GB2148827A - Conveyor apparatus - Google Patents

Abstract

A conveyor mechanism comprises a fixed rail oriented for example in helical fashion to present straight side portions and curved end portions. The rail forms first and second pairs of second support surfaces (26, 32 and 28, 30). A conveyor chain is mounted on the rail and includes first and second pairs of freely rotatable support wheels (46-52) arranged to engage the first and second pairs of support surfaces, respectively, to form pairs of interfacing planes therewith. The planes of each pair of interfacing planes form therebetween an included angle (AD, BC) of less than 180 DEG , preferably 90 degrees. The wheels engage the support surfaces exteriorly of those included angles. The support surfaces disposed along the side and end portions of the helix are straight and curved in cross-section respectively. A plurality of product-supporting carriers (80) are mounted to the conveyor chain. A plurality of trays are connected to the chain and are situated between the carriers and the chain to catch droppings from the product being conveyed. The trays comprise rigid plates which overlap at their adjacent ends. Pan guides (190) are releasably attachable to the trays for providing lateral stability for pans carried by the conveyor. <IMAGE>

Description

SPECIFICATION Conveyor apparatus The present invention relates to conveying and, in particular, to the conveying of bakery of dough products through a baking oven.

It is conventional to conduct certain products, such as bakery goods, for example, through a chamber wherein the environment (e.g., temperature, humidity, etc.) is controlled. In the case of bakery goods, such a chamber may comprise an oven or proofer, for example, wherein the goods are conveyed for an extended period upon a helically arranged conveyor.

Commonly, the conveyor may comprise an endless chain which travels within or upon a track, and a series of support carriers which carry the bakery goods are connected to and above the chain by means of connecting brackets. In order to support the outer lateral edges of the carriers and stabilize the chain, it has been proposed to position stationary runners beneath the carrier. However, such runners add cost to the system and restrict the accessibility of the conveyor chain for maintenance and may result in metal to metal contact directly over bakery products below.

It has also been proposed to mount a conveyor chain within a rail such that a plurality of wheels on the chain engage a plurality of internal surfaces of the rail, as in Figure. 9 of U.S. patent No. 3,834,708 issued to Kambera on January 27, 1976. However, in the event that the conveyor is subjected to torsional forces tending to rotate the chain about the longitudinal axis thereof, the wheels can become jammed within the rail.

It is therefore, an object of the invention to minimize or obviate problems of the type described above.

Another object is to provide a novel conveying apparatus which provides for improved stability against torsional loading without the need for stationary runners under the outer lateral edges of the carriers.

An additional object is to provide a novel conveying apparatus which avoids any tendency for the conveyor chain to become jammed againstthe rail.

Another object is to prevent droppings from the product being conveyed from fouling the conveyor rail and wheel bearings.

Afurther object is to provide an easily releasable and insertable pan guide for laterally stabilizing pans being conveyed.

Summary of the invention These objects are achieved by the present invention which involves a conveyor apparatus comprising a rail and a conveyor chain mounted thereon.

The rail comprises first and second pairs of support surfaces. The conveyor chain includes first and second pairs of freely rotatable support wheels arranged to engage the first and second pairs of support surfaces, respectively, to form pairs of interfacing planes therewith. The planes of each pair of interfacing planes form therebetween an included angle of less than 180 degrees. The wheels engage the support surfaces exteriorly of the included angles. As a result, there is little tendency for the wheels to become jammed against the rail in the event that the conveyor chain is rotated torsionally under the weight of the load it is carrying.

Preferably, the rail is arranged in helical fashion and includes straight side portions and curved end portions. The support surfaces disposed along the side portions straight in cross-section. The support surfaces disposed along the end portions may be curved in cross-section.

The conveyor chain preferably comprises a plurality of links interconnected by a plurality of coupling members. Each of the coupling members is pivotably connected to successive links about pivot axes which are mutually oriented at a 90 degree angle.

Each ofthe links is preferably formed offourwalls fixedly interconnected at right angles relative to one another. A plurality of connecting arms is connected to the links, and a plurality of product carriers is connected to the connecting arms. A plurality of trays is connected to the connecting arms and situated beneath the product carriers and the conveyor chain to catch droppings from the product being conveyed. The trays comprise rigid plates which overlap along the longitudinal axis of the conveyor chain. The overlapping portions are spaced apart vertically. Each tray includes a stepped end which overlaps an adjacent end of the next tray.

Pan guides are releasably attachable to the trays and are configured to extend above the carriers. The pan guides fit within cavities of the pans being conveyed so as to provide lateral stability of the pans.

