Scraper assembly

Certain embodiments of the present invention provide a scraper assembly. For example, in one embodiment, a scraper assembly comprises: a substantially rigid member; a pin with a first end and a second end, wherein a tab protrudes from a side of the first end and the second end is attached to the substantially rigid member; a scraper head with a hole therethrough that is large enough to receive the pin, wherein the scraper head has a first channel that runs the depth of the scraper head and is large enough to receive the tab, and wherein the scraper head has a second channel that does not run the depth of the scraper head and is large enough to receive the tab; and a coil spring, wherein the coil spring is disposed around the pin and is held captive between the substantially rigid member and the scraper head.

BACKGROUND OF THE INVENTION

The technology of the present invention generally relates to scraper assemblies and methods for assembling scraper assemblies. Particularly, the present technology relates to scraper assemblies used in commercial blending and/or cooking systems and methods for assembling such scraper assemblies.

Commercial blending and/or cooking systems are known in the food preparation industry and other industries. For example, U.S. Pat. No. 4,733,607 (the “'607 patent”), which issued to Star et al. on Mar. 29, 1988, and is entitled Food Processing Machine, describes “[a] mixer for food products and the like in commercial quantities [that] comprises a horizontally elongated body with a trough bottom in which rotates one or more horizontal drive shafts carrying an agitator in the form of a helical ribbon or worm of a radius matching that of the trough bottom. The ribbon supports a number of scraper units on it, each scraper unit including a scraper body having a broad face facing toward the trough bottom, the broad face terminating in two opposed relatively sharp edges. The scraper bodies are mounted for rocking movement so that the leading edge will be forced into scraping engagement with the trough bottom and will remain in engagement with the trough bottom even though the trough is wavy or uneven. Either of the edges of the scraper body can be the leading edge, depending on the direction of rotation of the agitator drive shaft.” ('607 patent at Abstract.)

In another example, U.S. Pat. No. 5,228,775 (the “'775 patent”), which issued to Horn et al. on Jul. 20, 1995, and is entitled Reversing Blender Agitators, describes “[i]mproved methods of operating batch or continuous blenders having tub and two agitators extending parallel to each other, each agitator having horizontal shaft and agitator ribbon wound helically around the shaft.” ('775 patent at Abstract (references to Figures omitted).) The '775 patent further states, “The agitators are rotated in opposite directions to fold the product into the center of the tub for mixing, with both agitators moving the product in the same direction lengthwise in the tub. The agitators' rotation direction is periodically reversed, with the time of reversed operation in each cycle being less than the time of forward operation, so that the product as a whole progressively moves toward discharge end of the blender as the product is being mixed. When needed, scrapers are attached to the agitator ribbons to scrape the wall of the tub upon rotation of the agitators in either direction.” ('775 patent at Abstract (references to Figures omitted).)

Although scraper assemblies that are currently available provide a certain degree of effectiveness, they have shortcomings. For example, currently available scraper assemblies allow for potential contamination and/or reduced productivity. Particularly, currently available scraper assemblies have spaces where food can get stuck, and may not be readily removed without deconstructing the scraper assembly. This can result in the contamination of new food items with remnants of previously processed food items and/or reduced productivity due to an increased need for system maintenance, such as removal and cleaning of scraper assemblies, which oftentimes requires special tools, such as a torque wrench.

Further, some scraper assembly designs have many discrete parts that can come loose and eventually become mixed in with food items. This creates the potential for downstream contamination in systems that feed into larger repositories as well as the potential to damage equipment used in commercial blending and/or cooking systems.

Finally, scraper assembly designs known in the art do not sufficiently maintain contact between scraper heads and the inner surface of tubs, which results in uneven scraping and increased sticking of substances, such as food items, to the inner surface of tubs.

Thus, there is a need for an improved scraper assembly for use in commercial blending and/or cooking systems. Particularly, for a scraper assembly that reduces the risk of contamination, scrapes tubs more evenly and allows for easier removal and/or replacement of scraper assembly components.

BRIEF SUMMARY OF THE INVENTION

Certain embodiments of the present invention provide a scraper assembly for use in a blending system and a method for assembling a scraper assembly. For example, in one embodiment, a scraper assembly for use in a blending system comprises: a substantially rigid member; a pin with a first end and a second end, wherein a tab protrudes from a side of the first end and the second end is attached to the substantially rigid member; a scraper head having at least one scraping surface, wherein the scraper head has a hole therethrough that is large enough to receive the pin, wherein the scraper head has a first channel that runs the depth of the scraper head and is large enough to receive the tab, and wherein the scraper head has a second channel that does not run the depth of the scraper head and is large enough to receive the tab; and a coil spring, wherein the coil spring is disposed around the pin and is held captive between the substantially rigid member and the scraper head.

