GB2135057A

GB2135057A - Liquid level indicating apparatus with magnetic coupling arrangement

Info

Publication number: GB2135057A
Application number: GB08302998A
Authority: GB
Inventors: Chen Chieh-Ju
Original assignee: CHIEH JU CHEN
Current assignee: CHIEH JU CHEN
Priority date: 1983-02-03
Filing date: 1983-02-03
Publication date: 1984-08-22
Also published as: KR850002305A; GB8302998D0

Abstract

A liquid level indicating apparatus comprises a housing (11) having a central partition (12) dividing the housing (11) into a first chamber (13) and a second chamber (14). In the first chamber (13) there are a pair of fixed supporting members (16, 17), a wheel (19) on a shaft (15) rotatably mounted in the supporting members and carrying a horse-shoe magnet 18, and a flexible perforated tape (21) engaged with the wheel (19). In the second chamber (14) there are a supporting member (32), a magnetic follower (33) and a shaft (31) rotatably mounted in the supporting member (32), the follower (33) facing the magnet (18) in the first chamber (13), and a gear system (34, 35), together with a variable resistor (36). A float and a counter- weight are connected to respective ends of the flexible tape (21), so that, with the rise and fall of the float in the liquid container, the liquid level information can be transferred to a remote reading device. Magnetic shields (37, 38) can be provided. <IMAGE>

Description

SPECIFICATION Improved liquid level indicating apparatus with magnetic coupling arrangement This invention relates to an improved liquid indicating apparatus which is particularly dealt with magnetic coupling arrangement for automatically indicating the liquid level in a liquid container.

Conventionally, the known liquid level indicating apparatus used in a closed bulk container for petroleum company and chemical company is shown in Fig. 1, wherein the bulk container 10 has a floating body 11 arranged therein through a suspension line 1 2 secured at the middle of the floating body 11, and a pair of parallel lines 1 5 and 1 6 slidingly provided at both sides of the floating body 11 for making the up-and-down movement thereof in stable condition.The suspension line 1 2 is movably connected to an outside indicating instrument 1 3 through an arrangement of tightly closed detouring line pipes 14, which are designed for minimizing the infiltration of the gas from the container 10 into the indicating instrument 1 3 because the gas, if infiltrated into the indicating instrument 13, will be condensed therein, deteriorating the components of the instrument 1 3. In fact, as the detouring line pipes 14 are not completely closed, the aforesaid gas-infiltration problem is not solved yet.

In order to improve the defect of the known liquid level indicating apparatus as mentioned above, this inventor has designed a new liquid level indicating apparatus as shown in Fig. 2.

Application of this new liquid level indicating apparatus was filed in Taiwan in March 1981 with the serial No. 7023862 and has been allowed, and publication is under way in the official gazette at present. This apparatus comprises: a pulley 21 secured at the inner bottom of the container 20; a suspension line loop 22 is slidingly arranged between the pulley 21 and a rotary wheel 24 within the housing 31 of the liquid level reading unit 30 located at the top of the container 20 with one line secured at both ends 25 and 26 of the floating body 23 through a tension spring 27 and a pair of line pipes 33. The rotary wheel 24 is fixed around a rotating shaft 28, of which one end extends outwardly out of the housing 31 by forming a rocking handle 29 thereat, and the other end connected to a magnetic coupling unit 40, which is linked with a figure recording gauge 32.By rotating the rocking handle 29 for lifting the floating body 23 to the highest level of the liquid in the container 20 and holding it thereat, the liquid level can be read out from the figure recording gauge 32. With the completely closed magnetic coupling unit 40, which is isolated from the rotating shaft 28, this liquid level indicating apparatus can surely prevent the gas of the container 20 from infiltrating into the figure recording gauge 32.After practical utilization, however, some defects are found as follows: 1) As the pulley has to be provided at the inner bottom of the container, the abovementioned apparatus can be applied only to the newly constructed container but not to the old; 2) The alteration of the floating body is accomplished by means of line loop and rotary wheel, so that, when the line loop is rotated around the rotary wheel, slipping-off of the line loop will take place and cause trouble thereat; 3) Since the figure recording gauge is installed at the top of the container, liquid level can only be read off at the place of the container rather than knowing from remote control area; and 4) The structure of the magnetic coupling unit is bulky and complicated, incurring more manufacturing costs.

