referring now to the drawings wherein like reference characters designate like or corresponding parts throughout several views , there is shown in fig1 a - 1e , a shelf support generally designated 10 according to one embodiment of the present invention . drawing attention first to fig1 a and 1b , the shelf support can be seen to have a substantially cylindrical shape and comprises a cylindrically - shaped rod portion 12 having a smooth outer surface and a central axis x , and a seating portion 14 extending from the rod portion 12 . optionally , the rod portion 12 and the seating portion 14 are integrally formed with each other and are made of a plastic material , which is of sufficient strength to support a standard shelf 16 ( fig1 c - 1e ), when the shelf support 10 is mounted to a side - wall 18 ( best seen in fig1 c ). the seating portion 14 comprises a spiral - shaped outer surface 20 . each point of the outer surface 20 along the spiraling portion thereof is disposed at a different distance from the central axis x . to elaborate , example points of the outer surface designated a , b and c are shown to constitute potential support surfaces of the shelf support , wherein diameter d 1 & lt ; d 2 & lt ; d 3 . it should be noted , however , that the outer surface 20 , further comprises a radially oriented straight portion 21 ( seen in fig1 a , 1 d and 1 e ), which connects the support surface having the largest diameter to the support surface having the smallest diameter . for ease of rotation , the seating portion is optionally formed with a recess 22 , which , in this example , is shaped to allow insertion of a screw driver with a slotted tip ( not shown ). turning attention to fig1 c and 1d , the shelf support 10 is shown to be rotatably mounted via the rod portion 12 thereof to a horizontal bore 24 ( fig1 c ) formed within the wall 18 . the seating portion 14 is disposed underneath a lower portion 26 of a shelf 16 which is supported in this position by other shelf supports ( not shown ). notably , the shelf is level due to the presence of other shelf supports ( not shown ) but is unstable due to there being a gap or distance ( designated as e ) between the shelf and support surface a , which is the closest support surface to the lower portion 26 of the shelf 16 . notably , distance e corresponds in magnitude to the difference of magnitude between diameters d 1 and d 2 , the importance of which will become clear hereinafter . in operation , to stabilize the shelf 16 , such that it is seated on the shelf support 10 , a user inserts a screw driver tip ( not shown ) into the recess 22 and rotates the shelf support thereby in the direction of arrow 28 ( fig1 d ) about the central axis x until the orientation of the shelf support is that shown in fig1 e , at which point the lower portion 26 of the shelf 16 securely rests on support surface b . drawing attention now to fig1 f , the shelf support 10 is shown disposed underneath a lower portion . 26 of a shelf 16 which is supported in this position by other shelf supports ( not shown ). in contrast to fig1 c and 1d the shelf 16 shown in fig1 f is not level and is resting on the shelf support 10 . to aid visualization only , a horizontal axis designated h and a vertical axis designated v are shown . the operational steps to level the shelf 16 are similar to those described above , with the shelf support 10 being rotated about 250 degrees in a clockwise direction . during rotation the shelf support 10 continuously contacts and pushes the shelf 16 until the shelf is acceptably leveled , for example until it is parallel with horizontal axis h , in a manner similar to that shown in fig1 e . it should be noted that the above described scenarios are examples only and , for example , a shelf support may be at any orientation with respect to a shelf thereabove and may be rotated any appropriate amount , and to any point on the outer surface 20 to bring the shelf to a desired inclination . turning to fig2 a - 2d , examples of shelf supports having anti - rotation elements , for ensuring the prevention of undesired reverse rotation of a shelf support , are shown . in fig2 a a shelf support designated as 30 comprises an anti - rotation element in the form of unidirectional teeth 32 formed on an outer surface of the shelf support 30 . the teeth 32 act to prevent the shelf support , when in contact with a lower portion of a shelf ( not shown ), from rotating in the direction opposite to arrow 28 . similarly , fig2 b shows a shelf support designated as 34 comprising an anti - rotation element in the form of bulges 36 . fig2 c and 2d show a shelf support designated as 42 comprising an anti - rotation element in the form of an axial projection member 44 , optionally made of a rubber material , extending from the seating portion 14 and parallel with respect to the rod portion 12 . in operation , to stabilize a shelf ( not shown ) disposed above the shelf support 42 , a user rotates the shelf support to an orientation where it engages the shelf , while the rod portion 12 of the shelf support 42 is not fully inserted into the bore 24 , as seen in fig2 c . when the desired orientation is reached , the user fully