Disclosure of Invention Technical Problem [3] The integration type flow meter is expensive due to precision machining for high reliability, and is implemented in limited application area owing to the integration only functionality.

Technical Solution [4] To resolve the above-mentioned problems of the mechanical or electrical flow meters, it is therefore an object of the present invention is to provide a flow meter having following features: 1) Using for both integration and subtraction type ap- plication area by manipulating a reset means and a measurement selection means; 2) Durability to cope with the excessive rotational force or speed (3000-5000 rpm) acting on a rotor, as well as substantial sensitivity ; 3) Locking mechanism for preventing the reset means from malfunction; and 4) Providing substantial sealing between each components of a meter, compactness in structure, and portability.

[5] In order to achieve the object of the present invention, a flow meter having both in- tegration and subtraction functions comprises : a driving part including a rotor being rotated by the full force of the fluid flowing from the inlet to the outlet of a body, and a pinion being fixed at the rotational axis for said rotor; a slave part having gears that are actuated by said pinion of said driving part; a measurement selection part including a slider having rotational axes for an idle gear and the second gear connecting the first gear of the slave part engaging with said pinion and connecting to an axis for said slave part, and a selection lever capable of alternating the position of said slider ; a reduction gear train having a plurality of reduction gears engaging with said third gear of said slave part; and a meter part for measuring the residual or discharged volume of fluid by engaging the third gear of said slave part with either the second gear or an idle gear in accordance with manipulating said selection lever of said measurement selection part, and including a worm gear connecting to the last gear of said reduction gear train, and a digit roller having gears rotated by the gear engaged with said worm gear.

Advantageous Effects [6] The above-mentioned flow meter having both integration and subtraction func- tionality has advantages as followings: [7] 1. It is possible to utilize for both integration and subtraction type application by manipulating a reset part (70) and a measurement selection part (40) having a selection lever (41) capable of controlling a slider (45), thereby increasing users'convenience.

2. It has durability to cope with the excessive rotational force or speed (3000-5000 rpm) acting on a rotor (21a, 21b) which is shaped as the gear of a geared motor, as well as substantial sensitivity and easiness of manufacturing.

3. It has a locking mechanism (75,77) for preventing the reset part (70) from malfunction, thereby increasing the reliability of a flow meter.

4. It provides substantial sealing between each components, compactness in size, and portability. It is therefore easy to measure the volume of a fluid in various detachable place by connecting a flow meter to a conduit instantly.

[8] Although the explanation of the ordinary knowledge including the gear ratio, the reduction gear ratio, the prindple of digit roller has been omitted, it would be apparent to a person of skill in the art. Furthermore, while the embodiments illustrated in the figures are presently preferred, it should be understood that these embodiments are offered by way of example only. The invention is not intended to be limited to any particular embodiment, but is intended to extend to various modifications that nev- ertheless fall within the scope of the present invention. Accordingly different imple- mentations of the measurement selection part, the rotor shape as a geared motor, or reset means for the digit of a meter part that fall within the scope of the present invention would be apparent to those having ordinary knowledge and skill in the art.

Description of Drawings [9] Figure 1 is a partially sectioned, perspective view showing the driving part of a flow meter in accordance with the present invention.

[10] Figure 2 is a transverse sectional view illustrating the driving part of a flow meter in accordance with the present invention.

[11] Figure 3 is a fragmentary view showing the driving part of a flow meter in accordance with the present invention.

[12] Figure 4 is a fragmentary, exploded view illustrating the measurement selection part in accordance with the present invention.

[13] Figure 5 is a perspective view illustrating the reduction gear train in accordance with the present invention.

[14] Figure 6 is a perspective view showing the reset part and locking part of a flow meter in accordance with the present invention.

[15] <Reference number description of the drawings> [16] 10, 10a, 10b, lOc : body 20: driving part [17] 21a, 21b: rotor 23: packing [18] 25a, 25b, 25c, 25d: bearing 27: pinion [19] 30: slave part 31,33, 37: gear [20] 35 : idle gear 41 : selection lever [21] 40: measurement selection part [22] 43: anchoring part 43a: spring [23] 45 : slider 45a, 45b: rotational axis [24] 45c: guiding boss 50: reduction gear train [25] 51a, 51b, 51c, 51d, 53a, 53b, 54: reduction gear [26] 60: meter part 60a: frame [27] 61 : worm gear 70: reset part [28] 69a, 65b, 69c, 69d: digit roller LsJ 63,65a, 65b, 65c, 65d, 67a, 67b, 67c, 67d: gear [30] 71 : reset button 71a : button arm [31] 71b, 73b, 77b: elastic element [32] 73: reset plate 75: lock button [33] 77: guide bar 77a: locking boss [34] S 1, S2, S3, S4: rotational axis Best Mode [35] Hereinafter, referring to appended drawings, the structures and the operation procedures of the embodiments of the present invention are described in detail.

