WEIGHING DEVICE, E.G. FOR WEIGHING LIVESTOCK

Abstract: A weighing device comprising a frame with two side beams (11, 12), which are connected by a cross member (13). To make sure that all of the four feet (15) provided at the ends of the side beams (11, 12) bear against a foundation, even if the foundation is uneven, the side beams are turnable arranged around the axis (14) of the cross member (13). A walking plane (19) for the load to be weighed is mounted between the side beams (11, 12) and is so fixed to the side beams that the walking plane (19) follows the movement of the side beams as they adjust to the foundation.

Description: Weighing device, e.g. for weighing livestock The invention relates to a weighing device comprising two essentially straight side beams of equal length and positioned in parallel at a distance from each other, said side beams supporting between themselves a walking plane for the load to be weighed and being provided with a foot at each of their ends to bear against a foundation, said feet being connected to a device for measuring the weight of the load. Such a weighing device is known from the PCT patent publication W0 81/01196. This known scale has two parallel side beams and a walking plane (p. 7, last paragraph), mounted across the side beams. The scale bears against the foundation on four feet. Since the structure is rigid, the feet are adjustable in the vertical direction so that the structure can be brought to rest on all feet against the foundation in order not to wobble and frighten an animal which climbs, stands on or moves on the walking plane. The object of the invention is to achieve a weighing device, which is easy to handle in that it is light and adjusts itself to the foundation without manual adjustment of said feet to bring the scale in a steady ppsition. A further object of the invention is to achieve a weighing device, which has a robust structure to give a reliable performance. -The invention is characterized in that the side beams are movably mounted with respect to each other in essentially parallel planes, going through the longitudinal axis of the side beams and being perpendicular to the foundation so that, when putting the scale against an uneven foundation, all four feet will bear against the foundation, the walking plane being arranged to follow the movement of the side beams as they adjust to the foundation. that the walking plane wobbles with respect to the side beams and frightens an animal which-climbs, stands or moves on the walking plane. According to one embodiment of the invention. the side beams are connected by a cross member, which permits the side beams to twist with respect to each other around the longitudinal axis of the cross member. To achieve the desired mobility of the side beams with respect to each other, there is only needed a comparatively light cross member of simple design. According to a further embodiment of the invention, the cross member is constituted by an open profile bar, which is relatively flexible for twisting around its longitudinal axis and which is connected at both its ends with each of the side beams. This is an extremely light and simple cross member to achieve a desired mobility of the side beams with respect to each other. According to still another embodiment of the invention, the cross member is connected to the side beams at one pair of ends of the side beams and the other pair of ends of the side beams are connected by a cross beam, which permits a restricted twisting movement of the side beams around the longitudinal axis of the cross member. The cross beam restricts the twisting movement of the side beams sufficiently to eliminate the risks for breaking away the walking plane from the scale and, in case the cross member is constituted by a flexible profile bar, to avoid permanent deformation of the profile bar. The cross beam and the cross member may further constitute support for or being part of the walking plane at the ends thereof. The cross beam can be mounted very low, and thereby one end of the walking plane can be mounted on low height above the foundation to facilitate climbing for an animal or rolling on of a barrow to be weighed. According to still another embodiment of the invention, the cross member is connected with the side beams at distance from the ends of the side beams and both pair of ends of the side beams are connected with cross beams, which permit a restricted twisting movement of the side beams around the longitudinal axis of the cross member. The cross beams can be arranged very low and thereby both of the ends of the walking planes can be mounted on low height above the foundation to also facilitate for an animal to get off or the rolling off of a barrow already weighed. In addition both ends of the scale are suitable for entering and thereby the positioning of the scale before weighing is facilitated. According to still an embodiment of the invention, the walking plane comprises several parallel ribs, which at their both ends rest on border members being firmly connected to the side beams on their sides facing each other. Such a walking plane easily follows the movement of the side beams as they adjust to the foundation. According to still a further embodiment of the invention, the ribs are reinforced by means of an extended support member, which distributes the load on one rib to adjacent ribs and which extends parallel with the side beams between the same and are arranged to support against the cross beam or the cross beams as well as the cross member when the walking plane is loaded. This support member makes possible light and thin ribs and contributes to make the entire scale structure light and easy to carry from one place to another. According to still a further embodiment of the invention, the side beams are hollow and include means for