BLADDER AND MOLD LUBRICATION ASSEMBLY FOR TIRE CURING
PRESS
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to tire vulcanizing/curing presses and more particularly relates to a lubrication assembly and method for applying a tire release lubricant around a bladder and a mold before start of curing a green tire.
BACKGROUND OF THE INVENTION
[0002] In the manufacture of tires, typically used for automobiles and trucks, a green tire is placed in an open mold within a conventional tire curing press. The tire is positioned about a deflated inflatable bladder disposed within a mold section of a molding machine. After, the tire mold is closed and sealed; the inflatable bladder is inflated to force the green tire against the heated mold walls whereby the tire is formed with a tread pattern. After some period of time, the tire is cured, the inflatable bladder is deflated, the mold is opened, and the cured tire is ejected from the mold. The inflatable bladder sometimes stuck to the tire after the molding operation is completed and the inflatable bladder is deflated. Then, a machine operator manually separates the inflatable bladder from the interior wall of the tire before the completed tire is ejected and a new green tire inserted. Such an approach results in a costly and time consuming manufacturing process.
[0003] To overcome this problem a machine operator spray a lubricant over the bladder using a spray gun or brush before the green tire is loaded and after cured tire is unloaded from press cavity. During this process the operator may not lubricate the bladder properly leaving some area without applying the lubricant which may result in improper removal of the bladder from the cured tire and reduces the tire quality. Besides this it is a time consuming process as the operator has to perform the lubrication of the bladder after every curing cycles. Furthermore, if the lubricant is

overused it may accumulate inside the mold so that dust or foreign particles cling over the mold, and again the operator has to stop the machine to clean the mold which reduces the production. Also, the operator has to go inside the press to apply the lubricant over the bladder which is a non-safety work as risk of life is involved.
[0004] Majority of prior art approaches use various functional arrangements of components to lubricate the bladder. The problem associated with such prior art approaches is that only the tread area and bottom side wall is effectively coated with lubricant leaving the top side wall while placing the green tire inside the press cavity for curing. In one prior art approach, lubricant spay nozzles are mounted on paddles available in a chuck assembly of a loader device. Such prior art approach consumes large space as it requires larger paddles and it is used only in off the road tire curing presses, since the paddles used in Passenger Car Radial (PCR) /Truck Bus Radial (TBR) tire curing presses is small and also this setup may lead to decrease in strength of the paddles. In addition to this, the TBR/PCR paddles length has to be increased to accommodate this setup and its routing hoses which results in unwanted stroke increase in the press and loading device. Also, the loader paddles on which the nozzle is mounted are moving elements hence the flexible hoses may interfere with the moving elements and the green tire.
[0005] Hence, there is a need for an improved mold and bladder lubrication assembly and method for uniformly applying the lubricant to the mold and the bladder of the tire curing press, as described in greater detail herein.
SUMMARY OF THE INVENTION
[0006] The following summary is provided to facilitate an understanding of some of the innovative features unique to the disclosed embodiments and is not intended to be a full description. A full appreciation of the various aspects of the embodiments disclosed herein can be gained by taking the entire specification, claims, drawings, and abstract as a whole.

[0007] It is, therefore, one aspect of the present invention to provide for a simple, efficient and reliable mold and bladder lubrication assembly and method that is capable of uniformly applying lubricant to a mold and a bladder of a tire curing press.
[0008] It is another aspect of the present invention to provide for an improved method for applying the lubricant uniformly over a desired area.
[0009] It is further aspect of the present invention to provide an improved mold and bladder lubrication assembly and method that is inexpensive, dependable and fully effective in accomplishing its intended purposes.
[0010] In one aspect of the present invention, a mold and bladder lubrication assembly for a tire curing press having a loader and un-loader assembly for loading a green tire into a mold and unloading a cured tire out of the mold via a chuck assembly attached to an arm is disclosed. The assembly includes a mold lubrication nozzle mounted on a gear attached to an inner surface of a stationary circular plate of the loader and un-loader assembly and actuated by an air motor. The mold lubrication nozzle uniformly sprays a mold lubricant to an interior surface of a mold cavity when the loader and un-loader assembly swings inside the mold cavity directly below the mold. The assembly further includes a plurality of bladder lubrication nozzles each mounted on a mounting bracket attached to an outer surface of the stationary circular plate and placed 60° apart from each other. The bladder lubrication nozzles uniformly sprays a bladder lubricant to an outer surface of the bladder when the loader and un-loader assembly enters the mold cavity and moves up and down with the bladder at a slightly inflated condition.
[0011] The chuck assembly swings radially up to a certain angle and slides along a vertical column of the loader and un-loader assembly. The vertical column is composed of a lubricant container connected to the mold lubrication nozzle and the bladder lubrication nozzles for spraying the lubricant on the interior surface of the mold cavity and the outer surface of the bladder. The mold lubrication nozzle with the

