TECHNICAL FIELD

Present disclosure generally relates to a cane shredder device, more particularly relates to a shredder hammer providing a self-sharpening feature for the hammer tip.

BACKGROUND OF THE DISCLOSURE AND PRIOR ARTS

Cane or sugar cane raw material is shredded or cut into small parts in order to extract juice from the cane. The cane shredder devices prepare the cane before sugar extraction for increasing crush rates. Therefore, cane shredding becomes an important process in the cane milling process. Typically, the shredding action by the cane shredders exposes more fiber particles, rupturing more sucrose bearing cells and allowing the mill or diffuser extraction process to maximize the extraction of juice from the cane. During the shredding operation, the cane is subjected to a hammer action, where the cane is crushed by the hammer against an anvil plate of the cane shredder device. In the entire equipment of the cane shredder device, typically the wearable part is a hammer tip. Life cycle of the hammer tip can vary from a few days to a few weeks, and therefore, the hammer tip may require to be replaced or replenished a number of times during the sugar plant operation.

Existing hammers in the cane shredder device are provided with a replaceable hammer tip or a weld-able tip. One kind of existing hammer tip of the hammer is shown in FIGS. 1 and 2. The hammer (100’) consists of a hardened single piece construction (01), which can be brazened on a soft material (02) and fixed on the hammer (100’). Geometry of the hardened part of the hammer can be of numerous shapes prevalent in the market. However, these hammers (100’) are associated with non-desirable issues like, providing new tips with sharp edge due to gradual blunting after some usage and time. Also, as the tip gets worn out gradually, the tip performance may decrease. The shredder equipment in which hammers with such tips are installed, may draw more power as the tips get blunt or worn out. This in turn may deteriorate the quality of output product as the hammer tips gets worn out.

One kind of design of shredder hammer for the cane shredding device available in the market is a weldable hammer, where the hammer tips are welded with hardened welding electrode. One type of weldable hammer tip is disclosed in a patent number AU2003261479B2 (hereinafter referred to as the Pat ’479). The hammer in the Pat ’479 consists of a tip having a mild steel base with a spigot releasably engageable in a socket in the head of the hammer. A white iron laminate is vacuum brazed to the top of the mild steel base. Four tungsten-carbide tiles are fixed to the white iron laminate or mild steel base via a tri-ply foil. The tri-ply foil is a composite foil of a copper layer coated on both sides with silver, and when heated to 650°C, the silver wets the bases of the tungsten-carbide tiles and the white iron laminate.

Another kind of design of shredder hammer for the cane shredding device available in the market is a replaceable hammer tip. One such type of replaceable hammer tip is proposed in the U.S. Patent No. 6,131,838A (hereinafter referred to as the Pat ’838). The Pat ’838 discloses a number of methods of mounting hardened tip onto the hammers. Further, a hammer tip in the Pat ’838 is provided with a centrally located bolt hole for receiving a bolt for releasable securement to a hammer. The hammer tip includes a front face having a working edge, and a back portion with two opposing shoulder sections with a recessed section therebetween. The hammer includes a support shoulder for receiving the bottom of the hammer tip. Together, the shoulder sections, the recess formed between, and the support shoulder create a saddle-back for releasable integration with the hammer.

Yet another kind of replaceable hammer tip has been proposed in the U.S. Patent publication no. 20150314298A1 (hereinafter referred to as the Pat ’298). The Pat ’298 discloses a multi-piece shredder hammer for use in a reducing machine. The multi-piece shredder hammer includes a base mounted onto the reducing machine. A replaceable tip is mounted to the base and to impact the material to be reduced. The hammer also includes a retainer to secure the replaceable tip to the base. The replaceable tip is installed on the base from a side of the base.

Still another kind of replaceable hammer tip has been proposed in the U.S Patent no. 2534301A (hereinafter referred to as the Pat ’301). The Pat ’301 discloses an impact hammer for rotary pulverizers. A replaceable tip is joined by a tongue groove connection which is constructed such that centrifugal force acting on the tip tends to wedge the tip onto the arm increasingly during normal use of the hammer. The hammer includes engaging shoulders or ledges for contact with tongues of the tip. In order to fasten the tip on the arm and to positively lock it in place, a bolt is provided which is received in a bore drilled into the leading edge of the hammer arm.