It is accordingly a primary object of this invention to provide an improved liquid level indicating apparatus with magnetic coupling arrangement for solving the above-mentioned problems and defects.

According to the present invention, this and other objects are achieved by providing an improved liquid level indicating apparatus which is characterized in that a housing structure has a partitioning member dividing the housing into two closed chambers, a first chamber and a second chamber. Elements installed in the first chamber include: a pair of fixed supporting plates symmetrically disposed therein; a rotary wheel matched with a driving shaft pivotally arranged between the supporting plates; a driving magnetic unit secured at one end; and a flexible slat having spaced holes formed in the middle matched with the rotary wheel.Elements installed in the second chamber include: a fixed support plate horizontally secured therein; a driven shaft rotatably installed in the middle of the supporting plate; a follower magnetic unit secured at one end of the driven shaft relative to the driving magnetic unit and the driving shaft in the first chamber through the partitioning member thereof; a gear system provided at the other end of the driven shaft; and a variable resistor coupled with the gear system in conjunction with the remote signal recording and reading device.A floating mechanism provided in the container is attached at both ends of the flexible slat, which is matched with the rotary wheel in the first chamber, so that, when the floating mechanism in the container moves up or down along with the liquid level thereof, it will cause the rotary wheel to rotate, which, in turn, causes the driving shaft and the driving magnetic unit thereof to make rotation. As a result, the follower magnetic unit in the second chamber will make a rotation along with the driving magnetic unit in the first chamber, and the rotating signals thereogf are transferred to the remote signal recording and reading device through the gear system and the variable resistor for level indicating and reading purpose.

Specifically, this invention resides in a pair of skid-stop elements separately provided at pre-determined places closing to the opposing sides of the rotary wheel for governing the slacking condition of the flexible slat, so that, when the liquid level in the container is in violent change, the abnormal condition of the floating body will not cause the flexible slat to skip over the rotary wheel.

This invention also resides in an arrangement of magnetic shielding elements provided around the magnetic units so as to prevent the magnetic units from being affected by the foreign magnetic field.

This invention resides still more in the structure of the rotary wheel which is provided with evenly spaced teeth along the middle central line of the wheel front face for being engaged with the correspondingly spaced holes of the flexible slat so as to ensure the rotation of the rotary wheel and the slat without causing skipping off.

This invention also resides still more in the arrangement of a pair of auxiliary sliding elements installed in conjunctiion with the movement of the flexible slat so as to keep the slat in smooth moving condition.

This invention resides still more especially in the arrangement of a speed change gear provided between the driven shaft and the variable resistor so as to eliminate the possible error caused by the driven shaft on account of the attraction and repelling action of the magnetic units thereof.

Other objects, characteristics and advantages of this invention will become clear from the following description of a preferred embodiment when read in conjunction with the accompanying drawings, in which: Figure 1 is a partial sectional view of a conventional liquid level indicating apparatus; Figure 2 is a partial sectional view of another known liquid level indicating apparatus; Figure 3 is a horizontal sectional view of a preferred embodiment of a liquid level indicating apparatus according to this invention; and Figure 4 is a cross sectional view of a first closed chamber of the preferred embodiment shown in Fig. 3.