gear and the motor arrangement covers the entire or partial area of the mold. The bladder lubrication nozzles apply the bladder lubricant to a top surface of the bladder by totally extending a top ring cylinder of the bladder with the bladder at a slightly inflated condition. The bladder lubrication nozzles apply the bladder lubricant to a bottom surface of the bladder by actuating a lower bead ring cylinder of the bladder so that the bladder with a lower ring moves up. The loader and un-loader assembly and the lower ring cylinder is composed of a linear variable differential transformer to precisely position the loader and un-loader assembly and the lower ring for the lubrication process. The loader and un-loader assembly and position of the lower ring is adjusted to lubricate the entire area of the bladder depending on height of the bladder.
[0012] In another aspect of the present invention, a method for lubricating a tire curing press is disclosed. A loader and un-loader assembly is positioned inside a mold cavity directly below a mold. A mold lubricant is sprayed on an interior surface of the mold cavity by actuating and rotating a mold lubrication nozzle mounted on a gear attached to a stationary circular plate of the loader and un-loader assembly. A bladder lubricant is sprayed on an outer surface of the bladder via a plurality of bladder lubrication nozzles mounted on an outer surface area of the stationary circular plate by moving the loader and un-loader assembly up and down with the bladder at a slightly inflated condition.
[0013] The mold lubrication nozzle mounted on the gear is rotated using an air motor and the mold lubricant is applied on the mold cavity. The bladder lubricant is sprayed on entire surface of the bladder by the bladder lubrication nozzles that is mounted on a mounting bracket and placed 60° apart from each other. The bladder lubricant is applied to a top surface of the bladder via the bladder lubrication nozzles by totally extending a top ring cylinder of the bladder with the bladder at a slightly inflated condition. The bladder lubricant is applied to a bottom surface of the bladder via the bladder lubrication nozzles by actuating a lower bead ring cylinder of the bladder so that the bladder with a lower ring moves up. The loader and un-loader

assembly and position of the lower ring is adjusted to lubricate the entire area of the bladder depending on height of the bladder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The disclosed embodiments may be better understood by referring to the figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.
[0015] FIG. 1 illustrates a cross-sectional view of a chuck assembly with a mold lubrication nozzle mounted on a gear, in accordance with the present invention;
[0016] FIG. 2 illustrates a front view of a loader and un-loader assembly with the mold lubrication nozzle in condition of spraying a mold lubricant inside a mold, in accordance with the present invention;
[0017] FIG. 3 illustrates an isometric view of a mold and bladder lubrication assembly with the mold lubrication nozzle and bladder lubrication nozzles, in accordance with the present invention;
[0018] FIG. 4 illustrates a front view of the loader and un-loader assembly at swing in and full up position with bladder lubrication nozzles and a bladder at slightly inflated condition, in accordance with the present invention;
[0019] FIG. 5 illustrates a front view of the loader un-loader assembly at swing in and full down position with the bladder lubrication nozzles and the bladder at slightly inflated condition, in accordance with the present invention;
[0020] FIG. 6 illustrates a front view of the loader and un-loader assembly at swing in and full down position with the bladder lubrication nozzles and the bladder at

