reference will now be made in detail to presently preferred embodiments of the invention , one or more examples of which are illustrated in the accompanying drawings . each example is provided by way of explanation of the invention , not limitation of the invention . in fact , it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof . for instance , features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment . thus , it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents . referring to fig1 , a funnel 10 is shown having a receiving chamber 12 defined by a generally frustoconical first portion 14 and a generally square second portion 16 in fluid communication with each other . receiving chamber 12 is coupled to a mounting section 40 and contains a valve mechanism 30 . the shape described and shown in the figures facilitates the receipt of a rectangular oil container having a neck and opening formed on one end of the top . thus , the body of the container can be received in square portion 16 while the neck and opening can be received in frustoconical first portion 14 . it should be understood that the overall shape of receiving chamber 12 may take other forms such as conical , square triangular , etc . generally frustoconical first portion 14 is defined by a side wall 18 that intersects with generally square second portion 16 . generally square second portion 16 is defined by a first and second side wall 20 and 22 , respectively , a front wall 24 and a bottom wall 26 ( fig1 and 3 ). a top end of generally frustoconical first portion 14 and generally square second portion 16 terminates at , and is integrally formed with , an inward extending flange 28 that helps to prevent fluid from splashing out or dripping from the top of the funnel . inward extending flange 28 is coupled to one end of valve mechanism 30 , as explained in further detail herein . a bottom portion of generally frustoconical first portion 14 terminates into , and is integrally formed with , a generally cylindrical tube portion 32 that defines a radially extending flange 34 extending therefrom . generally cylindrical tube portion 32 terminates at a bottom edge 36 ( fig2 ), and the tube portion defines an axial bore 38 ( fig3 ) therethrough that is in fluid communication with receiving chamber 12 . referring to fig2 , mounting section 40 is formed from three main parts : a generally cylindrical housing 42 , an internal cylindrical cam 44 and a boot 46 . generally cylindrical housing 42 has a first end 48 that defines a first outward radially extending flange 50 and an opposite second end 52 that defines a second outward radially extending flange 54 . axial slots 56 are formed through generally cylindrical housing 42 and extend axially from first outward radially extending flange 50 through second outward radially extending flange 54 to second end 52 . the axial slots extend along about two - thirds of the length of housing 42 thereby forming multiple flexible housing fingers each defined by a portion of the housing wall located between adjacent slots . axial slots 56 allow the portion of generally cylindrical housing 42 below first outward radially extending flange 50 to expand radially outward between a first position and a larger second position so that the diameter of the axial bore proximate housing end 52 increases from a first diameter to a larger second diameter , as explained in further detail below . generally cylindrical housing 42 also defines an axial bore 58 therethrough that extends from first end 50 to second end 52 . referring to fig2 a , axial bore 58 has three general recessed areas 60 each formed in a housing finger and defined by a radius r that starts at a fixed length and increases as the radius is rotated about one - hundred and twenty degrees , at which point the radius starts back at the fixed length to form the next recess . teeth 62 , formed on an inner circumference of housing 42 about recesses 60 , extend the length of axial bore 58 . the teeth are ramped counter clockwise to allow opposing teeth formed on internal cylindrical cam 44 to ratchet over teeth 58 in one direction but not in the opposite direction . referring to fig2 and 2 b , internal cylindrical cam 44 defines a first end 64 having an outward extending flange 66 and two radially extending fingers 67 thereon , and an opposite second end 68 defining three lobes 70 ( fig2 b ) having teeth 72 formed thereon . lobes 70 act as cam surfaces for engaging the housing fingers as described herein . referring to fig4 , internal cylindrical cam 44 has an axial bore 74 formed therethrough , and a frustoconical wall 76 extends from a surface 75 , defining axial bore 74 , radially inward and terminates in a cylindrical opening 78 . a trapezoidal shaped opening 80 is formed through a surface of frustoconical wall 76 so that the portion of axial bore 74 above frustoconical wall 76 and the portion of axial bore 74 below frustoconical wall 76 are in fluid communication with each other . frustoconical wall 76 cooperates with valve mechanism 30 to prevent fluid from flowing through funnel 10 , as further described herein . referring again to fig2 , boot 46 has a generally cylindrical main portion 82 having a first end 84 and an opposite second end 86 . an outwardly extending flange portion 88 is located intermediate first and second ends 84 and 86 . boot 46 may be formed from any pliable material such as polymers and elastomers , and in one preferred embodiment boot 46 is formed from an elastomer material . the walls of boot 46 are thin and generally conform to the outer surface 89 of generally cylindrical housing 42 . referring to fig2 and 4 , valve mechanism 30 is formed from an elongated shaft 90 having a disk 92 coupled at a first end 94 and a frustoconical valve portion 96 formed at a second end 98 . frustoconical valve portion 96 contains a trapezoidal opening 100 . a stem 102 is formed at second end 98 and includes a recessed groove 104 . it should be understood that the valve opening can take on any shape so long as it corresponds to the shape of the opening formed in the internal cylindrical cam . referring to fig3 and 3 a , funnel 10 is assembled as follows . boot 46 may be formed separate from generally cylindrical housing 42 or molded around the housing . if formed separate , housing 42 is inserted into boot 46 by stretching the boot over the housing body . internal cylindrical cam first end 64 is placed into housing bore 58 through housing second end 52 so that lobes 70 are received