Although there are many design proposed in the hammers, the tips of the hammers have shortcoming such as, wearing of the hammer tip. Therefore, it requires replacement or replenishment a number of times during the sugar plant operation. Present invention is directed to overcome the shortcoming of the existing designs.

SUMMARY OF THE DISCLOSURE

In an embodiment of the present disclosure, a self- sharpening shredder hammer is provided. The self-sharpening shredder hammer comprises a hammer body having a first end adapted to be pivotally connected to a shaft of a motor, a plurality of faces and a flange at a second end. The flange at the second end has a plurality of grooves. The self- sharpening shredder hammer further comprises a first set of strips disposed onto grooves provided on the flange at the second end of the hammer body. The self- sharpening shredder hammer further comprises a second set of strips disposed onto the grooves not provided with the first set of strips. The second set of strips are adapted to wear at a faster rate than the first set of strips, thereby exposing fresh edges of the first set of strips for shredding, achieving the self- sharpening feature. In an embodiment, a retainer plate is disposed on an exterior portion of either side of an assembly of the first set of strips and the second set of strips for holding them together at the second end of the hammer body.

In an embodiment, the flange is provided with a plurality of holes on two of the opposing faces not provided with the grooves, for connecting the retainer plate with the hammer body through fasteners for holding the first set of strips and the second set of strips together.

In an embodiment, the grooves are provided on two of opposing faces of the plurality of faces not provided by the plurality of holes.

In an embodiment, the first set of strips and the second set of strips are having a C shaped body, having a central plate and a pair of arms extending from ends of the central plate.

In an embodiment, the arms of the first set of strips and the second set of strips are adapted to be seated in the grooves.

In an embodiment, the second set of strips are having 25-75 % smaller width when compared with width of the first set of strips.

In an embodiment, the second set of strips are having hardness ranging 18 - 40 HRC and the first set of strips are having hardness ranging 55 - 60 HRC or more.

In an embodiment, the first set of strips and the second set of strips are held together with each other through bolt clamping or any one of fabrication method of brazing, electro-fusion and a chemical solution.

In an embodiment, the flange at the second end of the hammer body is widened, to enable accommodation of more number of the first and second set of strips, when compared with number of the first and second set of strips accommodated on the flange.

In an embodiment, the first set of strips is disposed onto the grooves provided on the flange at the second end of the hammer body such that at least one strip of the second set of strips is present in between the two strips of the first set of strips.

In an embodiment, a plurality of self- sharpening shredder hammer is provided in a cane shredder device for shredding cane or sugar cane.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The above and other features, aspects, and advantages of the subject matter will be better understood with regard to the following description and accompanying drawings:

FIG. 1 shows a line sketch of an existing cane shredder hammer;

FIG. 2 shows a line sketch of hammer tip of the cane shredder hammer shown in

FIG. 1;

FIG. 3 shows a line sketch view of a self- sharpening hammer according to an exemplary embodiment of the present disclosure;

FIG. 4 shows an exploded view of the self- sharpening hammer shown in FIG. 3;

FIG. 5A shows a line sketch of a hammer tip of the self-sharpening hammer shown in FIGS. 3 and 4 in a top view;

FIG. 5B shows a line sketch of the hammer tip of the self-sharpening hammer shown in FIGS. 3 and 4 in a side view; FIG. 5C shows a line sketch of the hammer tip of the self-sharpening hammer shown in FIGS. 3 and 4 in a front view;

FIG. 6 shows an enlarged view of the top view of the hammer tip shown in FIG. 5A;

FIG. 7A shows an isometric view of the hammer body having a straight flange shown in FIGS. 3 and 4, according to an exemplary embodiment of the present disclosure;

FIG. 7B shows an isometric view of a hammer body having an integral widened flange according to another exemplary embodiment of the present disclosure; and

FIG. 7C shows an isometric view of a hammer body having a welded widened flange according to another exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE WITH REFERENCE TO ACCOMPANYING DRAWINGS

Provided below is a non-limiting exemplary embodiment of the present invention and a reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts. Moreover, references to various elements described herein, are made collectively or individually when there may be more than one element of the same type. However, such references are merely exemplary in nature. It may be noted that any reference to elements in the singular may also be construed to relate to the plural and vice-versa without limiting the scope of the disclosure to the exact number or type of such elements unless set forth explicitly in the appended claim(s).

