The present invention relates to switch mechanisms for conveyors, and in particular gear switches and trolley stops for use with conveyor assemblies.
It is known to use overhead rail systems along which trolleys travel in order to move goods during processing or manufacture. The systems are used for transporting various types of merchandise, including hanging meat, garments and other products, through manufacturing, warehousing and distribution facilities. One typical overhead conveyer system pushes heavy, metal trolleys along a track system. The trolleys carry loads of products. The overhead rail systems are designed and installed so that goods may be suspended from the trolleys and then moved in different directions along the rail system to transfer the goods from a first location to a second location. Some such systems employ a system of two, parallel tracks or rails; an upper power rail and a lower free rail. The upper rail generally includes a drive chain that engages a component of the trolley, while the trolley's wheels are designed to ride within the free rail. The load supported by the trolley is most often suspended below the level of the free rail.
Oftentimes, overhead rail systems use a rail switching mechanism at points in the track or rail where rails traveling in different directions intersect. The switching mechanism operates to control and direct the movement of the trolleys along various routes of the track system, such as to introduce a turn onto a different rail.
One form of switching mechanism is a gear switch. Current gear switches are typically formed of an assembly including two gear assemblies, each of which are operable to move gates into and out of engagement with a rail section connected thereto. The two gear assemblies in current switching mechanisms are arranged such that they are horizontally spaced apart in a plane which is perpendicular to the rail and at a height which is approximately parallel to each other and the rail. More specifically, the pivot axis of each of the gear assemblies is level and positioned in the same plane.
In a common conveyor assembly using a gear switch mechanism, a power chain is run through a bridge which is often used to connect first and second rail sections forming a portion of the rail switch assembly. In conveyors, projections, often referred to as pusher dogs, are suspended from the drive chain. A pusher dog assembly may be provided for the transportation of products on trolley in a conveyer system. A pusher dog is, generally, a projection that engages and pushes loads along a track or conveyor system. Thus, a power chain or drive chain pusher dog may be engaged to the chain and may be designed to directly engage trolley and push them along the series of interconnected rails. Movement of the trolley is thus accomplished by the mechanized action of the pusher dog on a protruding trolley part. Therefore, the drive chain commonly includes a pusher dog that extends downward from the drive chain and engages a part of the trolley that protrudes above the level of the free track or rail.
Unfortunately, current switching mechanisms, due to the travel path and location of the gear assemblies carrying the gate members, are prone to catch or bind with the pusher dog if the gate is switched at the wrong time. Thus, a high level of precision and timing must be used to switch the rail, or the drive chain must be stopped.
Additionally, in current switching mechanisms, a trolley stop is used to prevent overrun or interference of a trolley with a rail that is not currently being used. A current trolley stop used with such switch mechanisms is formed by a piece or member that is connected on the side of the rail section by a pivot member. At the lower end of the trolley stop is a weight, which causes rotation about the pivot member. Unfortunately, due to the side attachment of the trolley stop to the rail, and the position of the weight, these trolley stops are prone to bind. Moreover, the gate member must be precisely closed, coming over the top of the mechanism, or the gate may become wedged in place in the gate receptor, inhibiting the switching of the rails.
Accordingly, what is needed in the art is a rail switching mechanism that can be switched without binding. There is also a need in the art for a trolley stop for such a switch mechanism that may pivot on center or near center with the rail to stop the trolley or engage the switching mechanism.
A switch for a conveyor assembly is provided. The switch has a rail section forming a portion of the conveyor assembly. The switch also includes a first gear assembly pivotable about a first pivot axis and carrying a first gate, as well as a second gear assembly pivotable about a second pivot axis and carrying a second gate. The second pivot member is positioned below a plane extending perpendicular to the rail section from the first pivot axis.
A trolley stop for a conveyor assembly is also provided. The trolley stop comprises a body having a first side portion and a second side portion arranged to be disposed on first and second sides of a rail section. A pivot member extends through the body and at least a portion of the rail section. A stop member may be carried by an upper portion of the body. A weight may also be carried by the body, and is arranged to position the stop member for engagement with a trolley.