As another example, one embodiment of a blending system comprises: a tub having an inner surface; an agitator having a shaft and a ribbon wound helically around the shaft, wherein the agitator is disposed within the tub such that the agitator can be rotated about the shaft without contacting the inner surface of the tub; and a scraper assembly comprising: a substantially rigid member, wherein the substantially rigid member is attached to the ribbon; a pin with a first end and a second end, wherein a tab protrudes from a side of the first end and the second end is attached to the substantially rigid member; a scraper head having at least one scraping surface, wherein the scraping surface contacts the inner surface of the tub, wherein the scraper head has a hole therethrough that is large enough to receive the pin, wherein the scraper head has a first channel that runs the depth of the scraper head and is large enough to receive the tab, and wherein the scraper head has a second channel that does not run the depth of the scraper head and is large enough to receive the tab; and a coil spring, wherein the coil spring is disposed around the pin and is held captive between the substantially rigid member and the scraper head.

As another example, one embodiment of a method for assembling a scraper assembly comprises: providing a substantially rigid member with a pin attached thereto, wherein the pin has a tab protruding from a side of the end of the pin that is not attached to the substantially rigid member; providing a coil spring; winding the coil spring onto the pin by winding the coil spring around the tab until the coil spring is held captive between the substantially rigid member and the tab; providing a scraper head having at least one scraping surface, wherein the scraper head has a hole therethrough that is large enough to receive the pin, wherein the scraper head has a first channel that runs the depth of the scraper head and is large enough to receive the tab, and wherein the scraper head has a second channel that does not run the depth of the scraper head and is large enough to receive the tab; aligning the scraper head with the pin such that the tab is aligned with the first channel; sliding the scraper head onto the pin, thereby compressing the coil spring, until the tab passes through the scraper head; aligning the scraper head with the pin such that the tab is aligned with the second channel; and releasing the scraper head, thereby allowing the coil spring to decompress.

The foregoing summary, as well as the following detailed description of embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, certain embodiments are shown in the drawings. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

FIGS. 1-3illustrate embodiments of an agitator6and scraper assemblies8used in accordance with the present technology.FIG. 1is a perspective view of one embodiment of an agitator6and scraper assemblies8;FIG. 2is a side view of one embodiment of an agitator6and scraper assemblies8; andFIG. 3is an end view of one embodiment of an agitator6and scraper assemblies8.

In the embodiments shown inFIGS. 1-3, the agitator6includes a cylindrical shaft10, spokes12and a ribbon14. The shaft10, spokes12and ribbon14are preferably made of steel, but can also be made of other materials with steel-like characteristics. The ribbon14is wound helically around the shaft10and attached thereto by the spokes12. The spokes12are attached to the shaft10and are also connected to the ribbon14. The shaft10, spokes12and ribbon14are preferably attached by welding.

In the embodiments shown inFIGS. 1-3, an agitator6can be used in connection with a tub, a vat or other container to blend substances. From this point on, any reference herein to a tub is also a reference to a vat or other container. Specifically, the agitator6can be rotated about the shaft10in order to rotate the spokes12and ribbon14, thereby blending substances in a tub (not shown). For example, in one embodiment, a tub is a food receptacle and the substances to be blended are food items. Substances that are blended in a tub can stick to the inner surface of the tub, that is, the surface of the tub that contacts the substances that are being blended. Also, such sticking can be enhanced by the heating or cooling of the inner surface of the tub. Thus, it is desirable to scrape the inner surface of a tub during blending in order to remove substances that stick to the inner surface of the tub.

Examples of systems in which agitators can be used with tubs to blend substances include systems such as those described in U.S. Pat. No. 4,733,607, which issued to Star et al. on Mar. 29, 1988 and is entitled Food Processing Machine, and U.S. Pat. No. 5,228,775, which issued to Horn et al. on Jul. 20, 1995 and is entitled Reversing Blender Agitators.