slightly inflated condition and lower ring at fully extended condition, in accordance with the present invention;
[0021] FIG. 7 illustrates a top view of the mold and bladder lubrication assembly with the mold lubrication nozzle and the bladder lubrication nozzles, in accordance with the present invention;
[0022] FIG. 8 illustrates a side view of the loader and un-loader assembly with an LVDT for up/down position sensing, in accordance with the present invention;
[0023] FIG. 9 illustrates a perspective view of the bladder with a lower ring cylinder and a top ring cylinder, in accordance with the present invention; and
[0024] FIG. 10 illustrates a flow chart of operation depicting a method for lubricating a mold and bladder of a tire curing press, in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.
[0026] In the following, numerous specific details are set forth to provide a thorough description of various embodiments. Certain embodiments may be practiced without these specific details or with some variations in detail. In some instances, certain features are described in less detail so as not to obscure other aspects. The level of detail associated with each of the elements or features should not be construed to qualify the novelty or importance of one feature over the others.
[0027] The claimed subject matter has been provided here with reference to one or more features or embodiments. Those skilled in the art will recognize and appreciate that, despite of the detailed nature of the exemplary embodiments provided

here; changes and modifications may be applied to said embodiments without limiting or departing from the generally intended scope. These and various other adaptations and combinations of the embodiments provided here are within the scope of the disclosed subject matter as defined by the claims and their full set of equivalents. Like numbers refer to like elements throughout.
[0028] The present invention relates to a mold and bladder lubrication assembly and method for a tire curing press. This assembly pre-coats an inner surface of the mold and an outer surface of a bladder with a lubricant in order to provide lubricity between the outer bladder surface and the inner tire surface during the tire shaping and molding operation. This simple, efficient and reliable mold and bladder lubrication assembly and method is capable of applying the lubricant uniformly to the mold and bladder. The present invention is inexpensive, dependable and fully effective in accomplishing its intended purposes. The assembly is used to lubricate the tire curing presses that accommodate large variety of pneumatic tire sizes required for vehicles of different sizes, weights and performance characteristics.
[0029] Referring to FIG. 1 a cross-sectional view of a chuck assembly (6) with a mold lubrication nozzle (4) rotated by using a gear (14) and a motor (16) is illustrated, in accordance with the present invention. Note that in FIGS. 1-10, identical or similar parts or components are generally indicated by identical reference numerals. In general, a tire-curing press inserts green tires which are already in a shape close to a finished product into molds and shapes them into commercially available finished tires by applying heat and pressure. The tire curing process involves loading in of green tire into a mold (24) and unloading of cured tire out of the mold (24). This process is performed by a pick-up system placed on both the sides of a mold cavity (22).
[0030] The pick-up system consists of the chuck assembly (6) attached to an arm (8), which can swing radially up to a certain angle and slides along a vertical column (38). By the combination of both the radial and up-down traverse of the loader/un-loader arm (8), the tire is picked up from external units and placed into a

mold cavity (22) or vise-versa. Depending upon the nature of the process (before curing or after curing) this setup can be differentiated as a loader and un-loader assembly (2). A bladder (34) is disposed within the mold (24) and is inflated with air and deflated as required. The inflatable bladder (34) is made of rubber or another similar material, depending upon design considerations. The mold lubrication nozzle (4) is integrated with the loader and unloader assembly (2) to achieve the lubrication process.
[0031] Referring to FIG. 2 a front view of the loader and un-loader assembly (2) with the mold lubrication nozzle (4) in condition of spraying a mold lubricant (18) inside the mold (24), in accordance with the present invention. The loader and un-loader assembly (2) includes a stationary circular plate (12) having an inner surface (13) and an outer surface (30). A gear (14) is attached to the inner surface (13) of the stationary circular plate (12) of the loader and un-loader assembly (2) and actuated by the motor (16). The mold lubrication nozzle (4) is mounted on the gear (14) and is actuated by the motor (16) with a pinion (19). In a preferred embodiment, the mold lubrication nozzle (4) with the gear (14) and the motor (16) arrangement covers the entire or partial area of the mold (24), based on design consideration. The motor (16) can be for example, an air motor. In general, the pneumatic motor or air motor is a type of motor which does mechanical work by expanding compressed air. Air motors generally convert the compressed air energy to mechanical work through either linear or rotary motion.
[0032] The air motor (16) actuates the gear (14) so that the mold lubrication nozzle (4) mounted on the gear (14) rotates to spray the mold lubricant (18) from the mold lubrication nozzle (4) onto the interior surface of the mold cavity (22). The mold lubrication nozzle (4) uniformly sprays the mold lubricant (18) on the interior surface of the mold cavity (22) when the loader and un-loader assembly (2) swings inside the mold cavity (22) directly below the mold (24). A lubricant container (11) is attached to the vertical column (38) and connected to the mold lubrication nozzle (4) for spraying the mold lubricant (18) from the lubricant container (11) via the mold

