WO1989008568A1

WO1989008568A1 - A mobile weighing system

Info

Publication number: WO1989008568A1
Application number: PCT/DK1989/000054
Authority: WO
Inventors: Henning Moeller Nielsen
Original assignee: Henning Moeller Nielsen
Priority date: 1988-03-11
Filing date: 1989-03-13
Publication date: 1989-09-21
Also published as: AU3442589A; DK134088D0

Abstract

A mobile weighing system, in particular a mobile weighing system on a lorry for registration of goods being loaded or unloaded, comprising a number of weighing cells (20) with belonging registration equipment. The weighing cells (20) being mounted between a chassis frame (10) for a goods receptacle or a cargo surface and a separate carrying system (8) with adjustable supporting legs (4), because in connection with the weighing cells (20) are arranged engagement means being adapted to establish an active weighing engagement between the separate carrying system (8) and the chassis frame (10). The engagement means consist of locking cylinders (12, 74) which at one end comprises a lifting mechanism (78) and which at the opposite end is connected to the carrying system (8). The locking cylinders (12, 74) in which the weighing cells (20) are built in comprises connection means (82, 84, 90, 92) being such adapted that the carrying system (8) partly may be supported hanging under the chassis frame (10) by means of the locking cylinders (12, 74) and partly may consist a mainly horizontal support surface for the locking cylinders (12, 74), because the lifting mechanism (78) in the situation last mentioned being adapted to be activated in order to establish active weighing engagement, where the chassis frame (10) is completely supported by the weighing cells (20) which in the situation first mentioned are not loaded at all.

Description

A MOBILE WEIGHING SYSTEM.

The present invention relates to a mobile weighing system, i particular a mobile weighing system on a lorry for registrat ion of goods being loaded or onloaded and of the type mention ed in the introductory part of claim 1.

Mobile weighing systems of this type have been known for man years; however with a limited success. Especially it has bee problematic to obtain the authorities approval of such weigh ing systems because so far the known mobile weighing system have been to unstable and with that to inaccurate. Furthermor the systems in question have been very expensive which may b put down to a very complicated mechanical construction of th known weighing systems of the type in question which only i very small scale have been used in certain branches of trade e.g. in distribution of flour and feedstuffs.

A common feature by most of the known mobile weighing system and in a way also by the invention is determined of the avail able types of powerful weighing cells which requires an ap proximate vertical, axial load which in practice is easil obtained by in the weighing situation to make use of a mainl horizontal weighing plane which by the mobile weighing system known so far have comprised a powerful carrying stand wit hydraulic telescope supporting legs which are used to estab lish said horizontal carrying plane or weighing plane. The s far most simple mobile weighing system makes use of weighin cells being built in directly in the top end of hydrailic cy linders of said supporting legs; however, due to uncontroll able bending tensions in the supporting legs in case of uneve terrain this solution has to be given up. Attempts have als been made to neutralize transverse loads of the supportin legs by rotation of these during the weighing operation. Th latest known weighing system of the type in question make us of weighing cells which are interconnected between two carry ing chassisses for the goods receptacle or the platform, whic weighing system gives an acceptable weighing result; but whic weighing system in practice is not realistic due to a ver complicated and expensive mechanical construction. Anothe disadvantage by the type of weighing system last mentioned i that this system because of the permanent load of the weighin cells so far has not obtained approval by the authorities

The invention has for its purpose to provide a mobile weighin system, in particular a mobile weighing system of the typ introductory mentioned and by means of which the above mentio ned disanvantages in a simple manner may be obviated.

According to the invention the mobile weighing system is cha racterized in that said engagement means consist of lockin cylinders which at one end comprises a lifting mechanism an which at the opposite end being connected with said carryin system in such a manner that the carrying system partly may b hanging supported by said separate carrying means or by sai chassis frame and partly may provide an approximate horizonta carrying surface for the locking cylinders, said- liftin mechanism being adapted - in the situation last mentioned - t be activated in order to establish said active weighing enga gement, and that the weighing cells are placed inside in th locking cylinder. Hereby may in a very simple marine be estab lished a powerful and stable connection between said carryin means or said chassis frame - which normally consists of th wheel supported chassis frame of the lorry - and the separat carrying system which as usually may be supported by hydrauli supporting legs at each side of the lorry. During driving th carrying system is suspended under the chassis frame of th lorry by means of said locking cylinders which in the weighin situation, i.e. with the driving wheels lifted up and wi horizontal carrying system, by means of the said built lifting mechanism may deactivate the carrying engagement be tween the carrying system and the carrying means or the chas sis frame and establishing the weighing engagement betwe them by couple in the weighing cells being. built in in t locking cylinders. Preferably the direct weighing engageme via the weighing cells is only established momentarily befo unloading of goods and after the onloading of goods, respecti¬ vely, by activation of said lifting mechanism.

Appropriately consist the locking cylinders of two concentric cylinder parts in the form of a lower cylinder part inside which the weighing cell is connected to a bottom plate member being adapted to be secured to said separate carrying system and an upper cylinder part in which said lifting mechanism is built in and being adapted to be secured to said separate car¬ rying means or to said chassis frame, and in that said engage- ment menas consists of upper radial edge portions and lower radial edge portions, respectively, of said cylinder parts.

The mobile weighing system according to the invention is fur¬ thermore characterized in that an upper active engagement part of the weighing cell is adapted to engage with a lowermost part of said lifting mechanism which for that purpose com¬ prises a particular thrust bearing being adapted to during said active weighing engagement to counteract transverse force influences of the weiging cell, when said engagement means in the weighing situation is inactive.