In the embodiments shown inFIGS. 1-3, the scraper assemblies8are attached to the agitator6. Specifically, the scraper assemblies8are attached to the ribbon14by a substantially rigid member16. The substantially rigid member16is preferably welded to the ribbon14of the agitator6. The substantially rigid member16is preferably attached to the ribbon14such that the substantially rigid member16is substantially parallel to the shaft10of the agitator6. Further, each scraper assembly8, as shown, includes a scraper head18. The scraper head18is preferably configured to contact the inner surface of a tub (not shown). In various embodiments, a substantially rigid member that extends from a ribbon of an agitator, which agitator includes a shaft and a ribbon, is not substantially parallel to the shaft of the agitator. In such embodiments, the remaining components of the scraper assembly are configured such that the scraper head contacts the inner surface of a tub.

In the embodiment shown inFIG. 2, the scraper heads18are spaced such that, together, they span a distance x. In a preferred embodiment, the distance x is equal to the distance covered by the ribbon14. In a preferred embodiment, the distance x is also equal to the length of a tub (not shown). The spacing of the scraper heads18, as shown inFIG. 2, allows the entire distance x to be scraped once for every full rotation of the agitator6in either direction a or direction b. When the agitator6is rotated in direction a or direction b, the scraper heads18can rock somewhat, which can allow the scraper heads18to maintain contact with the inner surface of a tub (not shown).

The embodiment shown inFIG. 2, has five scraper assemblies8. In a preferred embodiment using five scraper assemblies, each scraper head18is about eight inches long and about two inches wide. In various embodiments, any number of scraper assemblies may be employed to cover a given distance. That is, the shorter the scraper heads, the more scraper assemblies that will be required to cover the same distance. Likewise, the longer the scraper heads, the fewer scraper assemblies that will be required to cover the same distance. Scraper heads need not be eight inches long and two inches wide and scraper heads need not be proportioned such that the length is four times the width. That is, scraper heads can come in any length and width that is sufficient for a given application. For example, it may be desirable to vary scraper head length and/or width based on what substances are being blended and/or the size of a tub. In various embodiments, scraper heads of different sizes can be used for a given application.

In the embodiment shown inFIG. 3, the scraper heads18protrude beyond the ribbon14. It is preferred that the scraper heads18, and not the ribbon14, contact the inner surface of a tub (not shown). The clearance between the ribbon14and a tub (not shown) can vary due to imperfections in the inner surface of a tub. Likewise, the distance the scraper head18protrudes beyond the ribbon14can vary with the actual clearance between the ribbon14and a tub (not shown). For example, in one embodiment, the scraper head18protrudes about 3/16 of an inch beyond the ribbon14and, thus, there is about 3/16 of an inch of clearance between the ribbon14and the tub (not shown). In such an example, the clearance between the ribbon14and the tub (not shown) can vary, thereby becoming greater and/or less than 3/16 of an inch, due to imperfections in the inner surface of the tub. In such an example, when the clearance between the ribbon14and the tub (not shown) becomes greater than 3/16 of an inch, the scraper head18can deflect in a direction x, thereby decompressing a spring20, in order to maintain contact with the tub (not shown). In such an example, when the clearance between the ribbon14and the tub (not shown) becomes less than 3/16 of an inch, the scraper head18can deflect in a direction y, thereby compressing a spring20, in order to maintain contact with the tub (not shown). In various embodiments, the clearance between a ribbon14and a tub can be greater or less than 3/16 of an inch.

FIGS. 4-6illustrate embodiments of scraper assemblies used in accordance with the present technology.FIG. 4is a perspective view of a scraper assembly;FIG. 5is a side view of a scraper assembly; andFIG. 6is a bottom view of a scraper assembly. In the embodiments shown inFIGS. 4-6, a scraper assembly8includes a substantially rigid member16, a scraper head18, a coil spring20, a pin22and a keeper24. The substantially rigid member16is attached to the pin22. The substantially rigid member16is preferably welded to the pin22. The substantially rigid member16is preferably attached to the pin22such that the pin22is substantially perpendicular to the substantially rigid member16. The keeper24is attached to the pin22. The keeper24is preferably welded to the pin22. The keeper24is preferably attached to the pin22such that the keeper24is substantially parallel to the substantially rigid member16(shown inFIG. 4) and both ends of the keeper24protrude beyond the outer wall of the pin22(shown inFIG. 6).