The drawings The objects and advantages of the invention will become apparent from the following detailed description of preferred embodiments thereof, in connection with the accompanying drawings, in which like numerals designate like elements, and in which; Figure lisa plan view of a baking chamber, with a portion of a roof of the chamber removed to expose a conveyor-supporting rail system, the conveyor being omitted for clarity; Figure 2 is a side view of a the baking chamber, with a side wall thereof removed to expose the interior of the chamber; Figure 3 is a plan view of a conveyor which is to be mounted on the rail, the rail being omitted for clarity; Figure 4 is a side elevational view of a portion of the conveyor; Figure 5 is a cross-sectional view taken through the conveyor along the line 5-5 of Figure 4;; Figure 6 is a view similar to Figure 5 taken at a point of the rail system where a straight side portion merges with a curved end portion and wherein the rail support surfaces change from being straight in cross-section to curved in cross-section; Figure 7 is a side elevational view of a driving mechanism for the conveyor; Figure 8 is a cross-sectional view of the conveyor driving mechanism taken along line 8-8 in Figure 7; and Figure 9 is a cross-sectional view taken through an alternative embodiment of the conveyor chain.

Detailed description ofpreferred embodiments of the invention A baking oven 10 depicted in Figures 1 and 2 comprises an enclosure 12 in which a conveyorsupporting framework 14 is disposed. The conveyor supporting framework 14 is configured to support a conveyor 16 (Figure 6) to travel in helical fashion within the oven. The conveyor, which is omitted from Figures 1, 2 for clarity, carries products to be baked, such as pans of dough products, i.e., bread loaves or rolls. A suitable heating system maintains the oven at a desired baking temperature.

The framework 14 carries a helical rail system 18 up on which the conveyor 16 is supported. The rail system forms a plurality of straight side runs 20 and curved end portions 22 which interconnect the side runs 20.

Although the rail system is continuous, it is shaped differently along the side runs 20 and end portions 22. Along the side runs the rail, as depicted in Figure 5, may comprise a metal channel 24 bent to form a series of flat guide surfaces 26, 28,30,32.

There are two such surfaces located to each side of the longitudinal axis 34 of the tube 24. Thus, one pair of surfaces 28,30 is located to each side of the longitudinal axis 34 of the tube 24. That is, one pair of surfaces 28, 30 is located to one side and the other pair of surfaces 26, 32 is located to the other side. As will become apparent from the subsequent description, planes A, B, C, D are defined by the interfacing between the surfaces 26-32 and a plurality of support wheels 46,48,50, 52 of a chain portion 42 of the conveyor 16, which wheels engage the surfaces to form the interfacing planes. Respective pairs B,C and A,D of those planes form included angles BC and AD therebetween, which angles are less than 180 degrees and preferably, are each 90 degrees.A pair of the wheels 48,50 engage the pair of surfaces 28,30, and the other pair of wheels 46, 52 engage the other pair of support surfaces 26, 32. The wheels 46-52 engage those surfaces 36-42 along the exterior of the angles BC, AD, that is, the wheels are located to the outside of the included acute angles BC and AD.

Along the curved portions, the rails may be circular cylindrical configuration as depicted in Fi gure 6. which shows the transition zone between the flat rail surfaces and the cylindrical rails. A pair of circular cylinders 60, 62 have their opposite ends attached to the tubes 24 of successive side runs. The wheels 46-52 of the conveyor chain 42 engage the curved outer surfaces 64,65,66,67 of the cylinders.

Planes A', B', C', D' are defined by the interfacing between the surfaces 64-67 and the wheels 42-52, which interfacing planes are tangent to the cylinders 60, 62 at the point of wheel contact. The planes form included angles B'C' and A'D' therebetween, with the wheels engaging the surfaces 64-67 along the outside of such angles. The angles B'C' and A'D' are each less than 180 degrees, preferably, 90 degrees.

Since the wheels engage the outer surfaces of the rail, it is assured that the wheels cannot become jammed in response to a torsional turning of the conveyor in direction 76, as can occur in cases where wheels engage inside surfaces of a rail as in U.S.

Patent 3,934,708, for example. The planes A-D are aligned with respective planes A'-D' so that the wheels 46-52 travel smoothly from the surfaces 26-36 and onto the surfaces 64-67.