Referring to Fig. 3, a preferred embodiment of an improved liquid level indicating apparatus with magnetic coupling arrangement according to this invention comprises in combination a housing structure 11 having a middle partitioning plate 1 2 provided therein in dividing the housing structure 11 into two tightly closed chambers-a first chamber 1 3 and a second chamber 14.Elements installed in the first chamber 1 3 include: a pair of fixed supporting plates 1 6 and 1 7 symmetrically disposed in horizontal position on the adjacent inner walls of the first chamber 13; a rotary wheel 1 9 having a plurality of evenly spaced teeth 20 integrally formed along the central line of the wheel front face, and a driving shaft fixedly installed in the centre pivotally connected to the centre of the supporting plate 1 6 at one end and through the centre of the supporting plate 1 7 at another end, to which a driving magnetic unit 1 8 in horseshoe shape is connected; and a cylindrical magnetic shielding member 37 installed on the partitioning plate 1 2 with the open end covering the magnetic unit 1 8 therein. Elements installed in the second chamber 14 include: a fixed supporting plate 32 horizontally secured on the adjacent inner walls of the second chamber 14; a driven shaft 31 rotatably disposed through the centre of the supporting plate 32 in axial line with the driving shaft 1 5 in the first chamber 1 3 and with bearing arrangement provided around the contacting area of the shaft 31 for smooth rotation; a follower magnetic unit 33 also in horse shoe shape rigidly mounted at one end of the shaft 31 with the open section exactly corresponding to the open section of the magnetic unit 1 8 across the partitioning plate 12; a cylindrical magnetic shielding member 38 secured on the partitioning plate 1 2 at one end corresponding to the opposite shield member 37, and the other end surrounding the magnetic unit 33; a set of differential gear system 34 and 35 connected to the other end of the driven shaft 31; and a variable resistor 36 coupled with the differential gear 35 thereof.

Referring to Figs. 3 and 4, elements associ a ted with the rotary wheel 1 9 include: a pair of skid-stop arms 23 and 24 respectively secured between the opposing sides of the supporting plates 1 6 and 1 7 at a pre-determined place closing to the opposing front sides of the rotary wheel 19; a flexible slat 21 having a plurality of evenly spaced holes 22 formed along the centre line movably coupled with the rotary wheel 1 9 by meshing the holes 22 with the teeth 20 of the rotary wheel 19, so that, moving the flexible slat 21 will drive the rotary wheel 1 9 to make same turns therefrom; besides, the moving condition of the flexible slat 21 is governed by the skidstop arms 23 and 24 so as to prevent the flexible slat 21 from skidding out of the front surface of the rotary wheel 1 9 when both ends of the flexible slat 21 are not in balance during abnormal moving condition; and a pair of auxiliary sliding wheels 25 and 26 respectively installed between the opposing sides of the supporting plates 1 6 and 1 7 below the rotary wheel 1 9 in conjunction with the flexible slat 21 so as to keep the slat in smooth moving condition thereat.As shown in Fiq. 4, a cross sectional view of the first chamber 13, a float body 27 in the container 1 is attached at one end of the slat 21 in the centre with a guide line 30, of which one end is connected to a dead weight 29 and the other fixed to the bottom of the housing 11, slidingly arranged thereat, and a moving weight 28 is connected at another end of the flexible slat for keeping the tensile strength at both ends of the slat 21 in balance during movement.

Operations of the preferred embodiment of this invention are as follows: When the liquid level in the container 1 changes, the floating body 27 will move up or down and drive the slat 21 to make the same movement along with the rotary wheel 19, from which the rotation will be transferd to the follower magnetic unit 32 through the magnetic force coupled between the magnetic unit 1 8 and the mangaetic unit 32, which, in turn, causes the differential gear system 34 and 35 to rotate through the driven shaft 31.

By means of speed change through the arrangement of the differential gear system 34 and 35, the rotation thereof is relayed to the variable resistor 36 for effecting the synchronized alteration of the resistance, which can be converted into analog signals through an analog signal converter (not shown) and fed into a reading device (not shown) so that liquid level can be known any time from remote area. Since the analog signal converter and the reading device are known arts, explanation is hereinafter omitted.

