GB2099771A

GB2099771A - Power-and-free conveyor systems

Info

Publication number: GB2099771A
Application number: GB8216678A
Authority: GB
Original assignee: Jervis B Webb International Co
Current assignee: Jervis B Webb International Co
Priority date: 1981-06-10
Filing date: 1982-06-09
Publication date: 1982-12-15
Also published as: KR840000423A; AU544069B2; JPS6411503B2; ZA823308B; NZ200621A; YU124782A; DE3221116C2; MX157650A; GB2099772A; KR880002430B1; KR840000424A; FR2507582A1; CA1190503A; DE3221116A1; ES8305650A1; ZA823309B; BR8203370A; JPS57209458A; JPS57209457A; BE893438A

Abstract

A driving trolley (22) has a movable driving member (46) engageable with a driven pusher (42). Formed integrally with the driving member (46) are: a stopping cam (81) and an abutment (90), an accumulation cam (80), an anti-jam cam (82), and a pair of transversely projecting driving wings (93, 93), all cams being adapted to disengage the driving member from a pusher. The stopping cam (81) and abutment (90) are engageable with a trackside stop member to stop the carrier; the accumulating cam (80) is engageable with an actuator on the rear of a preceding carrier, also to stop the carrier; and the driving wings are engageable by forwarding and receiving pushers travelling on parallel side-by-side power tracks at a transfer zone. Carrier bumpers (87, 88) and actuators are located within and protected by the web portions of channel-section carrier track members which can be mounted either above or below the power track. <IMAGE>

Description

SPECIFICATION Conveyor systems This invention relates to conveyor systems.

Conveyor systems of the power and free type conventionally include a carrier track, carriers each having a driving trolley supported on the carrier track, a power track spaced vertically from the carrier track, and carrier propelling means mounted on the power track, the propelling means being normally driven in a forward direction and including pusher members projecting towards the carrier track. The driving trolley has a driving member which is movable between operable and non-operable positions with respect to a pusher member and which is biased to the operable position.

Other conventional features of such conveyor systems include: 1. The capability of stopping and accumulating carriers by causing their driving member to be moved to non-operable relation with the pusher; and 2. In more complex systems, the capability of providing transfer zones to which a carrier is propelled by a forwarding pusher and from which the carrier is propelled by a receiving pusher, the forwarding and receiving pushers usually (but not necessarily) being part of separately driven forwarding and receiving propelling means so that carrier speed, or relative spacing, or both, may be varied as desired throughout the system.

The conveyor system of the present invention can be designed to offer several additional constructional and operational features including: 1. The capability of providing two types of conveyor systems, one having the power track located below the carrier track and the other having the power track located above the carrier track; 2. Stops which positively arrest forward movement of a carrier; and 3. Carrier bumpers and accumulating mechanism which are located within a protected space partially enclosed by the structural members forming the carrier track.

A conveyor system of the invention, has a carrier track, carriers each including a driving trolley supported on the carrier track, a power track, carrier propelling means mounted on the power track and normally driven in a forward direction, the carrier propelling means including pusher members projecting toward the carrier track, the driving trolley having a driving member movable between operable and nonoperable positions with respect to a pusher member and biased to the operable position; wherein the driving member includes an end portion which extends from the driving trolley toward the power track and which is integrally formed with a driving dog and an actuating cam, the driving dog having a driving face engageable by a pusher in the operable position of the driving member, and the actuating cam extending from the driving member in the forward direction; a first accumulating cam surface is provided on the actuating cam, and each carrier is provided with a rearwardly extending actuator adapted to be engaged by the accumulating cam surface of a following carrier for moving the driving member of such following carrier to the non-operable position, a second stopping cam surface is provided on the actuating cam, said stopping cam surface being located between the first accumulating cam surface and the driving face of the driving dog and extending to an abutment surface formed on the driving member forwardly of the driving face of the driving dog; and a stop member, positionable in the path of movement of the end portion of the driving member, is engageable by the second stopping cam surface to move the driving member to non-operable position, and is engageable by the abutment surface to stop the carrier.

