases the trolley 21 but by acting on the pin 28 gives the trolley a push as the notch 37 moves from facing uprail to facing downrail.

Because the three bar mechanism goes over-centre the catch means 36 cannot be moved from the release position to the stop position, or vice versa, by applying a load to a trolley or a load suspended from a trolley.

The movement of the trolley 21 out of the stop 31 is sensed by the proximity switch 53 and a signal sent to the control means. Where laundry bags are suspended from a single trolley the bag will move off down rail, and where laundry bags are suspended from two trolleys 21 spaced along the rail 11 then to release the bag the stop will be operated twice.

The catch means 36 can still act as an abutment in the release position shown in Fig. 5. Any trolleys entering the stop 31 will abut the cylindrical surface of the catch means facing uprail and as the actuator A retracts moving the catch means, clockwise as shown, so that the notch 37 faces up rail the pin 28 will gradually feed into the notch.

Claims

1. A stop for halting the movement of a trolley along a rail system and which comprises a yoke straddling the rail with a limb located on each side of the rail, and at least one catch means mounted on at least one limb for engagement with an abutment on a trolley, the catch means being movable between a first position in which it is engagable with the abutment and a second position in which it disengages from the trolley.

2. A stop as claimed in Claim 1 wherein the catch means is rotatable from the first position to the second position.

3. A stop as claimed in Claim 2 wherein the catch means comprises a circular disc or cylinder rotatable about its centre and having a quadrant shaped notch therein, and in the first position the notch is open to one direction along the rail and in the second position the notch is open to the other direction along the rail.

4. A stop as claimed in Claim 2 or Claim 3, wherein each catch means is pivotally mounted to a respective limb

5. A stop as claimed in Claim 4, wherein each catch means is mounted on the inside of a respective limb adjacent the rail, and is rotationally fast with a first link located on the outside of said respective limb so that pivotal movement of the first link relative to the yoke causes the catch means to rotate.

6. A stop as claimed in Claim 6, wherein the first link has an elongated slot therein making a sliding connection with one end of a second link pivoted to the yoke by a pin at its mid length, the other end of the second link being movable to rotate the second link about the pin with consequential rotation of the first link.

7. A stop as claimed in Claim 6, wherein the second link projects beyond the yoke for connection with an actuator.

8. A stop as claimed in any one of Claims 1 to 7 wherein there is a catch means mounted on each limb of the yoke.

9. A stop as claimed in Claim 8 when dependant upon Claim 7, wherein the two projecting other end portions of the two second links are interconnected by a cross member and both catch means are simultaneously operable.

10. A stop as claimed in any one of Claims 1 to 9 wherein at least one limb of the yoke has a proximity switch secured thereon for sensing when a trolley is held at the stop, and which can send a signal to a control system for operation of an actuator to operate the catch means.

11. An overhead rail conveyor system for the transfer of material handling bags suspended from trolleys which move along the rail, wherein the system includes at least one stop as claimed in any one of Claims 1 to 10 and which is arranged over the rail.

12. A system as claimed in Claim 11 wherein each trolley includes a pin extending transversely of the rail, and the catch means engages the end portions of the pin.

13. A system as claimed in Claim 11 or Claim 12 wherein the stop, on moving from the first position to the second position also pushes the trolley along the rail.

14. A system as claimed in any one of Claims 11 to 13 further including a control system which operates an actuator to move the catch means from the first position to the second position.