One objective of the invention disclosed in the present disclosure is to provide a hammer tip which is cost effective yet ensuring uniform performance of the equipment (shredding hammer device) throughout the life cycle of the hammer tip, uniform power consumption of the equipment throughout the life cycle of hammer tip, and economical when compared with the existing shredding hammers.

The cane shredding hammer of the present invention has self-sharpening edges. The self- sharpened edges have the advantages such as, but not limited to, achieving same or constant performance throughout the life cycle of the tip, achieving same or a constant power consumption of the equipment (shredder) throughout the life cycle of the tip, and achieving uniform output quality of the shredded cane, and not deteriorated with life cycle of the tip.

FIGS. 3 and 4 illustrate a line sketch view and an exploded view of a self- sharpening hammer (100) respectively, according to an exemplary embodiment of the present disclosure. The term “self-sharpening shredder hammer” and the term “hammer” are interchangeably used in the disclosure. It is to be understood that both the terms relate to a same device and it is used for brevity. The hammer (100) in the illustrated figures is typically used in cane shredding process, where the cane or sugar cane (not shown) is crushed by the hammer (100) against an anvil plate (not shown) of the shredder or shredder device (not shown). However, the hammer (100) may also find its usage in similar applications where shredding of raw material for extraction of juice may be required. The shredder device may include multiple hammers (100) rotatably coupled to rotors and arranged between the anvil plates. The anvil plates are generally fixed and the hammers (100) are rotated against the cane feed for cutting the cane to smaller parts. The hammers (100) are fixed to a rotor shaft for rotating against the cane so that the cane feed is cut into smaller parts or pieces. In one embodiment, a plurality of self-sharpening shredder hammer (100) is provided in a shredder for shredding cane or sugar cane.

The description hereinafter will be described with reference to a single hammer of the cane shredder device. However, it is to be understood that the description for the other hammers in the cane shredder device will also be the same. The cane shredder device / shredder generally consists of more than one hammers and the hammers are of same design and features. Therefore, the explanation for a single hammer will be applicable for the remaining hammers as well and it should not be meant to limit the scope of the invention.

In the illustrated FIGS. 3 and 4, the hammer (100) includes a hammer body (102) having a first end (104). The first end (104) of the hammer (100) includes a shank portion (106) and an eye region (108). The eye region (108) of the hammer body (102) is pivotally connected to a shaft of a rotor or a motor such that an axis of the rotor and an axis of the eye region (108) are aligned with each other. The hammer body (102) further includes a plurality of faces (110) which extends from the shank portion (106) towards a second end (112) of the hammer body (102).

The second end (112) of the hammer body (102) is provided with a flange (124). The flange (124) is provided with a plurality of grooves (07). The plurality of grooves (07) is laterally extending on a first face (116) and a third face (118) of the hammer body (102). In the illustrated embodiment, the first face (116) includes one groove and the third face (118) includes one groove. Thus, the second end (112) of the hammer body (102) include two grooves. In other words, the grooves (07) are provided on two of opposing faces (116, 118) of the plurality of faces (110) not provided by the plurality of holes (114). The grooves (07) in the first and third faces (116, 118) are in a square or rectangular shaped. However, it should be understood that the groove may be in other shapes like V-groove or any shape to serve the purpose of accommodating a plurality of strips which form a tip of the hammer (100).