Preferably, a holdback dog is integrally formed with the driving member and has a holdback face engageable by a pusher member in the operable position of the driving member, the holdback dog being nonengageable by a pusher member in the non-operable position of the driving member.

Preferably also, a conveyor system of the invention includes one or more of the following features: The actuating cam has a third anti-jam cam surface which is located outwardly of the abutment and extends toward the driving face and which is adapted to move the driving member toward non-operable position in response to engagement between the anti-jam cam surface and a pusher member overtaken thereby; The driving dog has a pair of wing portions each projecting transversely to one side of the actuating cam and provided with the driving face of the driving dog, the transverse extent of the wing portions being such that the driving face is engageable by a pusher member of each of a pair of carrier propelling means mounted on a pair of power tracks arranged in side-by-side relation; and, the third anti-jam cam surface is formed on the pair of wing portions; The stop member is engageable by a wing portion of the driving dog to limit movement of the driving member to non-operable position in response to engagement of the stop member by the second stopping cam surface; The wing portions of the driving dog project to each side of the holdback face of the holdback dog and the driving face of each wing portion is engageable by a pusher member in nonengageable relation with the holdback face of the holdback dog; The abutment surface on the driving member projects transversely to each side of the holdback face of the holdback dog;; The accumulating cam surface of the actuating cam and the actuator are located within transversely spaced vertical web portions of the carrier track, and each carrier is provided with forwardly and rearwardly projecting bumpers also located within these transversely spaced vertical web portions of the carrier track; and, The driving member is biased by its weight to the operable position, or alternatively is connected to a lever pivoted on the driving trolley and having a counterweight portion adapted to bias the driving member to the operable position.

The invention will be further described by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a schematic plan view of a representative conveyor system illustrating features of the invention; Fig. 2 is a side elevation of a load carrier of a type of conveyor system of the invention in which the power track is located below the carrier track; Fig. 3 is an end elevation of Fig. 2 showing the track structure; Fig. 4 is an enlarged side elevation of the driving trolley of the load carrier of Fig. 2; Fig. 5 is an end elevation of the trolley of Fig. 4; Fig. 6 is a side elevation showing an accumulated relation between a trailing trolley of one carrier and a driving trolley of a following carrier;; Fig. 7 is a fragmentary sectional elevation taken as indicated by the line 7-7 of Fig. 1 showing the relation between the driving trolley and forwarding and receiving pushers at one type of transfer; Fig. 8 is a fragmentary side elevation further illustrating various relationships between the driving trolley and pushers in the transfer of Fig. 7; Fig. 9 is a fragmentary sectional elevation taken as indicated by the line 9-9 of Figs. 1 showing the relation between the driving trolley and forwarding and receiving pushers at another type of transfer; Fig. 10 is a fragmentary side elevation taken as indicated by the arrow 10 of Fig. 1 showing the relation between the driving trolley and a stop member; Fig. 11 is a sectional elevation taken as indicated by the line 11-11 of Fig. 10;; Fig. 12 is a plan view as indicated by the line 12--12 of Fig. 11;and Fig. 1 3 is a side elevation of an alternative driving trolley of the invention modified for use in a conveyor system of the invention in which the carrier track is located below the power track.

Figs. 2 and 3 illustrate a conveyor system of the invention in which a carrier track 10 is located above a power track 12. The carrier track 10 is formed by a pair of channel-section track members 13 and 14 (Fig. 3), the lower flanges of which provide a pair of carrier supporting track surfaces 1 5 each projecting toward the other from one of the transversly spaced vertical web portions 16 extending perpendicular to the track surfaces. The upper flanges 1 8 of the track members 13 and 14 provide a pair of opposed guide surfaces 19.

