TECHNICAL FIELD

The present invention relates to systems and methods for cleaning the working surface of conveyor belts; more particularly, to systems and methods for cleaning soft or fabric conveyor belts as may be used, for example, in the continuous baking arts; and most particularly to such a conveyor belt cleaner system employing steam, a plurality of wipers, and vacuum, and preferably being disposed on the underside of a conveyor belt system for cleaning the belt working surface during the return pass of the belt.

BACKGROUND OF THE INVENTION

The present invention is directed to the art of cleaning the working surface of a conveyor belt.

In the prior art, conveyor belts used in various commercial activities are known to become soiled, typically with spillage from materials being conveyed or treated on the belt. It becomes desirable and necessary from time to time to clean at least the working surface of the belt. This is conveniently accomplished by installing a cleaning device in the path of the belt and allowing the belt to pass through the cleaning device, perhaps several times, if necessary, until the extraneous material is removed.

Conveyor belts may be divided into two categories, a) discontinuous chain-type belts formed of discrete metal or plastic elements in an articulated surface, and b) continuous belts formed of a flexible material such as plastic or fabric. The present invention is directed to systems for cleaning the working surface of a continuous conveyor belt.

In the prior art, U.S. Pat. No. 9,248,975 B2, issued Feb. 2, 2016 to Handy, discloses and claims “cleaning apparatus including a frame which includes end parts each mountable in a position adjacent a respective side edge of a conveyor to be cleaned, a cleaning unit selectively locatable to extend between the end parts to clean the conveyor, the cleaning unit being selectively movable when extending between the two end parts, between a rest position clear of the conveyor, and an in use position engaging with the conveyor, the frame also including a cross part extending between the end parts, wherein the cross part includes a pair of transverse guides, with which guides side edges of the cleaning unit are slidably engageable when moving to or from a position extending between the end parts”. The cleaning unit is held in place in the use position by two over-center latches, one at each end.

A shortcoming of this system is that both over-center latches must be released to move the cleaning unit from the use position to the rest position and also to remove the cleaning unit from the frame. A further shortcoming is that the required pair of transverse guides adds an undesirable level of complexity to the structure of the frame. A still further shortcoming is that both the steam or cleaning solution feed and the vacuum extraction engage their respective transverse chambers through an end of the unit, rather than the center, such that the distribution of both cleaning solution and vacuum extraction are not symmetrically distributed across the width of the conveyor belt.

U.S. Pat. No. 10,954,077 B1, issued Mar. 23, 2021, to Yoo, discloses and claims “a conveyor belt cleaning apparatus . . . operating in a pneumatic manner using compressed air without using electricity. The conveyor belt cleaning apparatus uses a rodless cylinder so as to enable the steam spray nozzle to perform a reciprocating motion . . . ”.

A shortcoming of this system is that a transversely reciprocating cleaning system cannot clean equally all areas of a moving substrate unless the speed of reciprocation is much greater than the speed of the substrate past the system.

U.S. Pat. No. 10,507,986 B2, issued Dec. 17, 2019, to Rogan, discloses and claims a conveyor belt cleaning apparatus comprising a belt scraper and an air knife. Unlike the present invention, the apparatus of Rogan does not employ steam to assist in the removal of food particles from the conveyor belt.

U.S. Pat. No. 10,836,586 B2, issued Nov. 17, 2020, to Schmidgall, discloses and claims a conveyor belt cleaner system comprising a pair of backing rollers for supporting an inverted conveyor belt and a scraper blade urged by springs again the belt surface to be cleaned. Unlike the present invention, the apparatus of Schmidgall does not employ steam to assist in the removal of food particles from the conveyor belt.

The present invention is directed to a system for cleaning the working surfaces of continuous conveyor belts formed of a flexible material such as plastic or fabric, using application of steam, surface wipers, and vacuum. Prior art cleaning systems are intended for use on a conveyor belt of a specified width, wherein the steam is distributed at substantially the full width of the belt. However, a common problem arises when applying a system designed for a first belt width to cleaning of a belt having a second and narrower width wherein the steam application occurs on both the belt surface and on the fixed conveyor frame and belt backing elements outboard of the moving belt. Such steam overspray results in undesirable condensation and water pooling on conveyor frame surfaces outboard of the belt, which eventually requires corrective measures which may include stopping the conveyor and the cleaning process to mop up the excess water.

This problem is solved by the apparatus disclosed and claimed in the parent application, wherein the width of steam application may be adjusted to accommodate belts of various widths, thereby making such a system significantly more versatile than prior art belt cleaning systems. The present invention applies the technology of the parent application to a continuous conveyor belt surface at a portion of the return path of the belt wherein the belt, and necessarily the cleaning apparatus, are inverted with respect to the system disclosed in the parent application.

SUMMARY OF THE INVENTION

In some applications, it can be desirable to be able to clean a conveyor belt at a position on its return path rather than on its forward path. Accordingly, the present invention adapts the concepts disclosed and claimed in the parent application to a configuration wherein both the conveyor belt to be cleaned and the cleaning mechanism are inverted with respect to the arrangement disclosed and claimed in the parent application.

The present invention is directed to a conveyor belt cleaner system, comprising:

1. first and second mounting plates attachable to opposite sides of a frame of a belt conveyor;

2. a backing platen subassembly and a pair of backing rollers positioned transversely of the conveyor belt between the first and second mounting plates and disposed behind a return length of the conveyor belt to be cleaned;

3. a bottom tray subassembly disposed between the first and second mounting plates;

4. a steam and vacuum cleaning subassembly disposed in the bottom tray subassembly comprising a first chamber defining a steam chamber transversely disposed under the conveyor belt to be cleaned and opening upwards, wherein the first transverse chamber is provided with a transverse steam header connectable to a source of steam; a second chamber defining a vacuum chamber adjacent the first chamber and transversely disposed under a second portion of the length of conveyor belt to be cleaned, wherein the second transverse chamber is operable under sub-atmospheric pressure and is provided with a suction outlet connectable to a source of vacuum, and wherein the first conveyor belt portion becomes the second conveyor belt portion by passage of the first portion from the first chamber into the second chamber; a first wiper disposed in the first chamber transversely of and in wiping contact with the first portion of the length of conveyor belt to be cleaned; a second wiper having a discontinuous wiping surface and defining a transverse septum between the first and second chambers; and a third wiper disposed in the second chamber transversely of and in wiping contact with the second portion of the length of conveyor belt to be cleaned; and apparatus being cooperative with the steam header to vary the width of steam application from the steam header onto the conveyor belt in accordance with a width of conveyor belt presented to the conveyor belt cleaner system. The steam and vacuum cleaning subassembly is provided with adjustable feet, preferably four at the four corners thereof and resting on the bottom of the box frame. Preferably the wipers are mounted on springs to ensure continuous wiping of the conveyor belt surface as the blade of the wiper becomes worn.

