GB2099772A

GB2099772A - Power-and-free conveyor systems

Info

Publication number: GB2099772A
Application number: GB8216679A
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: KR880002388B1; AR229420A1; AU8374082A; AU544069B2; JPS57209457A; IT1148322B; ES8305650A1; NZ200620A; IT1148323B; MX157650A; KR880002430B1; IT8248597A0; MX157651A; KR840000423A; JPS6411502B2; JPS6411503B2; GB2099771A; AR229054A1; ZA823308B; DE3221116A1

Abstract

The driving member (46) of each article carrier has 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 (92, 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 (92, 93) are engageable by forwarding and receiving pushers (42-1, 42-2) travelling on parallel side-by-side power tracks at a transfer zone where the driving member and pushers are relatively positioned vertically so that improper engagement between them is prevented by the anti-jam cam (82) and by beveled side surfaces (105, 104) on the driving wings and the pushers. 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

1 GB 2 099 772 A 1

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 75 direction and including pusher members projecting toward 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 members to be moved to non-operable relation with the pushers; 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 to be 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 95 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: 100 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; and 2. Transfer zones at which carriers can be accumulated and through which carriers can be propelled by forwarding and receiving pusher members without requiring a secondary driving member on each carrier and without interference 110 between the carrier driving member and the forwarding and receiving pusher members.

A conveyor system of the invention has a carrier track, carriers each including a driving trolley supported in the carrier track; at least one 115 driven pusher conveyor comprising a power track spaced vertically from the carrier track, carrier propelling means mounted on the power track and having 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, the driving member including a driving dog having a driving face normally engageable by a pusher in the operable position of the driving member; and a transfer zone to which a carrier is propelled by a forwarding pusher member and from which a carrier is propelled by a receiving pusher member; wherein the driving dog is provided with a pair of transversely extending wing portions each projecting to a respective side of the driving member and each having a continuation of the driving face; the transfer zone has an entrance end, an exit end and includes a forwarding power track defining the path of travel of a forwarding pusher member and a receiving power track defining the path of travel of a receiving pusher member; said forwarding and receiving power tracks between said entrance and exit ends have parallel portions offset to opposite sides of a vertical plane through the longitudinal centerline of the carrier track and extending parallel to said plane, said parallel power track portions positioning the forwarding and receiving pusher members in transversely spaced relation, a forwarding pusher member being engageable with one of the driving dog wing portions and a receiving pusher member being engageable with the other of the driving dog wing portions; each wing portion of the driving dog is provided with an anti-jam cam surface located forwardly of said driving face and adapted to move the driving dog to a non-operable position in response to overtaking engagement between said anti-jam cam surface and one of the forwarding and receiving pusher members; and, at the exit end of the transfer zone one of the forwarding and receiving power tracks diverges from the other.

Preferably, a conveyor system of the invention includes one or more of the following features; The driving trolley includes a holdback dog having a holdback face normally engageable by a pusher member, the wing portions of the driving dog project to each side of the holdback face, and the parallel power track portions are arranged so that th,- holdback face is nonengageable by at least one of the forwarding and receiving pusher members when positioned in transversely spaced relation; The parallel power track portions are arranged in substantially symmetrical relation to the vertical plane through the longitudinal centerline of the carrier track; At the entrance end of the transfer zone there is a convergence of one of the power tracks relative to the carrier track, and at least one of the elements consisting of the driving dog and the converging pusher member is provided with a beveled side surface engageable by the other of the elements at the convergence; The transfer zone includes positioning means which relatively locates the driving dog and at least one of the forwarding and receiving pusher members vertically and which limits overtaking engagement between the driving dog and the one pusher member to the engagement of the antijam cam surface. This positioning means also limits the lateral engagement between the driving dog and the one pusher member at the convergence to the engagement of the beveled side surface; The positioning means comprises a cam bar which is engageable by the driving dog, is 2 GB 2 099 772 A 2 mounted substantially symmetrically to the vertical plane through the longitudinal centerline of the carrier track, and extends substantially the length of the parallel power track portions. Alternatively, the positioning means comprises structure supporting at least one of the power tracks at an elevation relative to the carrier track such as to define the desired relative vertical location of the driving dog and pusher member; Each carrier is provided with accumulating means operable to move the driving member to non-operable position with respect to both the forwarding and the receiving pusher member at the transfer zone, and, the accumulating means includes an actuating cam integrally formed with the driving member and having an accumulating cam surface which is located forwardly of the driving dog and is engageable with an actuator on a preceding carrier; and, The wing portions of the driving dog and the parallel portions of the forwarding and receiving power tracks at the transfer zone are disposed within an operational space bounded by vertical planes through the transverse extremities of the carrier track.