In the illustrated embodiment of FIGS. 3 and 4, the plurality of strips includes a first set of strips (03) and a second set of strips (04). Each strip of the first set of strips (03) and the second set of strips (04) include a central plate (03-A, 04-A) and a pair of arms (03-B, 04-B) extending from the central plate (03-A, 04-A). Thus the shape of each strip of the first set of strips (03) and the second set of strips (04) will resemble an alphabet “C” or a square bracket. In other words, the first set of strips (03) and the second set of strips (04) are having a C shaped body, having the central plate (03 -A, 04- A) and the pair of arms (03 -B, 04-B) extending from ends of the central plate (03-A, 04-A). In the illustrated FIG. 4, the pair of arms (03-B, 04-B) extend from ends of the central plate (03-A, 04-A) and will bend forward in order to form a claw for accommodating into the grooves (07) at the first face (116) and the third face (118). That is to say, the arms (03-B, 04-B) of the first set of strips (03) and the second set of strips (04) are adapted to be seated in the grooves (07).

In the illustrated embodiments shown in FIGS. 3-6, the first set of strips (03) are made of hard material having hardness ranging 50 - 65 HRC or more. Thus, the first set of strips (03) in the hammer (100) are hard strips or hardened strips. Also, the second set of strips (04) are made of softer material having hardness ranging 18 - 40 HRC. Thus, the second set of strips (04) in the hammer (100) are soft strips. The terms “first set of strips”, “hard strips” and “hardened strips” are interchangeably used in the present disclosure. The terms “first set of strips”, “hard strips” and “hardened strips” are relating to same strips which are made of material having more hardness, for example, the hardness of the hardened strips may range from about 50 HRC to about 65 HRC or higher. Similarly, the terms “second set of strips” and “soft strips” are relating to same strips made of material having lesser hardness when compared with the hard strips. The soft strips may have a hardness ranging from about 18 HRC to about 40 HRC. In an embodiment, the second set of strips (04) are having 40 - 70 % lesser hardness than hardness of the first set of strips (03).

In an embodiment, the first and second strips (03, 04) can have thickness (Tl, T2) which are same. In an exemplary embodiment, the second set of strips (04) is having 25 to 75 % smaller thickness (T2) when compared with a thickness (Tl) of the first set of strips (03). In another exemplary embodiment, the second set of strips (04) can have a width (W2) of 1 - 2 mm lesser when compared with a width (Wl) of the first set of strips (03). Referring to FIGS. 5A to 5C, the first set of strips (03) are disposed onto the grooves (07) provided on the flange (124) at the second end (112) of the hammer body (102) (enlarged view is shown in FIG. 7A). Further, the second set of strips (04) are also disposed onto the grooves (07) not provided with the first set of strips (03). In the illustrated embodiment, one strip of the second set of strips (04) is disposed alternatively between the two strips of the first set of strips (03). That is to say, the hard strip (03) and the soft strip (04) are disposed alternatively, wherein the first set of strips (03) is disposed onto the grooves (07) provided on the flange (124) at the second end (112) of the hammer body (102) such that at least one strip of the second set of strips (04) is present in between the two strips of the first set of strips (03). In another embodiment, two soft strips (04) may be placed between two hard strips (03). That is to say, two soft strips (04) combined each other will be placed alternatively between the two hardened strips (03). In yet another embodiment, three soft strips (04) may be placed between two hard strips (03). That is to say, three soft strips (04) combined each other will be placed alternatively between the two hardened strips (03). Thus any such combination and number of strips which is possible between the hard and soft strips (03, 04) can be obtained to form hammer tips at the second end (112) of the hammer body (102). The combination of alternate soft and hardened strips (04, 03) as illustrated in the figures of the present disclosure is not meant to be limiting the scope of the present invention. In the embodiment shown in FIG. 3 to FIG. 7A, the flange present at the second end (112) of the hammer body (102) includes a straight flange (124). That is to say, a thickness of flange is same as that of the thickness of the hammer body (102). In another alternate embodiment, the number of hardened and soft strips (03, 04) can be varied as per different type of cane and/or product requirement. In yet another alternate embodiment, the flange is a widened flange (128) welded to the hammer body (102) (shown in FIG. 7C) or a widened flange (126) integral to the hammer body (102) (shown in FIG. 7B) at the second end (112), to enable accommodation of more number of the first and second set of strips (03, 04), when compared with the embodiment of the flange (124) shown in FIGS. 3-7A. In the illustrated embodiment shown in FIGS. 3-6, a retainer plate (05) is disposed on an exterior portion of either side of an assembly of the first set of strips (03) and the second set of strips (04) for holding them together and intact at the second end (112) of the hammer body (102). The retainer plate (05) is connected with the hammer body (102) through a plurality of holes (114) provided on two of remaining opposing faces (120, 122) not provided with grooves (07) using a plurality of fasteners like screws (06) for holding the first set of strips (03) and the second set of strips (04) together. That is to say, the plurality of holes (114) are provided on a second face (120) and a fourth face (122) of the plurality of faces (110) of the hammer body (102) using a plurality of fasteners like screws (06) for holding the first set of strips (03) and the second set of strips (04) together.