in recesses 60 , and end 52 of generally cylindrical housing 42 abuts intermittent radially outward extending flanges 110 ( fig2 ). flanges 110 prevent housing 42 from axially sliding off internal cylindrical cam 44 . in this configuration , internal cylindrical cam teeth 72 interengage with housing teeth 62 . because of the shape of the teeth , housing 42 may only be rotated in the clockwise direction with respect to the view shown in fig3 looking into receiving chamber 12 . it should be understood that while housing 42 is prevented from sliding off internal cylindrical cam end 68 in one direction , and may only rotated with respect to the internal cam in the clockwise direction , it may slide axially in the opposite direction over a limited distance , as discussed further below . once housing 42 and boot 46 are installed on internal cylindrical cam 44 , internal cylindrical cam first end 64 is placed into cylindrical tube portion bore 38 so that internal cylindrical cam fingers 67 are received in corresponding recesses 69 ( fig2 ) and flange 66 is received in a corresponding annular groove 65 ( fig2 ). the engagement of flange 69 and annular groove 65 axially locks internal cylindrical cam 44 with respect to generally cylindrical tube portion 32 , and fingers 67 and recesses 69 rotationally lock the two parts together . a spring 47 is inserted intermediate cylindrical tube portion flange 34 and housing flange 50 . when cam 44 and housing 42 are installed in cylindrical tube portion 32 , an axial space 71 ( fig1 ) is provided between housing first end 48 and cylindrical tube portion end 36 to allow the housing to move axially with respect to internal cylindrical cam 44 over a limited distance defined by axial space 71 . spring 47 biases the housing axially away from cylindrical tube portion flange 34 . referring to fig3 and 3 a , valve mechanism 30 is next inserted into receiving chamber 12 such that shaft first end 94 is received in a groove 106 ( fig2 ) formed by two adjacent flanges 108 . opposite shaft end 98 is received in internal cylindrical cam bore 74 ( fig3 a ) so that valve mechanism frustoconical valve portion 96 is adjacent to internal cylindrical cam frustoconical wall 76 . valve mechanism 30 is secured in place by pushing shaft stem 102 through internal cylindrical cam opening 78 ( fig4 ) so that recessed groove 104 receives the walls defining opening 78 . once valve mechanism 30 is in place , disk 92 may rotate relative to funnel receiving chamber 12 so that valve opening 100 may align with internal cylindrical cam opening 80 ( fig4 ). thus , by rotating disk 92 by at least forty - five degrees , opening 80 will move out of alignment with opening 100 thereby preventing fluid flow through the funnel . thus , valve mechanism 30 provides the user with the ability to allow or stop fluid from flowing through funnel 10 depending on the position of valve member 30 . referring to fig5 , a portion of an internal combustion engine 112 is shown having a distributor cap 114 , a belt pulley 116 and valve covers 118 and 120 into which funnel 10 is received . valve cover 120 has an oil inlet 122 that defines a circular opening 123 ( shown in phantom in fig6 a - 6c ) for the addition of oil into the engine . referring to fig6 a , in use funnel 10 is positioned so that mounting section 40 is within inlet opening 123 with housing flange 88 abutting the top of inlet 122 . inlet opening 123 and the inside of valve cover 120 are shown in phantom . looking into housing end 86 , lobes 70 align with recess 60 so that the diameter of housing 42 is generally constant along the axial length of housing 42 . once the funnel is properly positioned , the user rotates generally cylindrical tube portion 32 and receiving chamber 12 counterclockwise with respect to generally cylindrical housing 42 so that internal cylindrical cam teeth 72 ride over housing teeth 62 . the relative rotation causes the lobes to bias the recess walls radially outward and into engagement with the wall of opening 123 . it should be understood that the user can rotate housing 42 relative to internal cylindrical cam 44 in one of two ways . first , the user can hold housing 42 stationary by gripping flange 50 and rotate internal cylindrical cam 44 with respect to the housing by turning receiving chamber 12 . alternatively , the user may hold internal cylindrical cam 44 stationary through receiving chamber 12 and rotate housing 42 relative to the cam . in either case , the housing teeth ride over the cam teeth so that the radially larger parts of the lobes engage the radially smaller parts of the recess causing the diameter of housing end 52 to increase ( fig6 b ). as a result , the outer surface of boot end 86 engages the inner circumference of oil inlet circular opening 123 causing a tight seal to form . the radius of housing end 52 may increase by 0 . 45 inches and can fit into openings ranging from 1 . 15 inches ( 31 mm ) to 1 . 60 inches ( 43 mm ) in diameter . once the oil funnel is engaged with the opening , disk 92 may be rotated so that valve mechanism opening 100 aligns with internal cam opening 80 . in this configuration , the user can pour fluid into funnel 10 ( fig5 ) to fill the fluid reservoir . once the user finished filling the reservoir , disk 92 is rotated by at least forty - five degrees so that opening 100 moves out of alignment with opening 80 . this prevents fluid from passing though the funnel and spilling from mounting end 40 onto the automobile engine or exterior finish . referring to fig6 c , the funnel may be released from inlet opening 123 by axially moving internal cylindrical cam 44 relative to housing 42 . in particular , the user may press down on receiving chamber 12 causing internal cylindrical cam end 68 to push through housing end 52 . in particular , as the housing moves relative to the internal cylindrical cam , housing flange 50 moves toward flange portion 34 against the bias of spring 47 . thus , as the cam is pushed through the housing , cam teeth 72 disengage from housing teeth 62 ( fig6 c ) allowing housing end 86 to decrease in radial diameter thereby releasing the funnel from the inlet . after the funnel is released and removed from the inlet , the user can realign lobes 70 with recesses 60 by move rotating housing 42 with respect to internal cylindrical cam 44 until the lobes align with the recesses . once aligned , housing 42 may be moved axially along internal cylindrical cam 44 until intermittent flanges 110 abut with housing end 86 .