The foregoing and other features of 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; 100 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 elevation of the trolley of Fig. 4; 105 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 110 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 115 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 Fig. 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 taken as indicated by the line 12-12 of Fig. 11; and Fig. 13 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 15 each projecting toward the Pther from one of the transversely spaced vertical web portions 16 extending perpendicular to the track surfaces. The upper flanges 18 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 a 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 3 1.

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 pusher 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 3 GB 2 099 772 A 3 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. Apertures 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 90 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 95 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 19 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 110 and 6 1, and in the diameter of the guide rollers 63 and 64 result in improved lateral stability which is particularly advantageous in conveyor systems of the type shown in Fig. 2 having a platform-like article carrying structure 30 115 located above the carrier track 10. The lateral stability of the structure 30 may be maintained solely by the engagement between the trolleys 22 and 24 and the carrier track supporting surfaces 15 and guide surfaces 19. These dimensional 120 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 50 125 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 interconnects130 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, 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 hold-back 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 anti-jam cam surface 82.

The accumulating cam surface 80 is located at the forward end of the actuating cam 76 and within the web portions 16 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 16 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 4 GB 2 099 772 A 4 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 transversely 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 9 1 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.

40' The driving dog 74 of the driving member 46 is 105 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 8 1, 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 2 1 -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 centerline 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 10 1 in the forwarding power track 12-1 to one side of the vertical plane 34, and a convergence 102 of the receiving power track 122 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 10.

Interference and jamming conditions between the driving member 46 of a carrier and the forwarding and receiving pusher members 42-1 and 42-2 are positively prevented by the following features 1. The wing portions 92 and 93 of the driving GB 2 099 772 A 5 dog 74 project to each side of the holdback face 79 of the holdback dog and the forwarding a6d receiving pushers 42-1 and 42-2 are nonengageable with the holdback face 79 when positioned in transversely spaced relation by the parallel forwarding and receiving track portions.

2. The side faces 103 of the pusher members 42-1 and 42-2 are each formed with a beveled surface 104 (Fig. 7), and a complementary beveled surface 105 is formed on the side face 106 of each wing portion 92 and 93 of the driving dog. Lateral interference, which could take place between the driving dog 74 and a receiving pusher 12-2 at the convergence 102 of the receiving track relative to the vertical plane 34, is prevented by the engagement of the beveled surfaces 104 and 105 which are adapted to move the driving member to non-operable position. Positioning means relatively locates the driving dog and receiving pusher member vertically so that any lateral engagement between them is limited to the beveled surfaces 104 and 105. This positioning means, in the transfer zone construction of Figs. 7 and 8, comprises a cam bar 107 which is supported symmetrically to the vertical plane 34 by the power tracks 12-1 and 12-2, extends from the entrance end 99 to the exit end 100 of the transfer zone, is engageable by the driving dog 74, and moves the driving member 46 from the full line to the broken line position shown in Fig. 8.

3. The cam bar 107 also limits any overtaking engagement between the driving dog and the forwarding and receiving pusher members 42-1 and 42-2 to the anti-jam cam surface 82.