In another alternate embodiment, the first set of strips (03) and the second set of strips (04) are clamped together by the retainer plate (05) and bolts/screws (06) or can be pasted together with each other through any one of fabrication method of brazing or electro -fusion or a chemical solution (known in the art).

During working, a high relative velocity between the hammer tip having the combination of hardened strips (03) and soft strips (04) and its mating part cause high abrasion of the tip having both the soft strips (04) and the hardened strips (03). The soft strips (04) gets worn out at a faster rate than the hardened strips (03), exposing fresh edges of the hardened strips (03) to the working front. The fresh edges are itself of very fine thickness, behave as fresh edges, leaving behind always sharpened edges. In other words, the second set of strips (04) is adapted to wear at a faster rate than the first set of strips (03) since the second set of strips (04) are made of soft material and the first set of strips (03) are made of hard material, thereby exposing fresh edges of the first set of strips (03) for shredding to achieve the object of self-sharpening feature in the hammer. In an embodiment, for example for a new hammer tip, the soft strips (04) are kept smaller in dimension than hard strips (03), so that the hard strips (03) are always available for action from a new tip. That is to say, the second set of strips (04) is having 25 to 75 % smaller thickness when compared with thickness of the first set of strips (03).

Comparison of conventional hammer tip and hammer tip of the present invention is provided as below:

Advantages

In an embodiment, self- sharpening feature is always present as the sharpened edges for working against blunt edges in existing tips.

In an embodiment, uniform performance of the equipment is achieved and it is independent of the wear rate.

In an embodiment, uniform quality of the output product is achieved and it is independent of the wear rate.

In an embodiment, uniform consumption of power is observed and it is independent of wear rate. In an embodiment, ease of assembly during manufacturing and replacement are obtained and there is no need to do a step, followed by making a hole by counter boring on the hammer to locate the tip. Only straight grooves are required which are comparatively easy to machine as compared with round counter hole.

Industrial applicability

Present invention of self-sharpening hammer tip finds its potential application in sugar cane industry, where the cane or sugarcane raw material is required to be cut or shredded into smaller part for efficient extraction of juice. However, the disclosed self-sharpening hammer tip for the shredder device may also find its application in other shredders which may be used for shredding and juice extraction.

List of reference numerals and reference characters / signs

01 : Hardened single piece construction of hammer of prior art

02: Soft material of hammer of prior art

03: Hardened Strips or first set of strips of hammer of the present invention

03-A: Central plate of the first set of strips 03-B: Pair of arms of the first set of strips

04: Soft Strip or second set of strips of hammer of the present invention

04-A: Central plate of the second set of strips

04-B: Pair of arms of second set of strips

05 : Retainer Plate of hammer of present invention

06: Screws

07 : Plurality of grooves

100’: Hammer of prior art

100: Self-sharpening hammer of present invention

102: Hammer body

104: First end of the hammer body

106: Shank portion

108: Eye region

110: Plurality of faces 112: Second end

114: Plurality of holes

116: First face

118: Third face

120: Second face

122: Fourth face

124, 126, 128: Flange

Tl: Thickness of first set of strips

T2: Thickness of second set of strips

W 1 : Width of first set of strips

W2: Width of second set of strips