pushes the shelf support 42 towards the wall 18 , as shown in fig2 d , wherein further rotation of the shelf support 42 is arrested by the frictional contact of the axial projection member 44 with the wall 18 . as should be understood , there may be a plurality of axial projection members , which may have any desired shape and may be made of any material which can produce the desired frictional effect . alternatively the axial projection member 44 may be made of a hard material , for example , steel and may be sharp enough to be inserted into a portion of a wall to which such shelf support is mounted , thereby preventing further rotation of the shelf support . it should be noted that in all cases a shelf support of the present invention is able to be freely rotatable in at least one direction whilst at least partially mounted to a bore formed within a wall . referring to fig3 a - 3e , other modifications of a shelf support in accordance with the present invention are shown . fig3 a illustrates a shelf support 46 with a hollow seating portion , wherein the spiral - shaped outer surface 48 is supported to the rod portion 12 via radial support spokes 50 engaging both . fig3 b illustrates a shelf support 52 comprising a circular shaped seating portion 14 and an off centre rod portion 12 , i . e . a rod portion that is not aligned with the central axis x . fig3 c illustrates various schematic front views of example alternate shapes for the seating portion of the shelf support in fig3 b . notably the shape may be any symmetrical shape or perfected polygon . fig3 d illustrates a shelf support 54 similar to that shown in fig1 a - 1e , comprising an outer surface with a non - spiral shaped curved portion 56 instead the straight portion 21 of shelf support 10 . it should be understood that , due to manufacturing realities , small percentages of an outer surface of a shelf support such as the curved portion 56 and the straight portion 21 may have a non - spiral - shape , while not departing from the spirit of the invention . fig3 e illustrates a shelf support designated as 38 comprising shavings to form discrete flat support surfaces 40 , to extend substantially flush under the supported surface of a shelf . notably the shavings 40 function in a slightly different manner to the unidirectional teeth 32 and bulges 36 shown in fig2 a and 2b , respectively , in that the shavings provide a flat surface for a shelf to rest on thereby removing any incline for a shelf to slip on . therefore , for slippage to occur a shelf resting on shelf rest 38 would need to overcome an edge or apex 41 by first distancing itself from the shelf rest 38 . turning attention to fig4 a and 4b , there is illustrated a shelf support , generally designated as 60 . the shelf support 60 comprises a cylindrically - shaped rod portion 12 with a smooth outer surface and a seating portion 62 extending therefrom . the seating portion 62 comprises a cylindrical section 64 , and an axially - projecting lip 66 disposed between the cylindrical section 64 and the rod portion 12 . the lip 66 is of a roughly helical - shape lip and comprises a front axial surface 68 , a rear axial surface 70 , a side surface 72 , a first end 74 ( best seen in fig4 a ) and a second end 76 which extends from the first end 72 around approximately three quarters or 270 degrees of the cylindrical section 64 , along which it axially projects in a gradually growing pattern in a direction away from the rod portion 12 . the axial projection of the lip at the second end 76 has a magnitude denoted by the letter f ( fig4 d ), the significance of which will become clear hereinafter . one use of the shelf support 60 will now be described with reference to fig4 c and 4d . in fig4 c the rod portion 12 of shelf support 60 is mounted to a horizontal bore 24 formed within a first side - wall 80 of a cabinet ( partially seen ). mounted on the cylindrical section 64 of the shelf support 60 is a portion of a shelf 82 . as can be understood , other portions of the shelf 82 may be supported by additional shelf supports ( not shown ). notably a first side - face 84 of the shelf 82 is adjacent the first side - wall 80 of the cabinet with the first end 74 of the lip 66 wedged there between , and a second side - face 86 of the shelf 82 is adjacent a second side - wall 88 of the cabinet , spaced therefrom by a distance of magnitude f . turning attention to fig4 d , after a user rotates the shelf support 60 counterclockwise by about 270 degrees , the portion of the lip 66 wedged between the first side - face 84 of the shelf 82 and the first side - wall 80 grows , pushing the shelf 82 towards the second side - wall 88 , closing the gap therebetween and thus securing the position of the shelf 82 . a further result of the pushing motion is that the shelf support itself is thrust towards the adjacent wall to which it is mounted . thus the axially - projecting lip also functions as an anti - slip element , preventing the shelf support from being rotated in an undesired direction by moment applied thereon from the adjacent shelf . therefore there is no need for an anti - slip element , or any securing or locking element . notably all components of a