[36] In the present invention, a flow meter comprises : a body (10, 10a, lOb, 10c) shown in Figure 1 and Figure 2; a driving part (20) shown in Figure 2 and Figure 3 on which the flowing force acts directly ; the slave part (30) to which the rotation of the driving part is transferred, and the measurement selection part (40) shown in Figure 4, which makes the gear of the slave part rotate forward or reverse direction, thereby measuring the discharged or residual volume of fluid ; the reduction gear train (50) as shown in Figure 5 for reducing the rotational speed of the gear owing to the rapid fluid flowing, thereafter, for transferring the reduced speed to the following meter part (60); and a meter part (60) for displaying the measurement of the discharged or residual volume of fluid, the reset part (70) capable of controlling the digits of the meter part (60), and the lock button (75) for locking and unlocking the reset part (70) as shown in Figure 6.

[37] As illustrated in Figure 1 and Figure 2, the body (10) of a flow meter is composed of the upper (10a), middle (lOb), and lower (lOc) body part so as to manufacture and assemble easily. The middle body part (lOb) plays an important role for the fluid tight integrity between the upper and lower body part. Furthermore the fluid flows through the region between the lower (lOc) and middle (lOb) body part, but does not flows through the region between the upper (10a) and middle (lOb) body part.

[38] Only rotor (21a, 21b) taking the full force of the fluid flowing from the inlet (11) to the outlet (13) of the meter is positioned in the lower region, and the other components are separated from the liquid for preventing the flow meter from rusting and damaging.

[39] The reference notation B in Figure 1 indicates the fastening means for combining the upper, middle, and lower body part together. Furthermore, several holes are formed on the upper body (10a) as followings: a hole (15a) for a selection lever (41) of the measurement selection part (40), holes (15b) for digit rollers (69a, 6Sb, 69c, ó9d) of a meter part (60), a hole (17a) for the reset button (71) of a reset part (70), and a hole (17b) for a lock button (75). A suitable cover is placed over holes (15b) for the digit rollers (69a, 6GD, 69c, 69d), thereby preventing rollers from contamination, damage, and malfunction.

[40] Next, in a driving part (20) as shown in Figure 2 and Figure 3, a rotating rotor taking the full force of the fluid flowing can be single as the rotor of a general water meter or a impeller. However, in the present invention, the rotor is formed as the gear shape of a general geared motor so as to guarantee the durability to cope with the excessive rotational force or speed (about 3000-5000 rpm) acting on a rotor, as well as easy manufacturing and substantial sensitivity.

[41] Accordingly, one rotor (21a) is mounted on the same rotational axis (S 1) with a pinion (27) transmitting the rotational force to a slave part (30) of Figure 4, the other rotor (21b) is rotated as an idle gear with respect to the rotational axis (S2).

[42] Particularly, in the structure of a flow meter comprised of the upper, middle, and lower body part (10a, lOb, lOc), the rotor 21a is isolated from the pinion (27) positioned in the upper region of a body by means of the middle body part (lOb). The packing (23) is placed to protect for the liquid to flow into the upper region of the body through a hole (not shown) for the rotational axis (S 1).

[43] Bearings (25a, 25b, 25c, 25d) are employed on each rotor (21a, 21b). To prevent the liquid from influendng bearing (25a), the upper bearing (25a) of a rotor (21a) is placed over the packing (23). It is desirable to place suitable packing for the other bearings (25b, 25c, 25d). The bearings (25a, 25b, 25c, 25d) can be replaced with bushings by the consideration of the easiness of manufacture and the rotational speed (under 2000 rpm).

[44] A slave part (30) connecting with the pinion (27) of a driving part (20) in Figure 3, is connected to the measurement selection part (40) of Figure 4, which let users select the integration or subtraction type of measurement.

[45] The slave part (30) is comprised of a first gear (31) connecting to the pinion (27), a second gear (33), a third gear (37), and an idle gear (35).

[46] The rotational axis (S3) of the first gear (31) is fixed on the body, and the rotational axes (45a, 45b) of the second gear (33) and the third gear (37) are connected to the slider (45) of the measurement selection part (40).

[47] The first gear (31) and the second gear (33) function as the reduction gear, and the second gear (33) is engaged with the idle gear (35). The third gear (37) is engaged with either the second gear (33) or the idle gear for either integration or subtraction operation, respectively, according to positioning of the slider (45) of the measurement selection part (40).