defining the weight of the load given from so called load cells being mounted between each foot and the corresponding side heam, the electric wires to the load cells being installed inside the side beans where they are covered from outside damage. The load cells can easily be arranged on or within the side beams. According to a further development of the invention, the side beams are hollow and the feet of each side beam are connected with the ends of a measuring bean being journalled in the side beam and supporting the same and the deformation of which being recorded by means of a strain gauge, the electric wires to the strain gauge being arranged inside the side beams. Such measuring beams with strain gauge are known per se from the US patent 2,899,191. By arranging the measuring beams according to the present invention inside the side beams, a very robust weighing device is obtained, and the scale can be dropped on to the foundation without being damaged. The electric wires to the strain gauges are also in this case protected from outside damage by being drawn within the side beams. The invenion will now be further described by means of three embodiments of the same with reference to the accompanied drawings, in which fig. 1 shows a view from above of a first embodiment of the scale having a walking plane mounted between two side beams, fig. 2 shows a sectional view according to dotted lines II-II in fig. 1, in which view the load cells for weighing of a load resting on the walking plane are visible, fig. 3 shows a sectional view according to dotted lines III-III in fig. 2 with the walking plane taken away to show the underlying scale frame structure, fig. 4 shows in a perspective view the scale resting on a plane foundation, the walking plane being indicated by means of point-broken lines, fig. 5 shows the scale of fig. 4 resting against an uneven foundation, fig. 6 shows a longitudinal section through one side beam in a second embodiment of the scale, according to which the load is weighed by means of a measuring beam arranged within each of the side beams, and fig. 7 shows a third embodiment of the scale according to which the walking plane extends between a cross member at one end of the scale and a cross beam at the other end of the scale. In fig. 1-5 two straight, parallel and hollow side beams of equal length are designated 11 and 12 and are connected with each other in the middle of themselves with an open profile bar 13 welded to each side beam 11 and 12. The profile bar is due to its open section relatively flexible for twisting around its longitudinal axis 14, and thereby the side beams 11, 12, which at each of their ends are provided with a foot 15, can be twisted with respect to each other in a plane being perpendicular to the axis 14 so that all four feet 15 will rest against a foundation 16 even if the foundation is uneven. The free ends of the side beams are connected by bars 17 and 18, which permit restricted twisting of the side beams around the axis 14, and consequently they are journalled with a corresponding play in the side beams. The walking plane 19 comprises several parallel ribs 20, which with their ends rest on border members 21 having an L-profile and -being welded to facing sides 22, 23 of the side beams. The ribs 20 are connected to the border members 21 by means of screws 24 or other guiding or fixing members which permit the ribs 20 to move with the side beams as they adjust to an uneven foundation. The ribs 20 are supported in the middle by a plane bar 25 mounted to support against the beam 13 and the bars 17 and 18. The ribs 20 are connected to the bar 25 by means of screws 41 or other fixing members so that the load on one rib 20 is distributed to adjacent ribs. The function of the bar 25 can also be provided by means of several bars extending through holes in the ribs and which at their ends are mounted to support, when loaded, against the edge of holes in the beam 13 and in the bars 17 and 18, whereby the height of the walking plane above the foundation 16 can be further reduced. The weight of the load is recorded by four so called load cells 26 known per se. The load cells 26 are mounted between each foot 15 and the side beams 11, 12. The electric wires 27 to the load cells 26 are drawn within the side beams 11, 12 and the beam 13 to an opening 28, from which the wires 27 are drawn to an apparatus 29, which in a way known per se adds the signals from the load cells and displays the total weight resting on the load cells. At the embodiment of the scale in fig. 6, the two load cells of each side beam are replaced by a measuring beam 30, which is journalled around journal pins 31, 32, being firmly connected to each side beam 11, 12. The ends of the measuring beams 30 are provided with legs 34, which extend out through openings 33 in each of the beams 11, 12, to rest against the foundation 16 by means of feet 35, which, as shown, can be constituted by wheels 36. Instead of a wheel, a conical body with rounded top can be arranged with its rounded top resting against the foundation. The load supported by each measuring beam gives a certain deformation of the measuring beam, which deformation is sensed by a strain gauge 37, which deliver an electric signal through lines 38. The lines 38 are connected through a bridge connection known per se to an apparatus, which calculates and displays the weight of the load that rests on the scale. At the embodiment according to fig. 7, the scale is made very simple in that the cross member 13A with its centre axis 14A has been mounted between one pair of ends of the side beams 11; 12, and a cross beam 17A has been mounted between the other pair of ends of the side beams. Also in the embodiments according to fig. 1-5 and 7, at least some of the feet 15 can be constituted by wheels or conical bodies if so is desired.