The conveyor 16 includes a chain 69 which is formed of temperature-resistant metal and comprises a plurality of links 70 which are interconnected by a plurality of shorter coupling members 72. The links 70 are rectangular in cross-section (Figure 6), i.e., each link is formed of four perpendicular walls 74 which are rigidly attached to one another, e.g., by welding. Such a link configuration provides substantial resistance to deformation in a torsional direction 76 (Figure 7) relative to the longitudinal axis 34 as might tend to be caused by the weight of products carried by the conveyor. In that regard, carriers 80 are rigidly connected to the links 70 by means of U-shaped connecting arms 82 which project upwardliy from the links 70.The carriers 80 are elongate in the lateral direction, i.e., the carriers 80 extend laterally in both directions from the longitudinal axis 34 (Figure 5). Thus, product which is placed onto the carrier and which exerts a moment upon the chain will impose torsional forces in the direction 76 upon the chain 42. That moment is resisted by the links 70 and by the metal support wheels 46-52. The support wheels 46-52 are each mounted on the coupling members 72 for rotation about axes 90 which mutually intersect at the longitudinal axis 34 of the conveyor chain. Thus, the reaction forces exerted by the track surfaces against the wheels, which forces extend perpendicularly to the rotary axes, will create a reaction moment having, as a moment arm, an imaginary line extending from the longitudinal axis perpendicularly to the reaction force.Thus, two substantial resisting moments will be created at diametrically opposed wheels (i.e., wheels having colinear axes of rotation) to resist rotation of the conveyor chain in either direction about the longitudinal axis undertheweight of the products being conveyed. Furthermore, torsional deformation of the carrier links about the longitudinal axis under that same weight is effectively resisted by the inherent strength of the four-sided wall structure of the carrier links.

Each coupling member 72 is pivotably connected to adjacent carrier links 70 by pivot pins 92, 94 oriented perpendicularly to one another. Preferably, the coupling member 72 is connected to a leading link 70 by a vertical pivot pin 92, thereby forming a universal type pivot coupling which enables the leading and trailing links 70 and their carriers 80 to swing vertically and horizontally relative to one another during travel throughout the conveying path.

The carriers 80 are of a grid-type configuration in that they are each formed of metal support rods 100 which are oriented mutually parallel in a fore-aft direction, and a pair of lateral connecting rods 102.

The connecting rods 102 are connected to the U-shaped connecting arms 82 by suitable fasteners such as bolts. Successive carriers 80 are spaced apart in the fore-aft direction.

Front and rear ends of the support rods 100 are bent downwardly and rearwardly to form curved leading and trailing edges 104,106 which form minimal obstruction to the introduction of product thereonto.

Disposed between the conveyor chain 42 and the carriers 80 are a series of rigid heat-resistant metallic trays 110 which are adapted to catch crumbs which may fall from the dough product, and thereby prevent those crumbs from fouling the rails and wheel bearings and impeding conveyor travel.

The trays 110 are connected to the connecting arms 82 and are positioned so as to remain below the product support surfaces 112 defined by the rods 100. Leading and trailing ends of adjacent trays 110 are arranged in vertical overlapping relationship above the coupling members 72. Preferably, the trailing end of each tray is stepped upwardly at 114 to extend over a leading end 116 of the next tray 110.

This vertically spaced relationship allows the trays to swing relative to one another in the vertical direction along with the respective carriers and links.

An alternate form of wheel arrangement is de picted in Figure 9, wherein wheels 120, 122, 124, 126 engage a four-sided rail 128. The wheel surfaces 130 are offrusto-conical shape. Pairs of the wheels 120, 126 and 122, 124 are rotatably mounted on common parallel axles 132, 136 which depend from the carrier 138. If desired, two additional pairs of wheels may be mounted on the carrier 138. It will be appreciated that the four point engagement between the wheels and the rail provides for stabilized travel of the conveyor. Also, since the wheels engage outside surfaces of the rails, the conveyor wheels cannot become jammed, as noted earlier. The rail support surfaces 140, 142 in Figure 9 are depicted as forming a 90 degree angle therebetween, but other angles can be used.

The conveyor 16 is driven in any suitable manner.

For example, an endless drive chain 150 (Figure 7) can be provided which is positioned beneath the conveyor 16. The drive chain 150 is wrapped around a pair of sprockets 152,154, one of which 152 is driven by a take-off 156 from a suitable motor (not shown). The chain comprises a plurality of links 159 which carry a series of drive lugs 160. The lugs are connected to the links by pivot pins 162 which interconnect some of the links. A pair of guide wheels 164 are mounted on those pins 162, the wheels 164 being adapted to travel within a stationarty track 166 located along an upper working run of the drive chain 150.