As a result of the foregoing features the drive units 96-1 and 96-2 do not require any synchronization or interlock controls and can be operated at any desired speed differential. Should the driving member of a carrier, being propelled in the transfer zone 98- 1 by a pusher member on either the forwarding power track 12-1 or the receiving power track 12-2, engage a slower moving pusher member on the other power track, the driving member 46 will simply disengage and will be re-engaged by the next pusher member until the carrier clears the exit end 100. Should the driving member engage a stopped receiving pusher member, the same disengagement of the driving member 46 will occur but the carrier will not clear the transfer zone until the receiving pusher members are again moving. Any following carriers will accumulate behind the stopped carrier. If desired, the transfer zone can be made a part of the system where carriers are accumulated 120 by providing a stop member 91 at the exit side of, or even in the transfer zone 98-1.

Referring again to Fig. 1, from the transfer zone 98-1 a carrier proceeds through a processing station 108 and to a second transfer zone 98-2. 125 This zone is the same as the zone 98-1 except that a pusher member 42-2 acts as the forwarding pusher member and a pusher member 42-1 acts as the receiving one. The carrier is then advanced to a transfer zone 109-1 where a130 branch carrier track 10-1 connects with the main carrier track 10 through a switch 110. The power track 12-1 follows the branch carrier track 10-1 to a re-entry transfer zone 109-2, passes through a change in elevation at 111 and returns to the transfer zone 109-1 along the path 112 and elevation change 114. The transfer zones 109-1 and 109-2 illustrate an arrangement frequently employed in power and free conveyor systems where all the pusher members involved in a transfer are on the same chain, with one pusher member 42-1 acting as a forwarding pusher member and another pusher member 42-1 acting as a receiving pusher member.

Fig. 9 schematically illustrates an alternative positioning means to the cam bar 107 for relatively locating the driving dog and pusher members vertically at the transfer zone 109-1 where a pusher member 42-1 F is forwarding and a pusher member 42-1 R is receiving. Since these pusher members are on the same chain and are moving at the same speed, the only possible interference is the lateral interference that may occur at the convergence 115 of the receiving pusher at the entrance end of the transfer zone. Positioning is accomplished by arranging the structure supporting the power track of the receiving pusher 42-1 R at an elevation relative to the carrier track 10 such that lateral engagement between the driving dog wing portion 93 and a receiving pusher member 421 R is limited to the engagement of the beveled surfaces 104 and 105, at least in the region of the convergence 115. If such engagement should occur, the driving member 46 will be moved toward the non-operative position a distance sufficient to clear the receiving pusher 42-1 R but not sufficient for the driving dog wing portion 92 to disengage from the forwarding pusher member 42-1 F.

The arrangement of Fig. 9 can be used at the re-entry transfer zone 109-2 except that here the convergence is in, and the positioning means would be employed for, the power track 12-1, which does not support the receiving pusher members.

Both of the forwarding and receiving power tracks may be supported toposition their respective pusher members at the vertical elevation of the pusher member 42-1 R of Fig. 9 for the same results obtainable with the cam bar 107 of Figs. 7 and 8.

Another preferred feature shown in Figs. 7 and 9 is that the wing portions 92 and 93 are disposed within an operational area bounded by vertical planes through the transverse extremities of the carrier track members 13 and 14, and that the employment of parallel track members 32 and 33 for the power tracks enables the forwarding and receiving pusher members to be disposed within this area, thereby simplifying the track supporting structure.

