Belt cleaner system and method

A snap-fit scraper blade is provided for being snap-fit onto a mounting pole. The scraper blade has a blade body including an upper scraping portion and a lower mounting portion. The lower mounting portion has depending legs with inner surfaces that are configured for snap-fitting the scraper blade body onto a square mounting pole.

BACKGROUND OF THE INVENTION

There are known belt cleaners that employ a scraper blade which is molded directly onto the pole, which eliminates gaps between the blade and the pole. However this method has many disadvantages. The blade is not replaceable, so once it wears out the entire blade and pole must be replaced. Also, these belt cleaners are not easily tailored to the width of the conveyor and the belt, because the blade is molded to a specific width and cannot be cut shorter without damaging the pole.

Prior belt cleaner systems have used round poles, which by nature do not have any horizontal surfaces for debris to collect.

Prior belt cleaner systems for snap-fit conveyor belt cleaner blades have used a round pole which has a key bar projecting upwardly therefrom and a corresponding key-way in the blade body to prevent rotation of the blade relative to the pole. The key bar is a separate piece which requires a mating groove to be machined into the pole. The key bar is then permanently glued or welded in place and creates another interface which can harbor bacteria and is difficult to clean.

Other conveyor belt cleaners in the market use pins to attach the blade to the pole.

Competitive products have used secondary collars or stop features to prevent migration of the blade relative to the pole, which can be difficult to clean or could potentially contain hardware which could become loose and end up in the product.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

This invention pertains to a scraper blade (FIG. 1) for a light duty conveyor belt cleaner (FIGS. 2-5) which attaches to the pole of the cleaner in a snap-fit fashion. The pole is an elongate member which spans the distance between the two opposing sides of a conveyor structure and is generally parallel to the conveyor belt surface. In one embodiment the pole is a 1″×1″ steel tube. The blade is snap fit onto the pole by first arranging the blade to be partially engaged with the pole, and then rotating the blade relative to the pole to achieve a snap fit. The blade is configured so that once it is in snap fit engagement on the pole it is able to resist the torsion forces applied to it as the tensioner mechanism applies a torque to the pole for urging the scraper blade against the belt surface. Additionally the blade is configured such that it can be removed (disengaged from its snap-fit) from the pole by imparting a torsion force on the blade that is in the opposite direction to the normal torsion forces experienced by the blade when in operation. In this manner, the blade can resist the torsion forces experienced during operation yet still be easily removed from the pole for cleaning or replacement.

The blade may be made from a single material or multiple materials, such as UHMW or a Rigid PVC/Urethane combination. It may also be made in multiple sizes to accommodate different diameter head pulleys.

Special considerations must be taken into account when designing products that are to be used in food processing. Due to the high risk of bacteria growth, food processing equipment must be cleaned and sanitized regularly. For this reason it is beneficial for the equipment to be designed in such a way that minimizes the opportunity for bacteria growth and maximizes the clean-ability of the equipment. One way to make a piece of equipment easier to clean is to make it very easy to disassemble. Another way is to minimize the number of areas for bacteria to grow and make these areas “open” so that they are easier to clean.

The scraper blade discussed above improves the clean-ability of the conveyor belt cleaner because it is very quick and easy to install and remove. When it is time to clean the conveyor system (FIGS. 6-8), the cleaner can then be quickly disassembled and its components sprayed down or submerged in a tub of cleaning solution.

The geometry of the scraper blade minimizes the number of places for debris to collect and areas for bacteria to grow. This is achieved by orienting the flat faces of the square pole at approximately a 45 degree angle to the horizon, such that the legs of the blade body which are adjacent to the surfaces of the pole form inclined faces which do not permit debris to collect as easily. It is also extruded from a single piece, which is more easily cleaned than some competitive blades which are made from individual segments butted together thereby forming interfaces between each blade segment.

Additionally, the blade is designed to be snap-fit onto a square pole so that it resists rotation of the blade relative to the pole without the addition of keys and corresponding keyways or other anti-rotation devices which can make the pole more difficult to clean.

The snap-fit is also beneficial because it does not require the use of pins or other hardware to retain the blade on the pole, which could otherwise potentially become loose and end up in the conveyed product (food).

The legs of the scraper blade5may be oriented at an acute angle to one another (FIG. 1A), thereby forming an inwardly biased force and a positive engagement once the cleaner blade is in snap-fit engagement with the square pole. In doing so, sufficient is friction is generated between the pole and the blade to substantially minimize or eliminate axial migration of the blade relative to the pole during use.

As can be best seen inFIG. 1A, the blade body10has an upper belt scraping portion10ahaving a tip end for engaging a conveyor belt50(FIGS. 6-8) and a lower pole mounting portion10b. The lower portion10bincludes a downstream leg12that extends at an acute angle to upstream leg14between respective upper portions16and18thereof, and specifically substantially flat, inclined inner surfaces16aand18aof the upper portions16and18of the respective legs12and14. In this manner, when snap-fit on square pole20, the resilient legs12and14are splayed apart from each other causing them to tightly grip on corresponding inclined pole downstream and upstream surfaces22and24.

As previously mentioned, the blade is rotatably snap-fit onto the pole20. For this purpose, the downstream leg12has a lowermost, enlarged gripping portion26that includes a substantially flat, inclined inner surface28extending generally orthogonal to the inner surface16afor engaging corresponding lower, downstream inclined surface30of the square pole20(FIG. 3). Similarly, the upstream leg18has a lowermost gripping portion34that includes a substantially flat, inclined inner surface35extending generally orthogonal to inner surface18afor engaging corresponding lower, upstream inclined surface31of the square pole20(FIG. 5). In addition, the enlarged bottom leg portion26has a lowermost guide or cam surface32that extends at an outward incline from the bottom of the inner surface28. The legs12and14at their respective lowermost portions26and34are spaced from each other to form an opening40therebetween for fitting the square pole20between the legs12and14as described below.

For connecting the blade to the pole, the guide surface32is engaged with and pushed along the upper, downstream inclined pole surfaces22causing the leg12to begin to resiliently flex away from the leg14with the tip end34aof its lowermost gripping portion34engaged with the upper, upstream inclined pole surface24. With the leg cam surface32engaged on pole surface22, the blade can be rotatably snap-fit onto the pole20with the tip end34arotated to clear the corner between the upstream orthogonal surfaces24and31of the pole20, and the juncture between the blade body surfaces28and32clearing the corner between the downstream orthogonal surfaces22and30of the pole20.