A carrier 20 is supported on the carrier track 10 and will of course have a configuration suited for the article or articles being handled in a particular conveyor system. The representative form of carrier shown in Fig. 2 consists of a leading driving trolley 22, an intermediate load carrying trolley 24 and a trailing load carrying trolley 26. A tow bar 27 is connected to the driving trolley 22 and to the intermediate trolley 24 with universal type connections 28. Load carrying structure 30 is connected to each of the intermediate and trailing trolleys 24 and 26 by a vertical pivot pin 31.

Other possible carrier configurations include a carrier having a driving trolley 22 and a trailing trolley 26 with load supporting structure connected to either or both of these trolleys; or, a carrier having only a driving trolley 22 with load carrying structure connected thereto. Any carrier will include a driving trolley 22, regardless of what other carrier components may be employed.

The power track 12 is spaced vertically from the carrier track 10 and as shown in Fig. 3, consists of a pair of channel-section track members 32 and 33 mounted in a transversely spaced toe-to-toe relation which is normally symmetrical to a vertical plane 34 extending through the longitudinal centerline of the carrier track 10. Structural frames 36 support the carrier and power tracks 10 and 12 at longitudinally spaced intervals as shown in Fig. 2. Each frame 36 consists of a pair of vertical channel-section supports 37 for the carrier track members 13 and 14, a transverse angle section member 38 joined to the supports 37 and to the power track members 32 and 33, and a base member 39 which is secured to each of the other components of the frame 36 and may be mounted on any suitable foundation at any elevation desired.

Carrier propelling means 40 (Fig. 2) are mounted on the power track 12, are normally driven in a forward direction as indicated by the arrow 41, and include pushers members 42 projecting toward the carrier track 10. In the particular construction shown, the pusher members 42 are formed on links 43 of an endless chain 44 connected to power trolleys 45 which travel on the power track 12. Other forms of propelling means conventionally employed in power and free conveyor systems can also be used.

Referring to Figs. 2, 4 and 5, the driving trolley 22 has a driving member 46 movable between operable and non-operable positions with respect to a pusher member 42, and biased to the operable position shown in Fig. 2 and in solid line in Fig. 4. The driving member 46 includes an end portion 48, which extends from the driving trolley 22 toward the power track 12, and a stem portion 50 which is movably mounted within the driving trolley body 52 by suitable means to be described.

The trolley body 52 comprises a pair of transversely spaced, interconnected side plates 54 having wheel supporting portions 55 disposed within the carrier track 10 and carrying portions 56 disposed externally of the carrier track. Aper tures 57 are provided in the portions 56 for connecting the tow bar 27 or load carrying structure to the trolley body. Front and rear axles 58 and 59 extend between the portions 55 with a pair of front and a pair of rear load carrying wheels 60 and 61 being mounted on the axles 58 and 59, respectively. Spacers 62 (Fig. 5) position the wheels 60 and 61 outwardly of the side plates 54. The tread dimension between each pair of wheels is considerably greater than normal practice for free trolleys of power and free conveyor systems, and requires a corresponding increase in the transverse spacing between the carrier track members 13 and 14.Front and rear guide rollers 63 and 64 are each mounted on a stub axle 65 secured to a block 66 interconnected between the carrying portions 56 of the side plates 54. Each of the guide rollers 63 and 64 is engageable with the guide surfaces 1 9 of the carrier track members and has a diameter corresponding to the increased spacing between these guide surfaces and corresponding substantially to the diameter of the wheels 60 and 61.

The dimensional increases in the transverse spacing between the carrier track members 13 and 14, in the tread of the load carrying wheels 60 and 61, and in the diameter of the guide rollers 63 and 64 result in improved laterai stability which is particularly advantageous in conveyor systems of the type shown in Fig. 2 having the platform-like article carrying structure 30 located above the carrier track 10. The lateral stabiiity of the structure 30 may be maintained solely by the engagement between the trolleys 22 and 24 and the carrier track supporting surfaces 1 5 and guide surfaces 19. These dimensional increases, in the case of the driving trolley 22, also contribute to several other advantages resulting primarily from the construction of the driving member 46.