A pair of auxiliary wheels 168 are rotatably mounted on the lugs behind the guide wheels 164, but are not connected to the links 159. Thus, when the lug 160 travels off the guide track 166, the auxiliary wheels swing downwardly, i.e., the lug rotates about the pin 162 (see the right-hand lug 160' in Figure 7). As the lugs 160 travel along the working run, they engage push surfaces 170 of the coupling members 72 to advance the conveyor. When the lug leaves the guide track 166 and swings downwardly, the lug breaks-off contact with the associated push surface 170. This occurs just before the lug traverses the front sprocket 152. The auxiliary wheels 168 swing downwardly into abutment with a hub 172 which is mounted on the sprocket axle 174. The auxiliary wheels ride upon the hub 172 as the lug traverses the front sprocket 152.Eventually, upon reaching the rear sprocket 154, the auxiliary wheels engage a guide surface 176, which constitutes an extension of the guide track 166, and rides upwardly along that surface 176 in a curved path toward the working run.

It may be desirable to provide lateral stability for products which are being carried upon the carrier grids 80. For example, in the case of baking bread, the dough is carried in pans. To prevent the pans from sliding laterally, a plurality of pan guides 190 (Figure 5) are removably securable to the trays 112.

Each pan guide is formed of metal, e.g., a curved metal rod 192 which carries two pairs of depending spring feet 194. Each pair of feet are adapted to be inserted into longitudinally spaced holes 196 (Figure 3) in the associated tray 112. Each foot 194 has a recess 198 which receives an edge of the hole to releasably retain the pan guide 190 in place. That is, as the pairs of feet 194 are pushed into the holes 196, the feet are initially urged together by the side edges of the holes 196, and then rebound outwardly when the recesses 198 become alinged with such side edges. The pan guides 190 are adapted to fit into standard cavities in the bottoms of pans to limit alteral movement of the pans.

IN OPERATION, products to be baked are conveyed upon the conveyor 16 in a helical path within the baking chamber. The products are supported on the carriers 80 which, in turn, are carried by the chain 69. The wheels 46-52 of the chain are supported upon the straight surfaces 26-32 (Figure 5) during travel along the side portions 20 of the helical travel path, and upon the curved surfaces 64-67 (Figure 6) during travel along the end portions 22 of the helical travel path. The wheels are supported externally of the angles BC, AD formed by the support surfaces to resist, in a jam-free manner, turning of the conveyor about the longitudinal axis 34 under the weight of the product being conveyed. The four-sided construction of the links also aids in resisting such turning motion.

Crumbs or the like which fall from the product are caught by the trays 110 and thus do not foul the rails.

The overlapping relationship between adjacent ends of the trays permits free swinging movement between the links of the chain.

The pan guides provide lateral stability for pans disposed upon the carriers.

Although the present invention has been described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, modifications, substitutions, and deletions not specifically described, may be made, without departing from the spirit and scope of the invention.

Claims (26)

1. A conveyor apparatus comprising: rail means comprising first and second pairs of support surfaces, and a conveyor chain mounted on said rail means and including first and second pairs of freely rotatable support wheels arranged to engage said first and second pairs of support surfaces, respectively, to form pairs of interfacing planes therewith, said planes of each pair of interfacing planes forming therebetween an included angle of less than 180 degrees, said wheels engaging said support surfaces exteriorly of said included angles.

2. A conveyor apparatus according to claim 1, wherein said included angle is 90 degrees.

3. Aconveyorsystem according to claim 1, wherein said surfaces of one of said pair of surfaces are parallel to respective surfaces of the other of said pair of surfaces.

4. A conveyor system according to claim 1 including a plurality of carriers connected to said conveyor chain above said wheels.

5. A conveyor system according to claim 1, wherein two of said wheels are mounted for rotation about a common first axis, and the other two wheels are mounted for rotation about a common second axis.

6. A conveyor system according to claim 1, wherein said rail means is helically arranged.

7. A conveyor apparatus according to claim 2, wherein said rail means includes straight side portions and curved end portions, said support surfaces along said side portions being straight in crosssection, and said support surfaces along said end portions being curved in cross-section.

8. A conveyor apparatus according to claim 2, wherein said conveyor chain comprises a plurality of links interconnected buy a plurality of coupling members, each of said coupling members being pivotably connected to successive links about pivot axes which are mutually oriented at a 90 degree angle.

9. A conveyor apparatus according to claim 1, wherein said links are formed of four walls fixedly interconnected at right angles relative to each other.

10. A conveyor apparatus according to claim 1 including connecting arms connected to said links, a plurality of product carriers connected to said connecting arms.

