Hygienic magnetic tray and conveyor

Patent metadata

Field	Value
Publication number	US-10654660-B2
Application number	US-201815884556-A
Country	US
Kind code	B2
Filing date	Jan 31, 2018
Priority date	Jan 31, 2018
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

A hygienic magnetic tray and conveyor. The low-profile tray includes a forcer sandwiched between an article-supporting top and an opposite bottom. The top is made of hygienic material, and the bottom can be made of a low-friction material. The tray is propelled along a guide surface on an enclosure housing stator coils supported in a conveyor frame. The stator forms a linear motor with the forcer in the tray. Various disposal systems provide escape routes for removing fluids and debris from the guide surface of the stator enclosure.

First claim

What is claimed is:

1. A conveyor tray comprising:
a top made of a first material and including an upper article-supporting face;
a bottom made of a second material and attached to the top;
a forcer between the top and the bottom;
wherein the top and the bottom are separate pieces; and
wherein the forcer includes one or more magnet arrays magnetized with a predetermined field pattern after the top and the bottom are attached.

2. A conveyor tray as in claim 1 wherein the top and the bottom are co-molded around the forcer.

3. A conveyor tray as in claim 1 wherein the top is overmolded onto the bottom and the forcer.

4. A conveyor tray as in claim 1 wherein the first material is a first plastic material and the second material is a different second plastic material.

5. A conveyor tray as in claim 4 wherein the first plastic material is a hygienic material such as polyethylene terephthalate (PET, or PETE), high-density polyethylene (HDPE), or polystyrene (PS).

6. A conveyor tray as in claim 4 wherein the second plastic material is a low-friction material such as polyoxymethylene (POM, acetal), polypropylene (PP), or ultra-high-molecular-weight polyethylene (UHMW).

7. A conveyor tray as in claim 1 wherein the one or more magnet arrays are plastic magnet arrays.

8. A conveyor tray as in claim 1 wherein the forcer comprises four magnet arrays arranged in first and second pairs of parallel magnet arrays wherein the first pair is orthogonal to the second pair.

9. A conveyor tray as in claim 1 wherein the one or more magnet arrays are arranged in a checkerboard pattern.

10. A conveyor tray as in claim 1 wherein the bottom has a concave lower face.

11. A conveyor tray as in claim 1 further comprising front and rear ends and left and right sides and a skewed skirt extending outward from each of the front and rear ends and each of the left and right sides.

12. A tray conveyor comprising:
a tray including a top and a bottom and a forcer between the top and the bottom;
a conveyor frame having first and second sides;
a first tray rail supported in the conveyor frame along the first side and a second tray rail supported in the conveyor frame along the second side to limit the lateral excursion of the tray;
a linear-motor stator supported in the conveyor frame;
a stator enclosure housing the linear-motor stator supported in the conveyor frame;
a top guide surface supported in the conveyor frame under the tray;
wherein the linear-motor stator propagates an electromagnetic wave along the length of the conveyor frame that interacts with the forcer in the tray to propel the tray in a conveying direction along the conveyor frame on or over the top guide surface; and
wherein a disposal system is provided to provide egress through which the tray pushes fluids or debris from the top guide surface.

13. A tray conveyor as in claim 12 wherein the disposal system includes discontinuities in the top guide surface and the stator enclosure providing the egress through which fluids or debris can escape from the top guide surface.

14. A tray conveyor as in claim 12 wherein the disposal system includes through holes extending through the top guide surface and the stator enclosure providing the egress through which fluids or debris can escape from the top guide surface.

15. A tray conveyor as in claim 12 wherein the disposal system includes gaps in the first and second tray rails providing the egress through which fluids or debris can escape from the top guide surface.

16. A tray conveyor as in claim 12 wherein the disposal system includes vertical supports spaced apart along the conveyor frame supporting the first and second tray rails above the level of the top guide surface to form a gap between each of the first and second tray rails and the top guide surface providing the egress through which fluids or debris can escape from the top guide surface.

17. A tray conveyor as in claim 16 further comprising springs connected between the conveyor frame and the vertical supports lightly biasing the first and second tray rails toward the tray so that debris pushed to the first or second side by the tray widens the gap by forcing the first or second tray rail away from the tray against the spring bias.

18. A tray conveyor as in claim 16 wherein the width of the top guide surface and the stator enclosure is less than the distance between the first and second tray rails and the width of the tray.

19. A tray conveyor comprising:
a tray including a top and a bottom and a forcer between the top and the bottom;
a conveyor frame having first and second sides;
a linear-motor stator supported in the conveyor frame;
a stator enclosure housing the linear-motor stator supported in the conveyor frame;
a top guide surface supported in the conveyor frame under the tray;
wherein the linear-motor stator propagates an electromagnetic wave along the length of the conveyor frame that interacts with the forcer in the tray to propel the tray in a conveying direction along the conveyor frame on or over the top guide surface; and
wherein the top guide surface and the stator enclosure include through holes to drain fluids and debris.

20. A tray conveyor as in claim 19 wherein the through holes are elongated slots.

21. A tray conveyor as in claim 20 wherein the elongated slots are elongated in the conveying direction.

22. A tray conveyor as in claim 20 wherein the elongated slots are elongated perpendicular to the conveying direction.

23. A tray conveyor as in claim 22 wherein the elongated slots include first slots extending inward from the first side of the conveyor frame past the centerline of the top guide surface and second slots extending inward from the second side of the conveyor frame past the centerline of the top guide surface and wherein the first slots alternate with the second slots in the conveying direction.

24. A tray conveyor as in claim 19 wherein the through holes are cruciform in shape.

25. A tray conveyor as in claim 19 wherein the top guide surface is convexly crowned and the bottom of the tray is concavely contoured to complement the top guide surface.

26. A tray conveyor as in claim 19 wherein the linear-motor stator includes ironless cores.

27. A tray conveyor as in claim 19 wherein the conveyor frame includes an inverted-L-shaped tray rail along each of the first and second sides of the conveyor frame and extending over the tray to retain the tray by limiting vertical excursion of the tray and horizontal excursion of the tray perpendicular to the conveying direction.

28. A tray conveyor as in claim 19 further comprising position sensors housed in the stator enclosure at spaced apart positions in the conveying direction to detect the presence of a tray at the spaced apart positions.

29. A tray conveyor as in claim 19 wherein the linear-motor stator housed in the stator enclosure comprises a first stator extending along the first side of the conveyor frame and a second stator extending along the second side of the conveyor frame and wherein the forcer in the tray includes a first magnet array close to the first stator and a second magnet array close to the second stator.

30. A tray conveyor as in claim 19 wherein:
the conveyor frame includes:
a first section;
a second section perpendicular to the first section

Assignees

• Laitram Llc

Inventors

• Ragan Bryant G
• Khurana Shuchi P
• Landrum John F
• Mehendale Aditya
• Nijsse Gerard Johannes Pieter
• Sahin-Nomaler Funda
• Reijnders Silvester Matheus
• Van Der Laan Ewout Peter

Classifications

• B65G2207/26

  Hygienic features, e.g. easy to sanitize · CPC title

• B65G54/02

  electrostatic, electric, or magnetic · CPC title

• B65G2201/0202

  Agricultural and processed food products · CPC title

• B65G45/10 Primary

  Cleaning devices (adaptations of roller sleeves for cleaning belts B65G39/073) · CPC title