lubrication nozzle (4) on the interior surface of the mold cavity (22). The lubricant container (11) releases the lubricant to the nozzle (4) where air and lubricant is mixed and sprayed onto bladder (34) or mold (24) . The mold lubricant (18) is applied inside the mold (24) before the start of curing the green tire. The coating of the mold (24) with the mold lubricant (18) improves the release of tires and reduces friction, therefore greatly improving finished tire appearance.
[0033] Referring to FIG. 3 an isometric view of a mold and bladder lubrication assembly (10) with the mold lubrication nozzle (4) and bladder lubrication nozzles (26A-26F) is illustrated, in accordance with the present invention. The mold and bladder lubrication assembly (10) further includes a plurality of bladder lubrication nozzles (26A-26F). The bladder lubrication nozzles (26A-26F) are mounted on a mounting bracket (28A-28F) attached to an outer surface (30) of the stationary circular plate (12) of the loader and un-loader assembly (2) and placed 60° apart from each other. In a preferred embodiment, six bladder lubrication nozzles (26A-26F) are attached to the loader and un-loader assembly (2) and placed 60° apart from each other to cover the entire area (360°) of the bladder (34), based on design consideration. It can be appreciated, of course, that the number of bladder lubrication nozzles (26A-26F) may vary based on the size and type of the tire curing presses.
[0034] The mold lubrication nozzle (4) and the bladder lubrication nozzles (26A-26F) is used in Passenger Car Radial (PCR) /Truck Bus Radial (TBR) tire curing presses and does not interfere with moving elements and green tire as the bladder lubrication nozzles (26A-26F) are mounted on the stationary circular plate (12) of the loader and un-loader assembly (2). The bladder lubrication nozzles (26A-26F) uniformly spray the bladder lubricant (32) to the outer surface of the bladder (34) when the loader and un-loader assembly (2) enters the mold cavity (22) and moves up and down with the bladder (34) at a slightly inflated condition.
[0035] Initially, the loader and un-loader assembly (2) swing in and move up with the bladder (34) at slightly inflated condition so that the bladder lubrication nozzles (26A-26F) spray the bladder lubricant (32) to the outer surface of the bladder

(34) as shown in FIG. 4. The lubricant container (11) attached to the vertical column (38) is also connected to each bladder lubrication nozzles (26A-26F) for spraying the bladder lubricant (32) from the lubricant container (11) via the bladder lubrication nozzles (26A-26F) on the outer surface of the bladder (34). The lubricant container (11) releases the lubricant to each nozzle (26A-26F). Each nozzle is supplied with lubricant and air which is mixed and sprayed onto the mold and bladder.
[0036] Referring to FIG. 5 a front view of the loader un-loader assembly (2) at swing in and full down position with the bladder lubrication nozzles (26A-26F) and the bladder (34) at slightly inflated condition is illustrated, in accordance with the present invention. The bladder (34) is composed of a lower bead ring cylinder (50) attached to a lower ring (48) and a top ring cylinder (42) attached to the top surface (55) of the bladder (34) as shown in FIG. 9. The top ring cylinder (42) of the bladder (34) is fully extended with the bladder (34) at slightly inflated condition so that the bladder lubrication nozzles (26A-26F) apply the bladder lubricant (32) to the top surface (55) of the bladder (34). Similarly, the lower bead ring cylinder (50) of the bladder (34) is actuated so that the bladder (34) with the lower ring (48) moves up. The bladder lubrication nozzles (26A-26F) then apply the bladder lubricant (32) to the bottom surface (56) of the bladder (34) to cover the entire surface of the bladder (34), as shown in FIG. 6. The bladder lubricant (32) is applied properly over the outer surface of the bladder (34) to provide smooth filling of the cavity, reduce energy consumption during the shot and extend the life of the bladder and mold.
[0037] FIG. 7 illustrates a top view of the loader and un-loader assembly (2) at swing in position with the bladder lubrication nozzles (26A-26F) and the bladder (34) at slightly inflated condition inside the chuck assembly (6), in accordance with the present invention. The loader and un-loader assembly (2) and position of the lower ring (48) is adjusted to lubricate the entire area of the bladder (34) depending on height of the bladder (34). The loader and un-loader assembly (2) and the lower ring cylinder (50) is composed of a linear variable differential transformer (52) to precisely position the loader and un-loader assembly (2) and the lower ring (48) for the lubrication process, as shown in FIGS. 8-9. In general, the linear variable differential

