WO2000049375A1

WO2000049375A1 - Personal weighing scale with mechanical sensor

Info

Publication number: WO2000049375A1
Application number: PCT/HU1999/000031
Authority: WO
Inventors: László URBÁN; János FARKAS
Original assignee: Magyar Optikai Mûvek Elektromechanikai Rt.
Priority date: 1999-02-18
Filing date: 1999-04-23
Publication date: 2000-08-24
Also published as: AU3723699A; HU9901330D0; HU1842U; HU9900037V0

Abstract

Personal weighing scale having a lower part (1), an upper load-platform (14), a mechanical load weighing device between them, and a display, wherein the mechanical load weighing device contains long arms (8) and short arms (15) connected to each other, the lower part (1) is provided with supporting legs (2) and connecting springs (18) are arranged between the load-platform (14) and the lower part (1), the middle portions of the long arms (8) are provided an opening (19) having a-height facing knife-edged lower portion and the short arms (15) have at their connecting ends a portion (20) of a height (H1) less than the minimal height (Hmin) of the opening (19), this portion (20) being provided with projections (21) and the heights of short arms (15) adjacent the projections (21) is greater than the maximal height (Hmax) of the opening (19), but is smaller than the width (S) of the openings (19). The supporting legs (2) are consoles secured to the frame to overhang the annular frame both upward and downward, each of connecting springs (18) is stretched outside the periphery of the frame, directly between a supporting leg (2) and a corresponding tilting plate holder (16) secured to the load-platform (14).

Description

PERSONAL WEIGHING SCALE WITH MECHANICAL SENSOR

The present invention relates to mechanical personal weighing scales having a lower part, an upper load-platform, a mechanical load weighing device between them, and a display, wherein the mechanical load weighing device contains long and short arms connected to each other, the lower part is provided with supporting legs and connecting springs are arranged between the load-platform and the lower part.

Currently, the weighing device between the lower part and the load-platform of mechanical personal scales used in bathrooms are provided with measuring spring resiliently deformed due to the load affecting directly to the load-platform. The measured value is proportional to the deformation and appears in a display.

In the case of personal scales provided with mechanical weighing device the load detecting mechanism contains two pairs of arms, which bear the load platform by tilting plates on said tilting plate, said knife edge facing downwards and resting in a V-shaped recess of the arms, there are knife edges on the tilting plates, facing upwards and supporting a tilting plate holder, which is glued or otherwise fixed to the load-platform.

The load-platform is held by connecting springs fixed in the lower part of the scale. The load-platform is provided with supporting elements, such as legs.

Commonly, in the case of such scales, the two long arms are connected at one of their ends by means of a plate, thus forming a single V shaped lever. The other ends of the arms are placed in the recesses formed at the two opposite side angle of the lower part. The plate is supported by a spring element. The two first ends of the shorter arms are placed in the recesses formed at the other side of the lower part and their second ends are connected with buckles to the V shaped recesses of the longer arms. The buckles are substantially ring shaped parts adapted onto the recesses of the longer arms. Although, this conventional construction enables a good power train, its mounting is a very compli- cated process, since the buckles have to be drawn along the longer arms up to the recess and bedding-in of the ends of short arms takes place in an artless and time-consuming way.

A known solution in the prior art is providing a recess on the upper edge of the longer arms. The free end of the shorter arms are inserted into this recesses, thus the mounting shall be simpler than the conventional way above, but this type of connection disconnects easily in use, in case of occasional shock-like loading.

The load-platform of scales with weighing device is often made of glass, which enables the observation of the inside mechanism in work. The load platforms may have square or oval shape. The tilting plate holders are glued to the glass load-platforms.