As shown in Figs. 4 and 5, the stem portion 50 of the driving member 46 is movably mounted between the trolley body side plates 54 and between longitudinally spaced guides consisting of a roller bushing 67 on the front axle 58 and a guide portion 68 of a web 69 which interconnects the side plates 54. the inner end 70 of the stem portion is connected to an arm 71 carried by a pivot pin 72 mounted between the side plates.

The driving member 46 of the trolley of Figs. 4 and 5 is biased to the operable position by its weight, and the arm 71 serves primarily to define this position by engaging an abutment 73 on the trolley body.

The end portion 48 of the driving member 46 is integrally formed with a driving dog 74 and an actuating cam 76, the driving dog 74 having a driving face 75 engageable by a pusher 42 in the operable position of the driving member and the actuating cam 76 extending from the driving dog in the forward direction 41. A holdback dog 78 is also integrally formed with the driving member 46 in the construction shown and has a holdback face 79 engageable by a pusher 42 in the operable position of the driving member; however, the holdback face projects outwardly less than the driving face 75 and is of limited width, as shown in Fig. 5. Provided on the actuating cam 76 are a first accumulating cam surface 80, a second stopping cam surface 81, and a third antijam cam surface 82.

The accumulating cam surface 80 is located at the forward end of the actuating cam 76 and within the web portions 1 6 of the carrier track members 13 and 14. As shown in Figs. 2 and 6, each carrier is provided with a rearwardly extending actuator 84 adapted to be engaged by the accumulating cam surface 80 of a following carrier for moving the driving member 46 of the following carrier to the non-operable position shown in full line in Fig. 6.

Complementary retaining surfaces 85 of the accumulating cam 80 and 86 of the actuator 84 maintain the driving member 46 in this position.

Each carrier is also provided with a forwardly projecting bumper 87 and a rearwardly projecting bumper 88 located within the web portions 1 6 of the carrier track members 13 and 14. As illustrated in Fig. 6, the rearwardly projecting bumper 88 of one carrier is engageable by the forwardly projecting bumper 87 of a following carrier when the driving member 46 of the following carrier has been moved to the nonoperable position in response to the engagement of the actuator 84 of the one carrier by the accumulating cam surface 76 of the following carrier. The retaining surfaces 85 and 86 are so arranged that the driving member is in nonoperable position prior to engagement of the bumpers 87 and 88.

Figs. 2 and 6 illustrate the manner in which the actuator 84 and the bumpers 87 and 88 are installed on the multiple-trolley carrier 20. The forward bumper 87 is mounted on the body 52 of the driving trolley 22; while the actuator 84 and rearward bumper 88 are mounted on the body of the trailing trolley 26 (and optionally also on the body of the intermediate trolley 24, as shown in Fig. 2, if a maximum density accumulation zone is desired). In a conveyor system having carriers each including only a single driving trolley, an actuator 84 and a rearward bumper 88 would be mounted on the body of each such driving trolley.

The second stopping cam surface 81 of the actuating cam 76 is located between the first accumulating cam surface 80 and the driving face 75 of the driving dog and extends to an abutment surface 90 formed on the driving member 46 forwardly of the driving dog. In the operable position of the driving member shown in Fig. 4, the stopping cam surface 81 is located externally of the carrier track 10 and functions in the manner shown in Figs. 10-12. A stop member 91 (movable transversly of the carrier track 10 in the known manner) is positionable in the path of movement of the end portion 48 of the driving member 46, is engageable by the stopping cam surface 81 to move the driving member to nonoperable position as shown in Fig. 11, and is engageable by the abutment surface 90 as shown in Figs. 10 and 12 to stop the carrier.When the holdback dog 78 is integrally formed with the driving member 46, that dog also becomes nonengageable by a pusher member 42 when the driving member 46 is moved to non-operable position by the stop member 91. The abutment surface 90 projects to each side of the holdback face 79 to prevent interference of the holdback face with the stop member 91 when it is disengaged.