Claims: Claims 1. A weighing device comprising two essentially straight side beams (11, 12) of equal length and positioned in parallel at a distance from each other, said side beams supporting between themselves a walking plane (19) for the load to be weighed and being provided with a foot (15, 35, 36) at each of their ends to bear against a foundation (16), said feet being connected to a device (26, 27, 29, 30, 37, 38) for measuring the weight of the load, c h a r a c t e r i z e d i n that the side beams (11, 12) are movably mounted with respect to each other in essentially parallel planes going through the longitudinal axis of the side beams and being perpendicular to the foundation (16) so that, when putting the weighing device against an uneven foundation, all four feet (15, 35, 36) will bear against the foundation, the walking plane (19) being arranged to follow the movement of the side beams as they adjust to the foundation (16). 2. A weighing device according to claim 1, c h a r a c t e r i z e d i n that the side beams (11, 12) are connected by a cross member (13, 13A) which permits the side beams to twist with respect to each other around the longitudinal axis (14, 14A) of the cross member. 3. A weighing device according to claim 1 or 2, c h a r a c t e r i z e d i n that the cross member is constituted by an open profile bar (13, 13A), which is relatively flexible for twisting around its longitudinal axis (14, 14A) and which at its ends is firmly connected to the side beams (11, 12). 4. A weighing device according to claim 2 or 3, c h a r a c t e r i z e d i n that the cross member (13A) is connected with the side beams (11, 12) at one pair of ends of the side beams and that the other pair of ends of the side beams are connected with a cross beam (17A), which permits a restricted twisting movement of the side beams around the longitudinal axis (14A) of the cross member. 5. A weighing device according to claim 2 or 2, c h a r a c t e r i z e d i n that the cross member (13) is connected to the side beams (11, 12) at distance from the ends of the side beams and that both pair of ends of the side beams are connected with cross beams (17, 18), which permit a restricted twisting movement of the side beams around the longitudinal axis (14) of the cross member. 6. A weighing device according to any of the preceding claims, c ha r a c t e r i z e d i n that the walking plane (19) comprises several parallel ribs (20), which at their both ends rest on border members (21) being firmly connected to facing sides (22, 23) of the side beams (11, 12). 7. A weighing device according to claim 6, c h a r a c t e r i z e d i n that the ribs (20) are reinforced by means of an extended support member (25), which distributes the load on one rib (20) to adjacent ribs (20) and which extends parallel with the side beams between the same and are arranged to support against the cross beam (17A) or the cross beams (17, 18) as well as the cross member (13, 13A) when the walking plane (19) is loaded. 8. A weighing device according to any of the preceding claims, c h a r a c t e r i z e d i n that the side beams (11, 12) are hollow and that the device for measuring the weight of the load includes so called load cells -(26) known per se mounted between each foot (15) and the corresponding side beam (11, 12), the electric wires (27) to the load cells (26) being installed within the side beams (11, 12). 9. A weighing device according to any of the claims 1-7; c h a r a c t e r i z e d i n that the side beams (11, 12) are hollow and that the feet (35, 36) at each side beam is connected with the ends of a measuring beam (30), being journalled in and supporting the side beam, and that the deformation of said measuring beam (30) is recorded by a strain gauge (37), the electric wires (38) of said strain gauge being installed within the side beams.

Inventors: STENSTROEM LENNART, STENSTROEM, LENNART
Applicants: ALFA LAVAL AB, ALFA-LAVAL AB
Application year: 1983
Main classification: G01G17
IPC codes: G01G17