transformer (LVDT) is a type of electrical transformer used for measuring linear displacement (position). The bladder lubricant (32) is applied around the bladder (34) before the start of curing the green tire.
[0038] FIG. 10 illustrates a flow chart of operation depicting a method (70) for lubricating the mold cavity (22) and the bladder (34) of the tire curing press, in accordance with the present invention. The loader and un-loader assembly (2) is positioned inside a mold cavity (22) directly below a mold (24), as shown at block (72). The mold lubrication nozzle (4) mounted on a gear (14) attached to a stationary circular plate (12) of the loader and un-loader assembly (2) is actuated and rotated, as indicated at block (74). The mold lubricant (18) is uniformly sprayed on an interior surface of the mold cavity (22), as shown at block (76). The loader and un-loader assembly (2) is moved up and down with the bladder (34) at a slightly inflated condition, as illustrated at blocks (78). A bladder lubricant (32) is uniformly sprayed on an outer surface of the bladder (34) via a plurality of bladder lubrication nozzles (26A-26F) mounted on mounting brackets (28A-28F) attached to the stationary circular plate (12) that is placed 60° apart from each other, as indicated at block (74 (80).
[0039] The bladder lubricant (32) is applied to a top surface (55) of the bladder (34) via the bladder lubrication nozzles (26A-26F) by totally extending a top ring cylinder (42) of the bladder (34) with the bladder (34) at a slightly inflated condition, as shown at block (82). The bladder lubricant (32) is also applied to a bottom surface (56) of the bladder (34) via the bladder lubrication nozzles (26A-26F) by actuating a lower bead ring cylinder (50) of the bladder (34) so that the bladder (34) with a lower ring (48) moves up, as indicated at block (84). The loader and un-loader assembly (2) and position of the lower ring (48) is adjusted to lubricate the entire area of the bladder (34) depending on height of the bladder (34), as shown at block (86).
[0040] The application of the mold lubricant (18) and the bladder lubricant (32) to the mold (24) and the bladder (34) increases the lifetime of the bladder and mold and reduces the downtime for replacement. The assembly (10) can readily adapted to a

variety of ranges of operation, has a comparatively low cost of construction, is readily assembled, is accurate and reliable in operation, and and uniformly applies the lubricant than known prior art. Various alterations and modifications will occur to those skilled in the art from the foregoing detailed description of the invention and the accompanying drawings.
[0041] It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

We Claim:
1. A mold and bladder lubrication assembly (10) for a tire curing press having a
loader and un-loader assembly (2) for loading a green tire into a mold (24) and
unloading a cured tire out of the mold (24) via a chuck assembly (6) the mold and
bladder lubrication assembly comprising:
a mold lubrication nozzle (4) mounted on an actuatable gear (14) attached to an inner surface (13) of a stationary circular plate (12) of the loader and un-loader assembly (2) wherein the mold lubrication nozzle (4) uniformly sprays a mold lubricant (18) on an interior surface of a mold cavity (22) when the loader and un-loader assembly (2) swings inside the mold cavity (22); and
a plurality of bladder lubrication nozzles (26A-26F) attached to an outer surface (30) of the stationary circular plate (12) and placed equidistantly from each other wherein the bladder lubrication nozzles (26A-26F) uniformly sprays a bladder lubricant (32) to an outer surface of the bladder (34) when the loader and un-loader assembly (2) enters the mold cavity (22) and moves up and down with the bladder (34) at a slightly inflated condition.
2. The assembly as claimed in claim 1, wherein the plurality of bladder lubrication nozzles (26A-26F) are placed at 60° apart from each other.
3. The assembly as claimed in claim 1, wherein the chuck assembly (4) swings radially up to a certain angle and slides along a vertical column (38) of the loader and un-loader assembly (2).
4. The assembly as claimed in claim 1, wherein the vertical column (38) includes a lubricant container (11) connected to the mold lubrication nozzle (4) and the bladder lubrication nozzles (26A-26F) for spraying the lubricant to the interior surface of the mold cavity (22) and the outer surface of the bladder (34).