[48] Generally, it is desirable to engage the third gear (37) with the second gear (33) instead of the idle gear (35) for the subtraction operation, because the flow meter in accordance with present invention would be mainly utilized for the subtraction type application. In this description, we assume that the rotational direction of the third gear (37) during the subtraction operation engaging the second gear (33) with the third gear (37), is defined as forward direction. The rotational direction of the third gear (37) during the integration operation is, of course, defined as reverse direction.

[49] Next is the description of a measurement selection part (40), one of the cores of the present invention.

[50] A slider (45) is connected to the axis (S3) for the first gear of a slave part (30). It comprises rotational axes (45a, 45b) for an idle gear (35) and for the second gear (33) connecting the first gear (31) of the slave part (30) which is engaging with the pinion (27) of a driving part (20), respectively.

[51] By alternating the position of a slider (45) using a selection lever (41), the third gear (37) of the slave part (30) is engaged with either the second gear (33) or the idle gear (35). Figure 4 illustrates that the selection lever (41) is connected with a slider (45) via the rotational axis (45a) for the second gear (33). However, the present invention is not limited to the drawing described above.

[52] Furthermore, the top area of a selection lever (41) is connected to an anchoring part (43) having a spring array (43a) to restrict the movement of a selection lever (41). The measuring stage selection by a lever (41) with the help of a spring is achieved by utilizing a boss or an elastic boss of an anchoring part (43). The selection lever (41) may move between three stages including'integration','neutral', and'subtraction'. If the neutral stage is selected, the third gear (37) of a slave part (30) is connected neither the second gear (33) nor the idle gear (35), thereby staying the following gears after said third gear (37).

[53] The reference notation S4 denotes an axis for the third gear (37), and 41a illustrates a hole formed on the lever (41) for connecting to the proper handle.

[54] A guiding boss (45c), which is inserted into a guiding groove (not shown) formed on the body of a flow meter, is protruded at the lower region of the slider (45) of a measurement selection part (40). With the help of a guiding boss and groove, the smooth movement of the selection lever (41) and a slider (45) can be achievable. It is desirable that the guiding boss (45c) is built on the same rotational axis (45b) for the idle gear (35) for easy manufacturing.

[55] Although high rotational force (rotational speed) transmitted from rotors (21a, 21b) is reduced to some extent by means of gears (31,33) of a slave part (30), the present invention proposes to utilize a reduction gear train (50) connecting to the third gear (37) of a slave part (30), so as to gain the higher speed reduction ratio. The reduction gear train (50) is composed of several reduction gears (51a, 51b, 51c, 51d, 53a, 53b, 54).

[56] Figure 6 illustrates a meter part (60) and a reset part (70) in accordance with the present invention. The initial force transmitted from the reduction gear train (50) is applied to a worm gear (61) that is connecting to the last gear (54) of a reduction gear train (50) in Figure 5. Thereafter, the rotational force is transmitted to gears (67a, 67b, 67c, 67d) attached on digit rollers (69a, 69s, 69c, 69d) through the gear (63) engaging with a worm gear (61).

[57] Particularly, the connection between the gears (67a, 67b, 67c, 67d) of digit rollers (69a, 69b, 69c, 69d) and the gear (63) engaging with a worm gear (61) is relayed by in- termediate gears (65a, 65b, 65c, 65d).

[58] An intermediate gear 65a engages with both a gear 63 and a gear 67a, and transmits firstly the rotational force delivered from worm gear (61) to a digit roller 69a. If a digit roller 69a rotates 10 times, an intermediate gear 65b rotates one time, consequently the gear 67b of a digit roller 65b rotates one time. Accordingly, 10 revolutions of a digit roller 69 leads to 1 revolution of a digit roller 69c, and 10 revolutions of a digit roller 69c leads to 1 revolution of a digit roller 69d.

[59] Each roller (69a, 69b, 69c, 69d) may denote 1,10, 100, and 1000 liter unit in the metric system, and also a roller 69a and a roller 69b may denote the decimal place numbers such as milliliter in metric system. However, the number of rollers, the decimal point, and the measurement unit system can be selected arbitrarily without any limitation.

[60] The rotational axes for every gears and rollers except a worm gear (61) in a meter part (60) are mounted on a frame (60a), and four bosses are installed at four comers of the frame (60a) for the purpose of fixing components in the body (10a, lOb).

[61] Also, Figure 6 illustrates a reset part (70) of a flow meter in accordance with the present invention. A reset plate (73) of the reset part (70) is connected to the frame (60a) for the meter part (60), and the rotational axes for intermediate gears (65a, 65b, 65c, 65d) of the meter part (60) are installed on the reset plate. The force of a spring (73b) presses the plate at normal stage, thereby engaging intermediate gears (65a, 65b, 65c, 65d) with each gear (63, 67a, 67b, 67c, 67d).