A conveyor assembly is further provided. The conveyor assembly includes a switch assembly for use in directing items along various paths in a rail system, wherein said switch assembly has a first rail section, a first gear assembly pivotable about a first pivot axis and carrying a first gate, as well as a second gear assembly pivotable about a second pivot axis and carrying a second gate. The second pivot member is positioned below a plane extending perpendicular to the rail section from the first pivot axis. The conveyor assembly also includes a trolley stop positioned on a second rail section having a body with a first side portion and a second side portion arranged to be disposed on first and second sides of the second rail section, a pivot member extending through the body and at least a portion of the second rail section, a stop member carried by an upper portion of the body, and a weight carried by the body arranged to position the stop member for engagement with a trolley when the first gate is engaged with the first rail section.
In an exemplary embodiment of a conveyor assembly having the foregoing components the second pivot axis provides a lower travel path and approximate side-action of the gate which reduces if not eliminates interference with the trolley, pusher dogs and/or drive chain. Furthermore, unlike traditional trolley stops which are often positioned to the side of the rail, the centralized positioning of the rail section in relation to the weighted pivotal movement of the trolley stop assembly permits the trolley stop assembly to rotate smoothly without binding. Other advantages and features may become apparent from the following description, drawings, and claims.
The invention will now be described, by way of example, with reference to the attached drawings, of which:
While the disclosure herein is particularly described with regard to overhead trolley conveyors, it will be understood and apparent to those of skill in the art that the present invention has other applications where switching mechanisms are used at points where rails or tracks intersect, in order to direct the objects moving along a track system.
Generally, rail switching mechanisms include a switch mounting which may be suspended from a ceiling or attached to a wall, beam, or other support, and which is used to support the rail sections used in the switching mechanism. The rail sections which are used may be either straight rail sections or curved rail sections. The rail sections may be bolted to the switch mounting, or they may be connected by welding them to the switch mounting. The rail sections used in the switching mechanism also contain one or more gate receptors for receiving the gates which are attached to the rail section. The gate receptors are formed by the absence of a portion of the rail so that a gate can close and be seated in the gate receptor. The opening and closing of the gates controls the movement of trolleys along intersecting rails in the rail system. An exemplary rail switching mechanism is shown in U.S. patent application Ser. No. 11/836,268 filed Aug. 9, 2007, which is hereby incorporated by reference in its entirety herein.
The Figures illustrate a switch assembly 10 for a conveyor as described herein. In an exemplary embodiment, the switch assembly 10 is a gear switch assembly in that the mechanism by which tracks or rails are changed is facilitated, at least in part, by a gear or combination of gears or gear assemblies. In
The foregoing assembly 10 may be attached to a larger conveyor assembly including a plurality of rail sections, such as two or more rail sections. Additionally, the switch assembly 10 may be used in association with a drive chain 22 or track having one or more pusher dogs 24 thereon. The rail 12 or 16 may also carry a trolley 26 adapted to carry or transport product (see
The gear switch assembly 10 generally includes a rail section 12 and/or 16, as well as a first gear assembly 28 and a second gear assembly 30 carried by a mounting member 32 carried by the rail section 12. The switch assembly 10 may thus include at least one rail section 12 or a portion of a rail section (see
The rail section 12 also has a first side portion 44 and a second side portion 46. The first side portion 44 carries a mounting member 32 or portion which has first and second gear assemblies 28, 30 (see
The first and second plates 48, 50 carry the first pivotable gear assembly 28. The first gear assembly 28 as shown in
The second pivotal gear assembly 30 may be carried by the first and second transfer plates 48, 50. The second gear assembly 30 includes second pivot member 66 or pin which is rotatably or pivotably received by the second apertures 64 in the first and second plates 48, 50 (see
In an exemplary embodiment, as best seen in
The foregoing assembly may be formed of any suitable materials for use with conveyor assemblies. In an exemplary embodiment, any one or more of the components of the conveyor assembly, switch assembly or rails described herein may be formed of metal, such as stainless or galvanized steel, aluminum, and the like, as well as plastics, composites, and combinations of any of the foregoing. The components may be integrally formed, or formed separately and connected together, such as by welding, adhesive, tongue and groove, fasteners, and the like. Also, the rail sections, gates, and other components of the assemblies described herein may be formed by any suitable means, and may include CNC cutting, drilling, or otherwise removing of a portion from a solid piece of material. This may include, but is not limited to, use of a laser, a plasma cutting device, or a water jet. Alternative methods of forming the rail and components of the gate are contemplated, including, but not limited to die cut and mold.