In the embodiment shown inFIG. 5, the coil spring20is held captive between the scraper head18and the substantially rigid member16. In this embodiment, the coil spring20is not fully decompressed (not in its fully relaxed state). That is, the coil spring20would decompress further (to its relaxed state) if the coil spring20were not held captive between the scraper head18and the substantially rigid member16. Thus, the coil spring20is exerting a force on the scraper head18. Further, in the embodiment shown inFIG. 5, the coil spring20is not fully compressed. That is, if a force is exerted on the scraper head18in direction y, the scraper head18will deflect in direction y, thereby further compressing the coil spring20. Thus, when a scraper head18contacts the inner surface of a tub (not shown), and the scraper head18deflects, the scraper head18exerts a force on the inner surface of the tub (not shown).

In various embodiments, the amount of force that a scraper head18exerts on the inner surface of a tub (not shown) can be changed by using a spring with a different spring constant. The deflection also allows the scraper head18to maintain contact with the inner surface of a tub (not shown) despite imperfections in the inner surface of the tub (not shown).

FIG. 7is an exploded view of one embodiment of a scraper assembly8used in accordance with the present technology. As shown inFIG. 7, the scraper assembly8includes a substantially rigid member16, a pin22, a keeper24, a coil spring20and a scraper head18.

In the embodiment shown inFIG. 7, the substantially rigid member16has a hole26therethrough. The hole26is configured to receive the pin22. The hole26is preferably circular to receive a cylindrical pin22. In various embodiments, the hole can be any shape and the pin can be any corresponding shape. In other embodiments, a substantially rigid member can have a space therein, such as a slot, groove, or other indentation, to receive a pin that does not pass completely through the substantially rigid member. In another example, the substantially rigid member can be solid and the pin can be welded to the surface of the substantially rigid member.

In the embodiment shown inFIG. 7, the pin22is a cylinder with a first end27and a second end28with a channel30therethrough. The first end27of the pin22is inserted into the hole26and attached to the substantially rigid member16. The pin22is preferably welded to the substantially rigid member16. The pin22is preferably attached to the substantially rigid member16such that the pin22is substantially perpendicular to the substantially rigid member16.

In the embodiment shown inFIG. 7, the keeper24is a member that fits inside the channel30. The keeper24preferably fits inside the channel30such that the top32of the keeper24and the top34of the pin22create a flat surface. The keeper24preferably fits inside the channel30such that the ends of the keeper24protrude beyond the sides of the pin22, thereby forming tabs at one end of the pin. The keeper24can be attached to the pin22. The keeper24is preferably attached to the pin22by welding.

In various embodiments, a pin and keeper can be a unitary member. In such embodiments, the unitary member is a pin with at least one tab protruding from a side of one end of the pin. In various embodiments, the unitary member can be configured such that any number of tabs protrude from a side of one end of the pin.

In various embodiments, a substantially rigid member, a pin and a keeper can be a unitary member. In such embodiments, the unitary member is a bar (round or flat) with a pin protruding substantially perpendicular to the length of the bar, and the pin has at least one tab protruding from a side of the end of the pin that is furthest from the bar. In various embodiments, the unitary member can be configured such that any number of tabs protrude from a side of the end of the pin that is furthest from the bar.

In various embodiments, a ribbon of an agitator, a substantially rigid member, a pin and a keeper can be a unitary member. In such embodiments, the unitary member is a helically wound ribbon with a bar (round or flat) extending therefrom that has a pin protruding substantially perpendicular to the length of the bar, and the pin has at least one tab protruding from a side of the end of the pin that is furthest from the bar. In various embodiments, the unitary member can be configured such that any number of tabs protrude from a side of the end of the pin that is furthest from the bar.

In the embodiment shown inFIG. 7, the coil spring20can be wound onto the pin22by twisting the coil spring20around the protruding ends of the keeper24, akin to twisting a key onto a key chain. Once the coil spring20is wound onto the pin22, the coil spring20is held captive between the substantially rigid member16and the protruding ends of the keeper24. The coil spring20is preferably made of steel, but can also be made of other materials with steel-like characteristics. In other embodiments, the coil spring20can be slid onto the pin22prior to attaching the pin22to the substantially rigid member16. In such an embodiment, once the pin22is attached to the substantially rigid member16, the coil spring20is held captive between the substantially rigid member16and the protruding ends of the keeper24.

In the embodiment shown inFIG. 7, the scraper head18preferably has two scraping edges36that run the length of the scraper head18. The scraper head18can be configured such that the scraping edges36provide scraping in two directions. In various embodiments, the scraper head18can have a single scraping edge. In such embodiments, the scraper head18can be configured such that the scraping edge provides scraping in one direction.