Fig. 13 illustrates a carrier driving trolley 122 of the invention for an overhead power and free 6 GB 2 099 772 A 6 conveyor system having the power track mounted 65 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; at least one driven pusher conveyor comprising a power track spaced vertically from the carrier track, carrier propelling means mounted on the power track and having 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, the driving member including a driving dog having a driving face normally engageable by a pusher in the operable position of the driving member; and a transfer zone to which a carrier is propelled by a forwarding pusher member and from which a carrier is propelled by a receiving pusher member, wherein the driving Oog is provided with a pair of transversely extending wing portions each projecting to a respective side of the driving member and each having a continuation of the driving face; the transfer zone has an entrance end. An exit end and includes a forwarding power track defining the path of travel of a forwarding pusher member and a receiving power track defining the path of travel of a receiving pusher 100 member, said forwarding and receiving power tracks between said entrance and exit ends have parallel portions offset to opposite side of a vertical plane through the longitudinal centeffine of the carrier track and extending parallel to said 105 plane, said parallel power track portions positioning the forwarding and receiving pusher members in transversely spaced relation, a forwarding pusher member being engageable with one of the driving dog wing portions and a 110 receiving pusher member being engageable with the other of the driving dog wing portions; each wing portion of the driving dog is provided with an anti-jam cam surface located forwardly of said driving face and adapted to move the driving dog 115 to a non-operable position in response to overtaking engagement between said anti-jam cam surface and one of the forwarding and receiving pusher members; and, at the exit end of the transfer zone one of the forwarding and receiving power tracks diverges from the other.

2. A conveyor system according to claim 1, wherein the driving 'trolley includes a holdback dog having a holdback face normally engageable by a pusher member, said wing portions of the driving dog projecting to each side of the holdback face, and said parallel power track portions are arranged relative to said vertical plane so that the holdback face is non-engageable by at least one of the forwarding and receiving pusher members when positioned in said transversely spaced relation.

3. A conveyor system according to claim 1 or 2, wherein said parallel portions of the forwarding and receiving power tracks are arranged in substantially symmetrical relation to the vertical plane through the longitudinal centerline of the carrier track.

4. A conveyor system according to claim 1, 2 or 3, wherein there is at the entrance end of the transfer zone a convergence of one of the power tracks relative to the vertical plane through the longitudinal centerline of the carrier track; and, at least one of the elements consisting of the driving dog and the converging pusher member is provided with a beveled side surface engageable by the other of the elements at said convergence.

5. A conveyor system according to any of claims 1 to 4, wherein the transfer zone includes positioning means which relatively locates the driving dog and at least one of the forwarding and receiving pusher members vertically and which limits overtaking engagement between the driving dog and said one pusher member to the go engagement of said anti-jam cam surface.

6. A conveyor system according to claim 4, wherein the transfer zone includes positioning means which relatively locates the driving dog and at least one of the forwarding and receiving pusher members vertically and which limits the lateral engagement between the driving dog and said one pusher member at said convergence to the engagement of said beveled side surface.

7. A conveyor system according to claim 5 or 6, wherein said positioning means comprises a cam bar engageable by the driving dog, said cam bar being mounted substantially symmetrically to said vertical plane.

8. A conveyor system according to claim 7, wherein the cam bar extends substantially the length of said parallel power track portions.

9. A conveyor system according to claim 5 or 6, wherein said positioning means comprises structure supporting at least one of the power tracks at an elevation relative to the carrier track as to define said relative verticle location of the driving dog and pusher member.

10. A conveyor system according to any of claims 1 to 9, wherein each carrier is provided with accumulating means operable to move the driving member to non-operable position with respect to both the forwarding and the receiving pusher members at the transfer zone.

11. A conveyor system according to claim 10, wherein the accumulation means includes an actuating cam integrally formed with the driving member, the actuating cam having an accumulating cam surface located forwardly of the driving dog and engageable with an actuator on a preceding carrier.

12. A conveyor system according to any of claims 1 to 11, wherein the wing portions of the driving dog and the parallel portions of the forwarding and receiving power tracks at the 1 7 GB 2 099 772 A 7 transfer zone are disposed within an operational space bounded by vertical planes through the transverse extremities of the carrier tracks.

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

Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1982. Published by the Patent Office, 25 Southampton Buildings, London, WC2A 1 AY, from which copies may be obtained.