The object of the present invention is to provide an aesthetic, well-formed and easy-to-fit personal scale having a mechanism with excellent reliability of service, which may be applied for personal scales provided with load-platforms made of glass. Accordingly, the personal scale according to the invention is provided with mechanical load weighing device containing a lower part, an upper load-platform, a mechanical load weighing device between them, and a display, wherein the mechanical load weighing device contains long and short arms connected to each other, the lower part is provided with supporting legs and connecting springs are arranged between the load-platform and the lower part, the middle portions of the long arms are provided an opening having an aheight facing knife-edged lower portion and the short arms have at their connecting ends a portion of a height (H1 ) less than the minimal height (H_m,„) of the opening, this portions being pro-_ vided with projections and the height of short arms adjacent the projections is greater than the maximal height (H_max) of the opening, but is smaller than the width of the openings.

Another variant of the personal scale according to the invention contains a lower part and a load platform provided with appendages secured to the lower side of the platform, as well as a load detecting mechanism placed between them and a display unit, the load detecting mechanism has short and long arms connected to each other, the lower part contains a frame and legs forming consoles overhang- ing the periphery of the frame and the contractive springs connecting the lower part and the frame to each other are stretched outside the frame, directly between a supporting leg and a corresponding projection-like tilting plate holder secured to the load platform for the purpose of relieving the frame. Consoles are formed as bent and/or welded plate structures and the frame has an annular shape and contains a hollowed-out structure.

The first end of each connecting spring is in a bore in the tilting plate holder and the second end thereof is set to a detent of said supporting legs.

The longitudinal axis of the cylindrical tilting plate holders are arranged perpen- dicular to the load-platform, and are provided with a pair of longer recesses and a pair of shorter recesses between a central cavity and the other surface of said tilting plate holder along two diameters perpendicular to each other, where in the arms are arranged in the longer recesses, first and second knife-edge of the tilting plate supported by the arms by third knife-edge thereof are arranged in the shorter recesses.

The tilting plates are fork-shaped elements and the knife-edges are parallel to the plane of the tilting plate so that one of the knife-edges embedded into the arms is between the teeth of the fork, and the other two knife-edges embedded into the recesses of said cylindrical tilting plate holder on the projections of the outer side of the teeth, opposite to the first knife-edge.

In a further preferred embodiment the load-platform is a round, square or oval shaped platform, preferably made of glass and the tilting plate holders are glued to the lower surface of the load-platform.

The present invention enables an easy assembling the longer and shorter arms to each other by a single movement and without jumping, due to the absence of the buckles used in the conventional constructions.

The tilting plate holder according to the present invention has an aesthetic configuration, connecting parts of the arms and tilting plates are arranged inside the wall of the holder, its assemblage is easy and it prevents disconnection of the parts in use. An other advantage of the present invention is , that the forces resulting from the load are transmitted from the holder directly to the supporting legs, thus the developed forces affect directly to the ground and the lower part bearing only a small portion of the load, thus avoiding the strain of the lower part jeopardizing meas- urement accuracy.

The advantages of the invention will become clearer from the following detailed description of a preferred embodiment thereof, described by way of noπ limiting examples with reference to the appended drawings, in which:

Figure 1 is a top-side view of a preferred embodiment of the scale according to the present invention,

Figure 2 is an elevation view of the scale shown in Figure 1 ,

Figure 3 is an end-view of the scale shown in Figure 1 -2,

Figure 4 is an exploded view of the scale shown in Figure 1-3,

Figure 5 shows the connection of the arms,

Figure 6 shows the recess formed on a longer arm,

Figure 7 is an enlarged view of the connection shown in Figure 5,

Figure 8 is an exploded view of a tilting plate holder and the tilting plates connected thereto,

Figure 9 shows the assembly of Figure 8.

Figures 1 to 3 show the top -side view, elevation view and end-view of a preferred embodiment of the scale according to the present invention. The mechanism of the scale can be seen in Figure 4.