In the embodiment shown inFIG. 7, the scraper head18has a hole38therethrough. The hole38is large enough to receive the pin22, but not large enough to receive the coil spring20. On two sides of the hole38(180 degrees apart—around the circumference of the hole38), there are channels40that run the depth of the scraper head18. On another two sides of the hole38(180 degrees apart—around the circumference of the hole38), there are channels42that do not run the depth of the scraper head18. As shown inFIG. 7, the channels40that run the depth of the scraper head18are 90 degrees apart (around the circumference of the hole38) from the channels42that do not run the depth of the scraper head18. In various embodiments, channels that run the depth of a scraper head with a hole therethrough need not be 90 degrees apart (around the circumference of the hole therethrough) from channels that do not run the depth of a scraper head. In such embodiments, other degrees of separation are sufficient to allow the scraper head to be attached to the rest of the scraper assembly.

In various embodiments, the scraper head can be modified to accommodate any number of tabs protruding from the pin, that is, a corresponding channel that runs the depth of the scraper head and a corresponding channel that does not run the depth of the scraper head can be included in the hole therethrough for each tab.

In the embodiment shown inFIG. 7, the scraper head18is attached to the rest of the scraper assembly by aligning the channels40that run the depth of the scraper head18with the protruding ends of the keeper24. The scraper head18is then slid toward the substantially rigid member16, thereby compressing the coil spring20, until the protruding ends of the keeper24pass all the way through the scraper head18. The scraper head18is then turned 90 degrees such that the channels42that do not run the depth of the scraper head18are aligned with the protruding ends of the keeper24. The scraper head18is then allowed to slide away from the substantially rigid member16, thereby allowing the coil spring20to decompress, until the protruding ends of the keeper24contact the end of the channels42that do not run the depth of the scraper head18.

In the embodiment shown inFIG. 7, the scraper head18is removed from the rest of the scraper assembly by sliding the scraper head18toward the substantially rigid member16, thereby compressing the coil spring20, until the protruding ends of the keeper24pass all the way through the scraper head18. The scraper head18is then turned 90 degrees such that the channels40that run the depth of the scraper head18are aligned with the protruding ends of the keeper24. The scraper head18is then allowed to slide away from the substantially rigid member, thereby allowing the coil spring20to decompress, until the protruding ends of the keeper24are removed from the scraper head18.

In the embodiment shown inFIG. 7, once the scraper head18is removed, the coil spring20can be removed by winding the coil spring20off the pin22by twisting the coil spring20around the protruding ends of the keeper24, akin to twisting a key off of a key chain.

In the embodiment shown inFIG. 7, once the coil spring20and the scraper head18are removed from the rest of the scraper assembly, the rest of the scraper assembly can be cleaned and/or a new coil spring and/or scraper head can be attached to the rest of the scraper assembly.

FIGS. 8-10illustrate embodiments of a scraper head18used in accordance with the present technology.FIG. 8is a perspective view of one embodiment of a scraper head18;FIG. 9is a bottom view of one embodiment of a scraper head18; andFIG. 10is a top view of one embodiment of a scraper head18.FIGS. 8-10show aspects of a scraper head18that are discussed with regard toFIG. 7. For example, the channels40that run the depth of the hole38are shown in bothFIG. 9(bottom view) andFIG. 10(top view), however, the channels42that do not run the depth of the hole38are shown inFIG. 9(bottom view), but notFIG. 10(top view).

In the embodiments shown inFIGS. 8-10, the scraper head18is preferably made of nylon. In various embodiments, scraper heads can be made of other materials, including but not limited to, other types of plastics. One such example is Peek, a commercially available brand of plastic that is manufactured by Victrex plc, a company with manufacturing plants and research facilities in the UK and sales and distributions centers worldwide. Peek, for example, can be used in scraper heads that are utilized in high temperature environments. Scraper heads can also be made of metals, such as steel or other materials with steel-like characteristics, and then coated with plastic, for example.

FIG. 11is a perspective view of one embodiment of agitators6and scraper assemblies8disposed within a tub60.FIG. 12is a top view of one embodiment of agitators6and scraper assemblies8disposed within a tub60. InFIGS. 11 and 12, two agitators6are disposed next to each other within a tub60. In other embodiments, any number of agitators can be used depending upon the size of the tub. In the embodiments shown inFIGS. 11 and 12, the inner surface of the tub60conforms at least in part to the general cylindrical shape of the agitators6. This embodiment can be used with the preferred embodiment described above in connection withFIGS. 2 and 3.