While a preferred embodimenth has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the

Claims

appended claims. CLAIMS

1. An improved liquid level indicating apparatus characterized by: a housing structure having a partitioning member dividing the housing into a first closed chamber and a second closed chamber; a pair of fixed supporting members symmetrically provided in said first chamber with predetermined spaces left therein; a rotary and driving mechanism movably connected to said supporting members in said first chamber; a fixed supporting member horizontally secured in said second chamber; a follower and driven mechanism movably connected to said supporting member in said second chamber in conjunction with said driving mechanism in said first chamber; a set of differentiating gear system rotatably connected to said driven mechanism in said second chamber;; a variable resistor coupled with said differentiating gear system in said second chamber for making sychronized change of resistance in accordance with rotation change of said gear system; a flexible slat coupled with said rotary and driving mechanism in said first chamber; and a floating mechanism in the liquid container connected to both ends of said flexible slat, so that, from the alteration of said floating mechanism along with the change of the liquid level in the container, liquid level information thereof can be exactly indicated through the rotations effected from said first chamber to said second chamber.

2. An improved liquid level indicating apparatus according to Claim 1 wherein said rotary and driving mechanism in said first chamber is further characterized by: a rotary wheel having a plurality of evenly spaced teeth formed along the central line of the wheel front face; a driving shaft fixedly installed in the centre of said rotary wheel with one end pivotally connected to the front side of one said supporting member and the other end rotatably extending through the middle of another supporting member; a horse-shoe magnetic unit secured at the extending end of said driving shaft; and a cylindrical magnetic shielding member secured on said partitioning member with the open section surrounding said horse-shoe magnetic unit for isolating possible foreign magnetic force thereto.

3. An improved liquid level indicating apparatus according to Claim 1 or 2 wherein said follower and driven mechanism in said second chamber are further characterized by: a driven shaft rotatably disposed through the centre of said supporting member in said second chamber in the same axial line with said driving mechanism; a follower magnetic unit in horse-shoe shape rigidly mounted at one end of said driven shaft with the open section corresponding to the open section of said horse-shoe magnetic unit in said first chamber across said partitioning member; and a cylindrical magnetic shielding member secured on said partitioning member with the open section surrounding said horse-shoe magnetic unit for isolating possible foreign magnetic force thereto.

4. An improved liquid level indicating apparatus according to Claim 1 ot 2 wherein said rotary and driving mechanism is further characterized by a pair of skid-stop members respectively secured between the opposing sides of said suppoting members in said first chamber and located at a pre-determined place closing to the opposing front sides of said rotary wheel so as to prevent said flexible slat from skidding out of the front surface of said rotary wheel during abnormal movement of said slat.

5. An improved liquid level indicating apparatus according to Claim 1 or 2 wherein said flexible slat is further characterized by having a plurality of evenly spaced holes formed along the central line for being meshed with said evenly spaced teeth along the central line of said rotary wheel so that when said flexible slat moves in either direction, it will drive said rotary wheel to make the same movement therefrom.

6. An improved liquid level indicating apparatus according to Claim 1 or 2 wherein said rotary and driving mechanism is further characterized by having a pair of auxiliary sliding wheels respectively installed between the opposing sides of said supporting members in said first chamber and located below said rotary wheel in conjunction with said flexible slat so as to keep the movement of said slat in smooth condiction thereat.

7. An improved liquid level indicating apparatus according to Claim 1 wherein said floating mechanism is further characterized in that: a float body attached at one end of said flexible slat in the centre for being placed on the liquid surface in the container; a guide line slidingly arranged through one end of said float body by tying one end of said guide line to a dead weight thereof in the container and fastening the other end to the bottom of said housing so as to keep said floating body in stable condiction; and a moving weight connected at another end of said flexible slat for keeping the tensile strength of said slat at both ends in balance during movement.

8. An improved liquid level indicating apparatus constructed and arranged substantially as hereinbefore described with reference to and shown in Fig. 3 and Fig. 4 of the accompanying drawings.