The lower part 1 of the scale comprises a hollowed out disk made of metal. It is provided with symmetrically arranged supporting legs 2. Levelling screws 3 are applies holding the scale in horizontal position. Bridge 4 keeping together the parts of the weighing device is connected to the lower part 1. Bridge 4 is provided with a null-balance device 5 and a measuring spring 6 connected to the latter. One end of the 6 measuring spring is fixed in the 5 null-balance device, the other end is held by supporting plate 7 connected to longer arms 8 arranged in V shape. Beam 9 in bridge 4 and rack 10 connected to the beam 9 with a cogged shaft 11 transform the vertical displacement of the supporting plate 7 into a circular motion,. One end of the cogged shaft 11 is guided in the bridge 4, the other end is guided in a bearing plate 12. The free end of cogged shaft 11 is provided with a conventional indicator dial 13.

The load-platform 14 made of glass and is provided with tilting plate holders 16 glued thereto. Tilting plate holders 16 bear on the V shaped recesses of the short arms 15 and long arms 8 by means of tilting plates 17. Connection springs 18 keeping together the load-platform 14 and lower part 1 are extended between the tilting plate holders 16 and supporting legs 2 of the lower part 1.

The ends of the short arms 15 are held by an opening 19 in the middle of the long arms 8 (see Figures 5-7).

Figure 5 shows the connection between the long arms 8 and short arms 15. In the middle each of the long arms 8 an opening 19 is formed as shown in Figure 6. Portions 20 of decreased height formed on the ends of short arms 15 are held on the knife edged lower part of the opening 19 (see Figure 7).

Portion 20 of decreased height has a projection 21 at the end, for preventing the disconnection of short arm 15 from the opening 19 of the long arm 8. For this purpose, the height H2 of the projection 21 is higher than the maximal height H_max of opening 19. In order to enable easy mounting of long arms 8 and arms 15, the height H1 of portion 20 of decreased height must be lower than the minimal height H_min of the opening 19. At the same time the height H2 of the projection 21 must be smaller than the width S of the opening 19. Connecting the two parts to each other may be realized by a single movement and without jumping. Turning off short arm 15 by an angle of 90° with respect to the long arm 8 portion 20 of decreased height with projection 21 can easily be inserted to the opening 19 of the long arm 8. Then the short arm 15 should be turned off to a vertical position. Thus the portion 20 of decreased height is held by the knife-edged lower surface of the opening 19. Consequently, the short arm 15 is protected 8 by projection 21 against jumping off from the opening 19 of the long arm. Jumping free, frictionless displacement of the engaged short arm 15 is enabled by knife-edged lower portion of opening 19 of the long arm 8. The length of force arm is also held in a constant value.

Figure 8 shows that part of the scale, in which the load-platform 14 and support- ing leg 2 secured to the lower part 1 are connected by connecting spring 18 through the tilting plate holder 16 glued to the load platform 14.

Tilting plate holder 16 is a cylindrical element provided with a central cavity and having two pairs of grooves 22, 23 formed at an angle of 90° relatively to each other. The long arms 8 and short arms 15 are arranged in the longer grooves 22. The lower knife-edges 24 of tilting plate 17 are held in the shorter grooves 23. Knife-edges 24 are formed on the lower projections of the fork-shaped teeth of a tilting plate 17, opposite to the upper knife-edges 25 between the teeth. Knife- edges 25 are held in the V shaped recesses of long arms 8 and short arms 15, respectively. Upper end of the connecting spring 18 is held in a hole 26 in the wall of tilting plate holder 16 and its lower end is held by a detent 27 formed in the supporting leg 2. Thus, the connection between load-platform 14 and the lower part 1 is safe. Furthermore, the mechanism is visible during the use, since the connecting parts are arranged substantially inside the tilting plate holder 16. The construction dis- closed above can be easily mounted and inadvertent jumping off the mounted parts can be avoided.

Figure 9 shows the parts shown i Figure 8 in a fitted state. The load is transmitted by tilting plate holder 16 to the mechanical weighing device by means of tilting plate 17. The elements of the weighing device however are hidden and, as a fur- ther advantage, the developed forces are transmitted by supporting legs 2 directly to the ground. Thus, deformation of the lower part 1 and jeopardizing measurement accuracy is avoided.