[62] By pressing reset button (71), the plate (73) is pushed down, and consequently in- termediate gears (65a, 65b, 65c, 65d) and each gear (63, 67a, 67b, 67c, 67d) are separated.

[63] In other word, the reset button (71) is constrained by the spring (71b) installed at the lower region in normal stage. When user pushes the reset button (71), a button arm (71a) moves downward, consequently a boss (73a) on the plate is pushed, and the plate (73) moves downward against the spring (73b), thereby separating intermediate gears (65a, 65b, 65c, 65d) from each gear (63, 67a, 67b, 67c, 67d).

[64] The spring (71b) under the reset button (71) is connected to a latch (71c), and this latch (71c) may reach to the upper body part (lOa).

[65] In Figure 6, the lock button (75) for locking or unlocking the reset part (70) is connected to a guide bar (77) that is constrained by the spring (71b), and the guide bar moves along the guide groove (refer to Figure 1) that is formed on the body (10).

[66] Because the locking boss (77a) of a guide bar (77) touches a latch (71c) formed under the reset button (71) at normal stage, the reset button (71) can not be pushed down. However, when user slides the lock button (75) toward the spring (77b), the locking boss (77a) of a guide bar (77) also slides toward the spring thereafter, the latch (71c) of a reset button (71) can be pushed down.

[67] The lock button (75) has a similar operating principle as that of a ballpoint pen: If user pushes the lock button toward a spring (77b), it holds a guide bar as pushed. If user pushes the lock button again, the guide bar is relaxed and back to an initial position.

[68] By pressing the reset button (71) after the lock button (75) is moved toward a spring, a latch (71c) of a lock button (75) moves into the receiving groove (77c), con- sequently it is possible that a button arm (71a) pushes the boss (73a) of the reset plate (73). Thereafter, an user can adjust the digit rollers (69a, 69b, 69c, 69d) because in- termediate gears (65a, 65b, 65c, 65d) are separated from each gear (63,67a, 67b, 67c, 67d).

[69] The digit rollers are set by 0 for an integration type application, while set by the specific numbers in accordance with the volume of the liquid in the tank for a subtraction type application.

[70] From now on, the operating principle and effectiveness of a flow meter having dual functions such as the integration and subtraction measurement in accordance with the present invention will be discussed.

[71] First, a pipe or hose is connected to the inlet and outlet of a flow meter. A user can set the selection lever (41) at RES (residual) position for subtraction type application, and adjust the digit rollers (69a, 69 ?, 69c, 69d) as the desired number, while pressing the reset button (71) and the lock button (75). As the fluid starts to flow into the flow meter, the third gear (37) of a slave part (30) engages with the second gear (33) rotates toward the forward direction.

[72] The rotation of rotors (21a, 21b) actuated by the flowing of fluid is transmitted to the following elements sequentially : a pinion (27) in Figure 3--> the first gear (31)--> the second gear (33)--> the third gear (37) of a slave part (30) in Fisure 4--> reduction gears (51a, 51b, 51c, 51d, 53a, 53b) of a reduction gear train (50) and the last gear (54) in Figure 5--> a worm gear (61)--> a gear 63--> an intermediate gear 65a--> a gear 67a--> a roller 69a--> an intermediate gear 65b--> a gear 67b--> a roller 6S an intermediate gear 65c--> a gear 67c--> a roller 69c--> an in- termediate gear 65d--> a gear 67d--> a roller 69d in Figure 6. Thereafter, the number indicated by digit rollers (69a, 69b, 69c, 69d) is reduced gradually, and become to zero when the liquid in a tank is discharged completely.

[73] For reset operation of the meter part, a user may unlock a lock button (75) and move a reset plate (73) down by pushing a reset button (71). Thereafter, the user can adjust the digit rollers (69a, 69b, 69c, 69d) to zero or the desired number manually because intermediate gears (65a, 65b, 65c, 65d) are separated from each gear (63,67a, 67b, 67c, 67d).

[74] Next, a user can set the selection lever (41) at INT (integration) position for in- tegration type application. The inflow of fluid makes rotors rotate, and the rotational force of rotors is transmitted to the following elements sequentially as similar manner of the subtraction operation, except the first gear (31)--> the second gear (33)--> the idle gear (35)--> third gear (37) of a slave part (30) in Figure 4. In this operation, the gears including the third gear and following gears after the third gear rotate toward the reverse direction. Accordingly, the number indicated by digit rollers (69a, 69b, 69c, 69d) is increased gradually.

[75] When a user positions the selection lever (41) at the N (neutral) stage, the third gear (37) of a slave part (30) is connected neither the second gear (33) nor the idle gear (35). Therefore, a flow meter functions as the bypass that does not measure the flow rate during some extent of time.