5. The assembly as claimed in claim 1, wherein the mold lubrication nozzle (4) with the gear (14) and a motor (16) arrangement covers the entire or partial area of the mold (24) and the mold lubrication nozzle (4) is moved on the gear (14) using the motor arrangement (16).
6. The assembly as claimed in claim 1, wherein the bladder lubrication nozzles (26A-26F) apply the bladder lubricant (32) to a top surface (55) of the bladder (34) by totally extending a top ring cylinder (42) of the bladder (34) with the bladder (34) at a slightly inflated condition.
7. The assembly as claimed in claim 1, wherein the bladder lubrication nozzles (26A-26F) apply the bladder lubricant (32) to a bottom surface (56) of the bladder (34) by actuating a lower bead ring cylinder (50) of the bladder (34) so that the bladder (34) with a lower ring (48) moves up.
8. The assembly as claimed in claim 1, wherein both the loader and un-loader assembly (2) and the lower ring cylinder (50) is composed of a linear variable differential transformer (52) to precisely position the loader and un-loader assembly (2) and the lower ring (48) for the lubrication process.
9. The assembly as claimed in claim 1, wherein the loader and un-loader assembly (2) and position of the lower ring (48) is adjusted so that the bladder lubrication nozzles (26A-26F) lubricate the entire area of the bladder (34) depending on height of the bladder (34).
10. A method for lubricating a tire curing press, comprising:
positioning a loader and un-loader assembly (2) inside a mold cavity (22) directly below a mold (24);
spraying a mold lubricant (18) on an interior surface of the mold cavity (22) by actuating and rotating a mold lubrication nozzle (4) mounted on a gear (14) attached to a stationary circular plate (12) of the loader and un-loader assembly (2); and

spraying a bladder lubricant (32) on an outer surface of the bladder (34) via a plurality of bladder lubrication nozzles (26A-26F) mounted on the stationary circular plate (12) by moving the loader and un-loader assembly (2) up and down with the bladder (34) at a slightly inflated condition.
11. The method as claimed in claim 9, comprising the step of spraying the lubricant inside the mold cavity (22) and the outer surface of the bladder (34) from a lubricant container (11) mounted on a vertical column (38) of the loader and un-loader assembly (2).
12. The method as claimed in claim 9, wherein spraying the mold lubricant (18) on the interior surface of the mold cavity (22), comprises:
rotating the mold lubrication nozzle (4) mounted on the gear (14) using a motor (16) and uniformly applying the mold lubricant (18) on the mold cavity (22).
13. The method as claimed in claim 9, comprising uniformly spraying the bladder lubricant (32) on entire surface of the bladder (34) by the bladder lubrication nozzles (26A-26F) that is mounted on a mounting bracket (28A-28F) and placed 60° apart from each other.
14. The method as claimed in claim 9, wherein spraying the bladder lubricant (32) to the outer surface of the bladder (34), comprises:
applying the bladder lubricant (32) to a top surface (55) of the bladder (34) via the bladder lubrication nozzles (26A-26F) by totally extending a top ring cylinder (42) of the bladder (34) with the bladder (34) at a slightly inflated condition.; and
applying the bladder lubricant (32) to a bottom surface (56) of the bladder (34) via the bladder lubrication nozzles (26A-26F) by actuating a lower bead ring cylinder (50) of the bladder (34) so that the bladder (34) with a lower ring (48) moves up.

15. The method as claimed in claim 9, comprising adjusting the loader and un-loader assembly (2) and position of the lower ring (48) to lubricate the entire area of the bladder (34) depending on height of the bladder (34).