The third anti-jam cam surface 82 of the actuating cam 76 is located outwardly of the abutment surface 90 and extends toward the driving face 75 of the driving dog. This anti-jam cam surface 82 is adapted to move the driving member 46 toward non-operable position in response to engagement between the anti-jam cam surface 82 and a pusher member 42 overtaken thereby, which engagement may occur, for example, at a transfer zone.

The driving dog 74 of the driving member 46 is preferably provided with a pair of integral transversely extending wing portions 92 and 93.

Each of these wing portions project to one side of the driving member and project from the actuating cam rearwardly and outwardly of the abutment surface 90. Each wing portion 92 and 93 is provided with a continuation of the driving face 75 and with a continuation of the anti-jam cam surface 82. Each wing portion 92 and 93 also projects to one side of the holdback dog 78.

These wing portions coact with stop members 91 and with pushers 42 at a transfer zone.

Referring again to Figs. 10-12, the stop member 91 is formed with an offset portion 94 which extends forwardly and to one side of the stopping surface 95 of the stop member. The forward extent of the offset portion 94 is such that as the driving member 46 is moved to nonoperable position in response to engagement of the stop member 91 by the stopping cam surface 81, the offset portion 94 is overlapped and is engageable by one of the wing portions 93 of the driving dog 74. Movement of the driving member 46 is thereby limited and engagement of the stopping surface 95 of the stop member 91 by the abutment surface 90 of the driving member 46 is assured.

The coaction between the wing portions 92 and 93 of the driving member 46 and pushers 42 will be described in connection with the conveyor system schematically shown in Fig. 1. In this system, which is not intended to represent any particular system but to merely illustrate the manner in which the present invention is used, the path of the carrier track 10 appears as a solid line. A carrier travelling around the system in a clockwise direction and located on the vertical line at the left hand side of Fig. 1, is propelled by a pusher member 42-1 of a chain driven by a drive unit 96-1 and travelling in a path defined by a power track 12-1 represented in broken line.

The relation between the carrier track 10 and the power track 12-1 along this portion of the system is the normal one shown in Figs. 2-5, the pusher and driving members being symmetrical to the vertical plane 34 through the longitudinal centreline of the carrier track 10 and the pusher member being engageable with the driving and holdback faces 75 and 79 of the driving and holdback dogs 74 and 78 of the driving member 46.

As the carrier proceeds to the right on the upper horizontal track line of Fig. 1, it enters a transfer zone 98-1 to which it is propelled by a pusher member 42-1 (acting as a forwarding pusher member) and from which it is to be propelled by a pusher member 42-2 (acting as a receiving pusher) of another chain independently driven by a drive unit 96-2 and travelling in a path defined by a power track 12-2. The transfer zone 98-1 has an entrance end 99, and an exit end 100. At the entrance end 99 there is an offset 101 and the forwarding power track 12-1 to one side of the vertical plane 34, and a convergence 102 of the receiving power track 12-2 relative to the vertical plane 34.Between the entrance end 99 and the exit end 100, the forwarding and receiving power tracks 12-1 and 12-2 have parallel portions which, as shown in Fig. 7, are offset to opposite sides of the vertical plane 34, extend parallel thereto, and preferably are arranged in substantially symmetrical relation therewith. These parallel power track portions position the forwarding and receiving pusher members 42-1 and 42-2 in a transversely spaced relation at which a forwarding pusher member 42-1 is engageable with one of the driving dog wing portions 93 and a receiving pusher member is engageable with the other of the driving dog wing portions 92. At the exit end 100, the forwarding power track 12-1 diverges from the receiving power track 12-2 which converges into the normal vertically aligned relation with the carrier track 1 0.

Fig. 1 3 illustrates a carrier driving trolley 122 of the invention for an overhead power and free conveyor system having the power track mounted above the carrier track 10. The trolley 122 is essentially the same as the driving trolley 22 except that a lever 116 is employed in place of the arm 71 and is provided with a counterweight portion 118 adapted to bias the driving member 46 to the operative position shown relative to a pusher member 42.

