Title of Invention

"A CANTILEVER SHELF DEVICE FOR A REFRIGERATOR"

Abstract

A cantilever shelf device for a refrigerator having a pair of guide rail with groove with a self retainer mounted in the each groove which can be slided at any night in the refrigerator, a self stopper fixed with in each support angle in a pair of support angle, the two flat surfaces on the opposite side of the shelf retainer and said surface configured to butt against corresponding front and rear of the groove in case shelf is parallel to ground, the surfaces are located away form corresponding internal groove when fitted up and shelf retainers with surface texture provide a high coefficient of friction.

Full Text

The present invention relates to a cantilever shelf device for a refrigerator. More specifically, the subject invention relates to vertically adjustable cantilever shelf which is movable inside the refrigerator without unloading and dismantling of shelf from the track at any height in the refrigerator. BACKGROTIND OF INVENTION A typical refrigerator is provided with a number of shelves for storing food items and containers in the refrigerator. Generally shelves are cantilevered from tracks mounted at the rear of the compartment so that they can be moved between fixed number of predetermined positions.along the tracks. The spacing above each shelf must be sufficient to allow items of various sizes to be placed thereon without interference. Occasionally therefore the shelves must be repositioned to a different height when the shelves are cantilevered from track all the items must be removed from the shelf before the shelf can be removed from me track and remounted at a new position. Also the shelf can be located only at the predetermined positions. The prior art is full of vertically adjustable cabinet shelves such as those found in the food storage compartment of house hold refrigerator. One such example is found in U.S. Patent No. 2,841,459. U.S. 3,982,801 describes a power-operated vertically adjustable shelf which is supported by shelf arms in cantilevered fashion at the rear of an appliance cabinet by a gear and roller on each shelf arm, with each gear and roller vertically offset engaging a vertically extending toothed rack and a roller track. Electric drive means, carried by the cabinet, powers a vertically extending drive shaft of which the torque is transmitted to the shelf operating gear through a normally disengaged clutch which is engaged by user operating means adjacent to the front of each shelf whereby powered vertical movement of the shelves is achieved. A dual position selector shelf switch is operable upon opening the door to permit the user to select up or down power shelf movement with the shelf switch being neutralized upon closing of the cabinet door. U.S. 5913584 describes a vertically adjustable shelf for a refrigerator which includes a mounting assembly which cooperates with a pair of vertically extending tracks to position the adjustable shelf at a plurality of predetermined positions, a support assembly is carried by the mounting assembly and movable relative to the mounting assembly so that the support assembly can be positioned at each position between the plurality of predetermined positions, and an encapsulated shelf carried by the support assembly. The mounting assembly has a pair of vertical rack gears and a pair of track mounting brackets which engage the tracks. The support assembly includes a knob centrally located at a forward end of the shelf and a gear box connecting the knob with the rack gears so that the support assembly moves relative to the mounting assembly when the knob is turned. In some of the existing arrangements, the shelf is hooked on the guide rail or the track restricting the adjustment of the shelf by the pitch of the slot consequently. Adjustment of height of the shelf requires complete dismantling of shelf from the guide rail. This causes inconvenience to the user and is not a user friendly arrangement. Therefore there always existed a need to have a relatively simpler adjustment arrangement which is quick and easy to operate, cost effective, durable, infinitely adjustable and can be easily used in the existing refrigerators. SUMMARY OF INVENTION The object of the present invention is to provide cantilever shelf which is simpler to use and easily accessible by the user. Other object of the present invention is to provide a self adjustable pitch free cantilever shelf which can be freely moved to any height. Another object of the present invention is to provide an adjustable cantilever shelf which can be adjusted without dismantling. Yet another object of the present invention is to provide a cantilever shelf which is held by friction at its location. Yet another object of the present invention is provide a cantilever shelf which avoids cleaning of the notches or the grooves in the body of the refrigerator a source of unwanted material. The present invention is directed to adjustable shelf for refrigerator cabinet or the like wherein each shelf is supported in a cantilever manner to provide for quick and easy adjustment by the user both upwardly and downwardly from one horizontal planes to another with the refrigerator food storage compartment. The present invention describes a mounting assembly consisting of a pair of vertically extending tracks to position the adjustable shelf, a support assembly carried by the mounting assembly and movable relative to the mounting assembly so that the support assembly can be positioned at any position in the track and an encapsulated shelf carried by the support assembly. The mounting assembly has a pair of vertical mounting