Although the present invention has been described with reference to a single embodiment, rearrangements an modifications can be made and still the solution would within the scope of the design. Instead of square shaped solution discussed above the load-platform may be rounded, oval or may have any aesthetic form. In a preferred embodiment the material of load-platform is glass, bat it may be made of any other material i.e. marble, plastic or metal. Instead of a ring shaped lower part 1 , the lower part 1 also may have other aesthetic and decorating hollowed out form. The parts of the mechanism may have either polished, flatted, eloxed, painted surfaces or surfaces treated in any other way.

Claims

1. Personal weighing scale having a lower part (1 ), an upper load-platform (14), a mechanical load weighing device between them, and a display, wherein the mechanical load weighing device contains long arms (8) and short arms (15) connected to each other, the lower part (1 ) is provided with supporting legs (2) and connecting springs (18) are arranged between the load-platform (14) and the lower part (1 ), characterized in that, the middle portions of the long arms (8) are provided an opening (19) having an aheight facing knife-edged lower portion and the short arms (15) have at their connecting ends a portion (20) of a height (H1 ) less than the minimal height (H_min) of the opening (19), this portions (20) being provided with projections (21 ) and the height of short arms (15) adjacent the projections (21 ) is greater than the maximal height (H_max) of the opening (19), but is smaller than the width (S) of the openings (19).

2. Personal weighing scale having a lower part (1 ), an upper load-platform (14), a mechanical load weighing device between them, and a display, wherein the mechanical load weighing device contains long arms (8) and short arms (15) connected to each other, the lower part (1 ) is provided with supporting legs (2) as well as a frame and connecting springs (18) connected to projections (21 ) are arranged between the load-platform (14) and the lower part (1 ), characterized in that, the supporting legs (2) are consoles secured to the frame to overhang the annular frame both upward and downward, each of connecting springs (18) is stretched outside the periphery of the frame, directly between a supporting leg (2) and a corresponding tilting plate holder (16) secured to the load-platform (14).

3. Personal weighing scale according to claim 2, characterized in that, the consoles are formed as bent and/or welded plate structures.

4. Personal weighing scale according to claim 3, characterized in that, the frame has a hollowed-out structure.

5. Personal weighing scale according to any of the claims 2 to 4, characterized in that, the frame is of annular shape.

6. Personal weighing scale according to any of claims 2 to 5, characterized in that, first end of each connecting spring (18) is in a bore (26) in the tilting plate holder (16) and the second end thereof is set to a detent (27) of said supporting legs (2).

7. Personal weighing scale according to any of claims 1 to 6, characterized in that, the longitudinal axis of the cylindrical tilting plate holders (16) are arranged perpendicular to the load-platform (14), and are provided with a pair of longer recesses (23) and a pair of shorter recesses (22) between a central cavity and the other surface of said tilting plate holder (16) along two diameters perpendicular to each other, where in the arms (8,15) are arranged in the longer recesses (22), first and second knife-edge (24) of the tilting plate (17) supported by the arms (8,15) by third knife-edge (25) thereof are arranged in the shorter recesses (23).

8. Personal weighing scale according to claim 7, characterized in that, the tilting plate (17) is a fork-shaped element and the knife-edges (24,25) are parallel to the plane of the tilting plate (17) so that one of the knife-edges

(25) embedded into the arms (8,15) is between the teeth of the fork, and the other two knife-edges (24) embedded into the recesses (23) of said cylindrical tilting plate holder (16) on the projections of the outer side of the teeth, opposite to the first knife-edge (25).

9. Personal weighing scale according to any of the claims 1 to 8, characterized in that, the load-platform (14) is a round, square or oval shaped platform, preferably made of glass.

10. Personal weighing scale according to claim 9, characterized in that, tilting plate holders (16) are glued to the load-platform (14).