shelf support of this kind do not protrude and are not visible on the other side of a wall to which the shelf support is mounted . it should be noted that the axially projecting surface described above may follow any acceptable growth pattern , so as to accomplish the above described function . for example , such shape may also be comprised by an exponential or step growth , etc . it should also be noted that the first end and second end of such a lip may be disposed at different points and extend along different percentages of a seating portion , and also may axially extend in a clockwise direction , as opposed to the counterclockwise direction of growth shown in fig4 a - 5e , as long as a growth pattern is present to provide the above described gap - closing function . alternatively the axially projection of the lip may have a uniform tapered shape as illustrated in fig4 e by a shelf support , generally designated as 200 . the shelf support 200 comprises a cylindrically - shaped rod portion 12 with a smooth outer surface and a seating portion 202 extending therefrom . the seating portion 202 comprises a cylindrical section 204 , and an axially - projecting lip 206 disposed between the cylindrical section 204 and the rod portion 12 . the cylindrical section is formed with a radial recess 208 which is designed for engagement with a spanner ( not shown ) via which a user may turn the shelf support 200 to a desired orientation . the lip 206 does not follow a growth pattern but has a uniform tapered shape around the diameter of the shelf support 200 . the lip 206 is formed with an aperture 210 designed for insertion of a key ( not shown ) via which a user may turn the shelf support 200 to a desired orientation . notably the sizes and positions of the radial recess 208 and aperture 210 may vary according to design preference . referring now to fig5 a and 5b , a shelf support generally designated 90 is shown . the shelf support 90 is similar to the shelf support 60 except that the seating portion 92 comprises a first portion 93 having a spiral - shaped outer surface 94 with a straight portion 21 , and a second portion constituted by an axially - projecting lip 96 having a first end 98 ( best seen in fig5 a ) and a second end 100 which extends from the first end 98 around approximately half or 180 degrees of the spiral - shaped outer surface 94 . while the shelf support 90 may be used in the manner described above for the previous embodiments , an alternative use will now be described therefor , with reference to fig5 c - 5e which illustrate the assembly of a cabinet ( partially shown ) comprising a back wall 100 , a first side wall 102 disposed perpendicular to and adjacent the back wall 100 , a second side wall disposed opposite to the first side wall ( not shown ) and a shelf 104 . fig5 c shows the shelf 104 partially mounted on a shelf support 10 , with the shelf 104 slanted upward slightly so that a bore 106 , formed with the first side wall 102 , is visible . in fig5 d the shelf support 90 has been mounted to the bore 106 , with the shelf 104 , still slightly non - level , being brought to rest on a portion of the spiral shaped outer surface 94 thereof . notably a small portion of the first end 98 of the axially - projecting lip 96 is disposed between the first side wall 102 and the shelf 104 . in fig5 e the shelf support 90 has been rotated counterclockwise , i . e . in the direction of arrow 108 , until the straight portion 21 of the spiral - shaped outer surface 94 contacts an adjacent side - portion 110 of the shelf 104 . this single rotational movement of the shelf support 90 results in the following : leveling of the shelf 104 , as the shelf now rests on a portion of the spiral - shaped outer surface 94 having a smaller diameter than the portion which it was shown to rest on in fig5 d ; pushing / securing the shelf 104 against the back wall 100 , via the contact of the straight portion 21 ; the combination of the downwards force of the shelf 104 on the outer surface 94 caused by gravity and the contact of the shelf 104 with the straight portion 21 , causes a self - locking motion , wherein the shelf 104 arrests the shelf support 90 from further rotation ; and pushing / securing the shelf 104 away from the first side wall 102 towards the opposing second side wall ( not shown ), via the lip 96 in a manner similar to that described with reference to fig4 b and 4d . those skilled in the art to which this invention pertains will readily appreciate that numerous changes , variations and modifications can be made without departing from the scope of the invention mutatis mutandis .
a shelf support including a rod portion and a seating portion extending therefrom is provided . the rod portion is adapted for fixing to a support wall . the seating portion includes a spiral - shaped outer surface which constitutes a plurality of support surfaces for supporting a bottom portion of a shelf , where , when the rod portion is fixed to the support wall and the bottom portion of the shelf is disposed above the seating portion , rotation of the shelf support causes a portion of the spiral - shaped outer surface to engage the bottom portion of the shelf .