brackets which are called the guide rails. The support assembly includes a pair of support arms attached to the shelf at the perforations provided at fixed intervals along its length. A least one of the support arms have a hooked end which gets engaged in the recess of the shelf retainer so that the support assembly moves relative to the mounting assembly when the shelf is tilted. A shelf retainer is specially designed to provide good friction against the walls of the tracks and has a typical shape and configuration to stop the tilting of the shelf after a particular angle. The shelf is moved from one position to the other by tilting it to a small angle without unloading. According to the present invention, there is provided a cantilever shelf device for a refrigerator comprising a pair of vertical guide rails (1) each having an internal groove along its length, a shelf retainer (7) slidably mounted within each groove, each shelf stopper integral with a support angle (2), a shelf (3) being fixed with a pair of said support angles wherein the two fiat surfaces (8) on the opposite sides of the shelf retainer, said surface (8) configured to butt against the front surface of the internal groove and the other configured to butt against the rear surface of the internal groove when the shelf is in horizontal position, said surfaces (8) being located away from corresponding surfaces of the internal groove when the shelf is titled in anti-clockwise direction and wherein the said surfaces of shelf retainer and the corresponding surfaces of internal groove facing said surfaces (8) of shelf retainers are provided with surface texture having a high coefficient of friction. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Fig. 1 depicts the existing arrangement of the shelf on the guide rail. Fig. 1 (a) depicts the existing arrangement of the shelf on the guide rail. Fig. 2 depicts a fragmentary view of the refrigerator showing shelf adjusting arrangement. Fig. 3 depicts the design of new guide rail. Fig. 4 depicts the design of support arm. Fig. 5 (a) depicts the design of right arm of the shelf retainer Fig. 5(b) is the side view of the self retainer showing the left arm. Fig. 6 depicts the schematic diagram of normal position of shelf Fig. 6 (a) depicts the load distribution when the shelf is in normal position Fig. 7 depicts the schematic diagram of tilted position of shelf Fig. 7 (a) depicts the load distribution when the shelf is in tilted position Fig. 8 depicts the schematic diagram of fail safe of shelf A household refrigerator mainly comprises of a metal shell, an inner liner generally molded with plastic with a suitable insulating material. The wall structure forms top, bottom, upright back and side walls of the food storage compartment. This food storage compartment is cooled by evaporator of the refrigerating system. The food storage compartment has a front access opening which is normally closed by hingedly connected door of the refrigerator. The refrigerator generally have a plurality of shelves which may be metallic or non metallic preferably made of plastics. The shelves are spaced apart at different positions. Below these shelves there is a storage bin for storing food items. Fig. 1 shows the existing arrangement of the shelf in the refrigerator. The shelf is supported by a pair of support arms (2) which have a hooked ends (5). The hooked end (5) of the support arm (2) gets hooked into the guide rail (1). Thus the vertical adjustment of the shelf (3) is restricted by the pitch of slots on guide rail (1). As shown in Fig. 2 the present invention conceives a mounting assembly consisting of a pair of vertically extending tracks to position the adjustable shelf, a support assembly carried by the mounting assembly and movable relative to the mounting assembly so that the support assembly can be positioned at any position in the track and an encapsulated shelf carried by the support assembly. The mounting assembly has a pair of vertical mounting brackets which are called the guide rails (1). The support assembly includes a pair of support arms (2) attached to the shelf (3) at the perforations (4) provided at fixed intervals along its length. At least one of the support arm (2) has a hooked end (5) which gets engaged in the recess (6) of the shelf retainer (7) so that the support assembly moves relative to the mounting assembly when the shelf (3) is tilted. Fig. 3 shows the structure of the new track or the guide rail (1). The guide rail has 'C' cross section and provides the guide as well as a surface for friction. The guide rail (1) is made of CRCA powder coated steel and is closed on three sides. This is mounted on the side walls of the refrigerator. Fig. 4 shows a single support arms having perforations (4) or holes at small intervals all through its length. The rear end of the arm has a hook (5) which is to be engaged with the shelf retainer (7). Fig. 5 (b) shows the self retainer (7) comprising of a left arm (9) having projections at the alternate opposite ends one facing the front wall of the track and the other facing the rear side of the track facing the rear portion of the refrigerator. These projections have the flat surfaces (8) which butt against the walls of the track and retain their position there due to the friction. The shelf retainer (7) is made of Aluminium metal and specially designed to provide good friction against the walls of the tracks . As shown in Fig 5 (a) the right arm (10) of the shelf retainer (7) has a typical shape and configuration to stop the tilting of the shelf after a particular angle (not exceeding 2.5° or 15 mm). The right arm (10) of the shelf container (7) has