Claims

1. A conveyor system having a carrier track, carriers each including a driving trolley supported on the carrier track, a power track, carrier propelling means mounted on the power track and normally driven in a forward direction, the carrier propelling means including pusher members projecting toward the carrier track, the driving trolley having a driving member movable between operable and non-operable positions with respect to a pusher member and biased to the operable position, wherein the driving member includes an end portion which extends from the driving trolley toward the power track and which is integrally formed with a driving dog and an actuating cam, the driving dog having a driving face engageable by a pusher in the operable position of the driving member, and the actuating cam extending from the driving member in the forward direction; a first accumulating cam surface is provided on the actuating cam, and each carrier is provided with a rearwardly extending actuator adapted to be engaged by the accumulating cam surface of a following carrier for moving the driving member of such following carrier to the non-operable position; a second stopping cam surface is provided on the actuating cam, said stopping cam surface being located between the first accumulating cam surface and the driving face of the driving dog and extending to an abutment surface formed on the driving member forwardly of the driving face of the driving dog; and a stop member, positionable in the path of movement of the end portion of the driving member, is engageable by the second stopping cam surface to move the driving member to non-operable position, and is engageable by the abutment surface to stop the carrier.

2. A conveyor system according to claim 1 wherein a holdback dog is integrally formed with the driving member and has a holdback face engageable by a pusher in the operable position of the driving member, the holdback dog being non-engageable by a pusher in the non-operable position of the driving member.

3. A conveyor system according to claims 1 or 2 wherein the actuating cam is provided with a third anti-iam cam surface located outwardly of the abutment surface and extending toward the driving face, said anti-jam cam surface being adapted to move the driving member toward nonoperable position in response to engagement between said anti-jam cam surface and a pusher member overtaken thereby.

4. A conveyor system according to claim 1, 2 or 3, wherein the driving cog of the driving member includes a pair of wing portions each projecting transversely to respective side of the actuating cam, and the driving face of the driving dog is provided on each of said pair of wing portions, the transverse extent of the wing portions being such that the driving face of the driving dog is engageable by a pusher member of each of a pair of carrier propelling means mounted on a pair of power tracks arranged in side-by-side relation.

5. A conveyor system according to claim 3 and 4, wherein said anti-jam cam surface is also formed on the wing portions of the driving dog.

6. A conveyor system according to claim 1,2 or 3, wherein the driving dog of the driving member includes a wing portion which projects transversely from the actuating cam rearwardly and outwardly of the abutment surface, and the stop member is engageable by said wing portion of the driving dog to limit movement of the driving member to non-operable position in response to engagement of the stop member by the second stopping cam surface.

7. A conveyor system according to claim 1, wherein the carrier is provided with a holdback dog having a holdback face engageable by a pusher, and the driving member includes a pair of transverse wing portions projecting to each side of the holdback dog and each provided with a driving face engageable by a pusher member in non-engageable relation with the holdback face of the holdback dog.

8. A conveyor system according to claim 1, wherein the carrier is provided with a holdback dog having a holdback face engageable by a pusher, and the abutment surface of the driving member projects transversely to each side of the holdback face.

9. A conveyor system according to claim 7 or 8, wherein the holdback dog is integrally formed with a driving member.

10 A conveyor system according to any of claims 1 to 9, wherein the accumulating cam surface of the actuating cam and the actuator are located within transversely spaced vertical web portions of the carrier track.

11. A conveyor system according to any of claims 1 to 10, wherein each carrier is provided with forwardly and rearwardly projecting bumpers located within transversely spaced vertical web portions of the carrier track the rearwardly projecting bumper of one carrier being engageable by the forwardly projecting bumper of a following carrier.

12. A conveyor system according to any of claims 1 to 11, wherein the driving member is biased by its own weight to the operable position.

13. A conveyor system according to any of claims 1 to 11, wherein the driving member is connected to a lever pivoted on the driving trolley and having a counterweight portion adapted to bias the driving member to the operable position.

14. A conveyor system constructed and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.