11. A conveyor apparatus according to claim 10 including a plurality of trays connected to said connecting arms and situated between said product carriers and said conveyor chain to catch droppings from the product being conveyed.

12. A conveyor apparatus according to claim 11 including pan guides releasably attachable to said trays and configured to extend above said carriers.

13. A conveyor apparatus according to claim 11, wherein said trays comprise rigid plates which overlap along the longitudinal axis of said conveyor chain, the overlapping portions being spaced apart vertically.

14. A conveyor apparatus according to claim 13, wherein each tray includes a stepped end which overlaps an adjacent end of the next tray.

15. A conveyor apparatus according to claim 1, wherein said connecting arms define the sole means of support for said carriers.

16. A conveyor apparatus comprising: rail means extending in a helical path to define straight side portions and curved end portions, said rail means comprising first and second pairs of support surfaces, a conveyor chain mounted on said rail means and comprising: a plurality of links which comprise four walls joined at right angles, a plurality of coupling members interconnecting successive pairs of said links by means of pivots oriented 90 degrees to one another, and first and second pairs of freely rotatable support wheels mounted on each coupling member and arranged to engage said first and second pairs of support surfaces, respectively, to form interfacing planes therewith, each said pair of interfacing planes forming an included angle of 90 degreestherebe- tween, said wheels engaging said surfaces exteriorly of said included angles, and a plurality of product carriers connected to said links and spaced thereabove, said chain defining the sole means of support for said carriers.

17. A conveyor system according to claim 16, wherein two of said wheels are mounted for rotation about a common first axis, and the other two wheels are mounted for rotation about a common second axis.

18. A conveyor apparatus according to claim 16, wherein said rail means includes straight side portions and curved end portions, said support surfaces along said side portions being straight in crosssection, and said support surfaces along said end portions being curved in cross-section.

19. A conveyor apparatus according to claim 16 including a plurality of trays connected to said chain and situated below said carriers and above said chain.

20. A conveyor apparatus according to claim 19, including pan guides releasably attachable to said trays and configured to extend above said carriers.

21. A conveyor apparatus according to claim 19, wherein said trays comprise rigid plates which overlap along the longitudinal axis of said conveyor chain, the overlapping portions being spaced apart vertically.

22. A conveyor apparatus according to claim 20, wherein each tray includes a stepped end which overlaps an adjacent end of the next tray.

23. Aconveyorapparatus comprising: rail means, a conveyor chain including a plurality of interconnected links mountedfortravel on said rail means, said chain including wheels mounted on said rail means, connecting arms extending upwardly from at least some of said links, product carriers mounted on said connecting arms and defining product support surfaces for carrying a product to be conveyed, and a plurality of trays disposed beneath said product support surfaces for catching droppings from the product, said trays comprising a plurality of stiff plates fixedly mounted to said conveyor chain so as to be disposed between said conveyor chain and said product support surfaces in overlying relationship to said conveyor chain, each plate having a stepped configuration at least at one end thereof so as to be vertically spaced in overlapping relationship to the adjacent end of a successive plate.

24. A baking oven comprising: an enclosure surrounding a baking chamber, a conveyor apparatus arranged for travel in said baking chamber and comprising: rail means extending in a helical path to define straight side portions and curved end portions, said rail means defining first and second pairs of support surfaces which have a straight cross-section along said side portions and a curved cross-section along said curved portions, a conveyor chain mounted on said rail means and including:: a plurality of links, a plurality of coupling members interconnecting successive pairs of said links by means of pivots oriented 90 degrees to one another, and first and second pairs of freely rotatable support wheels mounted on each coupling member and arranged to engage said first and second pairs of support surfaces, respectively, to form interfacing planes therewith, each said pair of interfacing planes forming an included angle of 90 degrees therebetween, said wheels engaging said surfaces exteriorly of said included angles, and a plurality of product carriers connected to said links and spaced thereabove, said chain defining the sole means of support for said carriers.

25. A conveyor for carrying containers, comprising: a chain having support wheels adapted to engage a guide rail, a plurality of container support carriers mounted to said chain and spaced thereabove, said carriers being open at their centers, a plurality of trays carried by said chain and positioned below a container-carrying surface defined by an associated carrier and above said chain to intercept particles falling from the product being carried in the containers, and container guides releasably mounted in said trays and projecting above said container-support surfaces to fit into cavities of the containers to limit lateral movement thereof.

26. A conveyor apparatus constructed and arranged for use and operation substantially as described herein with reference to the accompanying drawings.