middle end called the pivot point (11) touching the rear wall of the refrigerator and designed to have a inwardly slant towards both ends which is in conformity with the required angle of the shelf while tilting. Fig. 6 and Fig 6(a) shows the load division of the shelf (3) when the shelf retainer (7) is in the normal position. In the normal position the load of the shelf tries to rotate the shelf it w.r.t. pivot point in downward direction. With the result the two surface butts of the left side arm (9) of the shelf retainer (7) butt against the track wall surface. The frictional force created between the two surfaces retain the shelf position and prevents the shelf from falling down. Fig. 7 and Fig. 7(a) shows tilted position of the shelf (3) and load distribution thereon. When the shelf (3) is tilted by the user from the front it rotates the shelf w.r.t. pivot point in upward direction. The tilting angle is kept at 2.5° +2.5° (max.) which equals a lifting by 15mm +15 (max.). The first 15mm (2.5°) lift is for safety because the user can tilt the shelf by small angle to keep large items on the lower shelf. When the shelf (3) is lifted more than 15mm (2.5°) the two surfaces of the projected ends of the left arm (9) of the shelf retainer (7) loose contact from the track surface. As the two surfaces are not in contact, there is no frictional force acting to retain position of the shelf (3) . Thus the shelf (3) can be changed by moving it upwardly or downwardly. Fig. 8 shows the action of the frictional force when the shelf (3) is moved in the upward direction. When the user force is removed then the weight of the shelf (3) and load thereon tries to rotate it w.r.t. pivot point (11) in downward direction. This eventually results in butting the two surfaces of shelf retainer (7) against track surface. The frictional force created between the two surfaces retains the shelf position and prevents the shelf (3) from falling down. The present invention is thus an advantage over the prior art in which the frictional force provides the attributes and the benefits which have not been there earlier. The arrangement of the subject invention can be adopted for glass, wire and plastic shelves in the refrigerator. The cantilever shelf of the invention is easy to manufacture and durable under the arduous and repetitive use. The subject invention is a mere statement of invention and should not be construed to restrict the broad scope of the invention in any manner. WE CLAIM: 1. A cantilever shelf device for a refrigerator comprising a pair of vertical guide rails (1) each having an internal groove along its length, a shelf retainer (7) slidably mounted within each groove, each shelf stopper integral with a support angle (2), a shelf (3) being fixed with a pair of said support angles wherein the two flat surfaces (8) on the opposite sides of the shelf retainer, said surface (8) configured to butt against the front surface of the internal groove and the other configured to butt against the rear surface of the internal groove when the shelf is in horizontal position, said surfaces (8) being located away from corresponding surfaces of the internal groove when the shelf is titled in anti-clockwise direction and wherein the said surfaces of shelf retainer and the corresponding surfaces of internal groove facing said surfaces (8) of shelf retainers are provided with surface texture having a high coefficient of friction. 2. A cantilever shelf device as claimed in claim 1, wherein said support angle is provided with a hooked end (5) to engage into recess (6) of said shelf retainer. 3. A cantilever shelf device as claimed in claim 2, wherein the support angle has a plurality of perforations (4) provided at fixed intervals along its length. 4. A cantilever shelf device as claimed in claim 1, wherein said shelf retainer is made of alluminium. 5. A cantilever shelf device as claimed in claim 4, wherein said shelf retainer has a pivot (11), surfaces (10) of said retainer tapering on each side of said pivot. 6. A cantilever shelf device as claimed in claim 5, wherein said surface (10) of shelf retainer is configured to stop tilting of shelf beyond an angle of 2.5 degrees. 7. A cantilever shelf device as claimed in claim 1, wherein said guide rail is made of cold rolled critically annealed (CRCA) powder coated steel. 8. A cantilever shelf device as claimed in claim 7, wherein said guide rail has a 'C cross section. 9. A cantilever shelf device as claimed in claim 8, wherein said guide rail is mounted on the said walls of refrigeration. 10. A cantilever shelf device as claimed in any of the preceding claims, wherein the shelf is fixed to said pair of support arms at the said perforations in the support arms. 11. A cantilever shelf device for a refrigerator, substantially as hereinbefore described with reference to the accompanying drawings.

Documents:

938-DEL-2003-Abstract-(16-12-2008).pdf

938-del-2003-abstract.pdf

938-DEL-2003-Claims-(16-12-2008).pdf

938-del-2003-claims.pdf

938-DEL-2003-Correspondence-Others-(16-12-2008).pdf

938-del-2003-correspondence-others.pdf

938-del-2003-correspondence-po.pdf

938-DEL-2003-Description (Complete)-(16-12-2008).pdf

938-del-2003-description (complete).pdf

938-del-2003-description (provisinal).pdf

938-DEL-2003-Drawings-(16-12-2008).pdf

938-del-2003-drawings.pdf

938-DEL-2003-Form-1-(16-12-2008).pdf

938-del-2003-form-1.pdf

938-del-2003-form-18.pdf

938-DEL-2003-Form-2-(16-12-2008).pdf

938-del-2003-form-2.pdf

938-del-2003-form-26.pdf

938-del-2003-form-3.pdf

938-del-2003-form-4.pdf

938-DEL-2003-Form-5-(16-12-2008).pdf

938-del-2003-form-5.pdf

938-DEL-2003-Petition-137-(16-12-2008).pdf