The switch assembly 10 may be formed by connecting the first and second transfer plates 48, 50 to the first rail 12, assembling the first and second gear assemblies 28, 30 on the transfer plates 48, 50, such as by inserting the pivot members 62, 66 through the apertures 60, 64 in the transfer plates and into the housings 76, 92 and/or gears 84, 88 of the gear assemblies. The gear assemblies 28, 30 may be formed by attaching the gate member 40 or 42 to the arm or lever 80, 96 and attaching the arm or lever to the housing 76, 92. The first rail section 12 may be attached to the second rail section 16 by, for example, connecting the bridge 18 with the first rail section 12 and the second rail section 16. While a specific arrangement and order of assembly is described, the forgoing is provided by way of example only, and any suitable arrangement or order may be acceptable for purposes of the present invention.
Generally, the rail sections 12 and 16 of the switch assembly 10 may be formed into a larger conveyor assembly by attachment of one or more additional rail sections to the ends of first and second rail sections.
In operation of the exemplary embodiment of the switch assembly 10 shown in
More specifically, the second gear 88 pivots or rotates in a direction opposite the first gear 84. Rotation of the second gear 88 about the pivot axis 90 causes the rotation of the associated housing 92, gate lever 96, and second gate member 42 in connection therewith. Rotation moves the second gate member 42 in an approximate radial arc about the second pivot axis 90 to a rest position. The rest position occurs, in the exemplary embodiment, when a gate member 42 is placed in contact with the gate receptor 38, 98 on the first and/or second rail section 12, 16. In the example provided, the second gate member 42 moves into mating position in the gate receptor 38 and may simultaneously engage a mating portion 98 of the second rail section 16. Movement of the second gate member 42 occurs, such that it does not interfere with the first gate member 40 or respective assembly. Thus, in the exemplary embodiment, the first gate 40 moves in an approximate radial motion below the second gate member 40. Furthermore, as a result of the position of the axis 90 of rotation of the second gear assembly 30, the second gate member 40 approaches the rail section 12 and the gate receptor 38 at least partially from a side of the rail, although a degree of motion may extend above the rail section. Rotation of the first and second gear assemblies 28, 30 in the opposite direction causes the disengagement of the second gate member 42 and engagement of the first gate member 40 with the gate receptor 38 on the first rail section 12, in the same manner.
Positioning of the second pivot axis 90 below the first pivot axis 70 of the respective gear assemblies, or positioning of the second pivot axis 90 below the plane 72 of the rail section provides significant advantages. For instance, the second pivot axis provides a lower travel path, and the approximate side-action of the gate reduces, if not eliminates, interference with the trolley, pusher dogs and/or drive chain. In other words, as the second gate member approaches the rail section at least partially from a side thereof, it may avoid the trolley, pusher dogs and chain.
The switch assembly 10 of an exemplary embodiment may also or alternatively be provided with trolley stop assembly 20. As shown in FIGS. 3 and 16-17, the trolley stop assembly 20 in the illustrated embodiment is carried by the second rail section 16, and may be provided in an on-center or near on-center position. Trolley stop assembly 20 may be formed of a body 108 including one or more of a first side plate 110, a second side plate 112, a pivot member 114, a trolley stop member 116, and a weight or weighted member 118.
Accordingly, as shown in
As indicated and shown in
The pivot pin or member 114 is formed of a rod or bolt or other suitable device. The pivot pin 114 extends through the first side plate 110 and the first end 120 of the rail section 16, and may further extend through the second side plate 112. A nut or other attachment mechanism may be used to secure the pivot member 114 in place, although such an attachment mechanism may not be required.
The stop member 116 is carried by a portion of the side plates 110, 112 and in the exemplary embodiment is positioned adjacent or on a first portion 134 of the plates. As can be seen in
The weighted member 118 for use with the trolley stop 20 is formed by a weighted device sufficient to move the trolley stop 20 from a first position to a second position. In an exemplary embodiment, the weight is sufficient to pivot the trolley stop 20 about the pivot axis 140 of the pivot member 114 to a “trolley stop” position illustrated in dashed lines in
The foregoing assembly may be formed of any suitable materials for use with conveyor assemblies. In an exemplary embodiment, any one or more of the components of the conveyor assembly, trolley stop assembly or rails described herein may be formed of metal, such as stainless or galvanized steel, aluminum, and the like, as well as plastics, composites, and combinations of any of the foregoing. The components may be integrally formed, or formed separately and connected together, such as by welding, adhesive, tongue and groove, fasteners, and the like.
The trolley stop assembly 20 may be formed by positioning the first and second side plates 110, 112 on first and second sides 150, 152 of the rail 16 and inserting the pivot member 114 through the apertures 142 in the central portion 138 of the side plates 110, 112 and into the end portion 120 of the second rail. The stop member 116 may be attached to the upper or first portion 134 of the side plates and the weighted member 118 may be attached to the lower or second portion 136 of the side plates in the manner previously described. While a specific arrangement and order of assembly is described, the forgoing is provided by way of example only, and any suitable arrangement or order may be acceptable for purposes of the present invention. For example, the stop member 116 and weighted member 118 may be attached to the side plates 110, 112 prior to placing the side plates in connection with the second rail section 16.
Accordingly, in an exemplary embodiment of making and assembling the gear switch 10 and trolley stop 20, a first rail section 12 and a second rail section 16 are provided. A switch assembly 10 may be formed by attachment of a first gear assembly 28 and a second gear assembly 30 to one or more transfer plates 48, 50. The transfer plates may be attached to the first rail section 12. At least one and preferably two gate members 40, 42 may also be provided. Gate members 40, 42 may be attached to the gear assemblies 28, 30 as described in detail hereinabove. A trolley stop 20 may be connected to an end 120 of the second rail section 16 by pivot member 114. The first rail 12 and second rail section 16 may also be connected by attachment of a bridge 18.
In operation of the exemplary embodiment of the trolley stop assembly 20, the weighted member 118 and stop member 116 pivot about the pivot member 114 in response to gate member 42 interaction with the second rail section 16. For example, the second gate member 42 may be positioned such that it is in mating relation with the second rail section 16. In this position, the stop member 116 is positioned such that it does not interfere with trolley 26 movement. Upon operation of the switch assembly 10, which may occur by manual or automated means, the second gate member 42 may be lifted from the gate receptor 98 of the second rail section 16. Free of the gate member 42, which retains the trolley stop member 20 in the position described hereinabove, the weighted member 118 pivotally moves about the pivot axis 140, raising a portion of the stop member 116 above the top portion 124 of the second rail section 16 so as to engage or prevent movement of a trolley 26 there beyond. When the second gate member 42 is lowered again, the gate member 42 presses upon the trolley stop 20 along a portion 148 of the stop member 116 or side plates, causing pivotal movement of the trolley stop assembly 20 in the opposite direction until the gate member 42 reaches its rest position and the stop member 116 is positioned in alignment with the top of the second rail 16.
Unlike traditional trolley stops, which are often positioned to the side of the rail, the use of first and second side plates, and thus, the centralized positioning of the rail section in relation to the pivotal or more specifically, weighted pivotal movement of the trolley stop assembly, permits the trolley stop assembly to rotate smoothly without binding. Furthermore, this positioning enables or enhances the engagement and disengagement of the gate member with the trolley stop, providing consistent non-binding movement and ease of operation.
Presently preferred embodiments of the invention and many of its improvements have been described with a degree of particularity. The previous description is of preferred examples for implementing the invention, and the scope of the invention should not necessarily be limited by this description. Although various representative embodiments of this invention have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of the inventive subject matter set forth in the specification and claims. All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, angled, and so forth) are only used for identification purposes to aid the reader's understanding of the embodiments of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention unless specifically set forth in the claims. Joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other.
This application is a continuation of U.S. patent application Ser. No. 12/185,505, filed on Aug. 4, 2008, entitled GEAR SWITCH FOR A CONVEYOR ASSEMBLY, the contents of which is hereby incorporated in its entirety by reference.
Number | Date | Country | |
---|---|---|---|
Parent | 12185505 | Aug 2008 | US |
Child | 12711778 | US |