The invention is described in more detail reference being made to the accompanying drawing, in which:-

Fig. 1 shows a tank lorry with a mobile weighing system accor¬ ding to the invention,

Fig. 2 is a partial view of a lorry with a mobile weighing system according to the.

Fig. 3 is a side view - partly in section - of an embodiment of a locking cylinder of a mobile weighing system according to the invention.

Fig. 4 is a side view - partly in section - of an embodiment of a locking cylinder or locking house of a mobile weighing system according to the invention - shown in driving position, and Fig. 5 a side view - partly in section - of the locking cy linder shown in Fig. 4 in the weighing situation, i.e. wit weighing cell coupled in and inactive carrying engagemen between the parts of the locking cylinder.

The tank lorry 2 shown in Fig. 1 is equipped with a mobil weighing system, why the tank lorry 2 is provided with hydra lie supporting legs 3 so that the chassis frame of the tan lorry may be placed approximately horizontal in relation to a inclined fundation 6.

As shown in Fig. 2 the supporting legs 4 furthermore may b arranged telescopical in relation to a carrying system 8 whic is monted in a distance under the chassis frame 10 of the lor ry in as much as between the carrying system 8 and the chassi frame 10 is interconnected a locking cylinder 12 which upward is secured by means of bolts under the customary chassis 1 of the lorry, while the locking cylinder 12 downwards is secu red to the carrying system 8, i.e. that this including th supporting legs 4 - in the driving position shown in Fig. 2 is hanging supported by means of the locking cylinders 12 o which normally being used four under the chassis frame 10.

The locking cylinder 12 is shown in more detail in Fig. 3 an consists of a cylindrical tubular mantle 14 which at the bot tom is secured by welding to a foot ring member 16 cooperatin with a connection plate member 18 which is adapted to be se cured on top of a tranverse beam of the carrying system (Fig. 2) and which inside the tubular mantle 14 forms a car rying surface for a weighing cell 20 which is also secured t said transverse beams of the carrying system 8 - by means o not shown bolts - streching through free holes 22 in the con nection plate member 18 which in this way is simultanously se cured to the carrying system 8.

In principle, the foot ring member 16 is loosely supported o the connection plate member 18 which for that purpose alon its periphery has a plane edge zone 24 which inwardly is lead ing into an inclined, ringshaped guiding surface 26. The foo ring member 16 is provided with a corresponding plane edge zo ne and an inclined guiding surface inwardly, i.e. that th foot ring member 16 and the connection plate member 18 are mu tually self-centering.

The connection plate member 18 is around a lower end portio 28 of the weighing cell 20 provided with a carrying surface 3 having an outstanding, surrounding edge portion 32 which a the underside is provided with a covering 34, e.g. of har rubber, because the outstanding edge portion 32 of the car rying flange member 30 serves to engage with an edge portio 35 turning upwards of an interior ring surface 37 of the foo ring member 16.

Upwards the tubular mantle 14 of the locking cylinder 12 i connected to a top section 38 by means of a threaded sleeve 4 being secured to the top section by welding. The top section 38 has an upper connection plate member 42 which is also se¬ cured by welding to the top section 38 and which is adapted to be secured by means of bolts to the underside of the chassis frame 10 of the lorry (Fig. 2). The connection plate member 42 is provided with a central cylindrical piston housing 44 in which an upper part 46 of a cylindrical piston 48 is displace- ably arranged as furthermore the piston 48 is guided against a cylindrical interior wall 50 of the top section 38, i.e. that the piston 46,48 consist of two parts which after all are firmly interconnected. Furthermore, the piston part 48 coope¬ rates by means of an external guiding surface 53 with a loc¬ king ring member 52 being secured in the cylindrical interior wall 50 of the top section 38.

Between the pistion part 48 and a circuler bearing plate mem¬ ber 56 of steel is positioned a plastic plate member 58 which is made from a artificial resin material having a very little coeffecicient of friction, e.g. Delrin, and which is provided with a large number of through-going holes 60 in which is loo- sely positioned a corresponding number of steel balls 62 each having a diameter slightly larger than the thickness of th plastic plate member 58. This is along its periphery provide with a bended out, springy guiding lip 64 which is guide against the interior wall 50 of the top section 38.

The plastic ball plate member 58 forms an almost "floating'' connection between the piston part 48 and the bearing plat member 56. The later is lossely arranged in the top section 3 in as much as the bearing plate member 56 in external rin recesses is provided with sliding rings 66 made from a mate rial having little coefficient of friction. The bearing plat member 56 is in the underside provided with a central, cylin drical recess 68 in which an upper end portion 70 of the acti ve part of the weighing cell 20 is arranged in such a manne that the bearing plate member 56 may allow to tilt very sligh tly in relation to the upper end portion 70 the topside o which is spherical in as much as the end portion 70 further more is held in place in the recess 68 by means of an 0-rin member 72.

In Fig. 3 the locking cylinder 12 is shown in a situation cor responding to that onloading or loading is taken place, i.e with lowered supporting legs 4 so that the locking cylinder 1 is supported on the carrying system 8 and the chassis fram 10, i.e. in such a manner that also the goods recptacle i supported on the carrying system 8 via the locking cylinde 12. In this situation the weighing cell 20 is loaded not wort mentioning.

When weighing is wanted the lifting mechanism built in in th top section 38 is activated and hydraulic fluid (200 bar) i let into the piston housing 44 on top of the pistion part 46 This is herby displaced downwards until engagement is obtaine between the other piston part 48 and the locking ring membe 52. Hereby the load is tranferred to the weighing cell 20 be cause the foot ring member 16 of the locking cylinder 12 i simultaneously lifted fre of the connection plate member 18 i.e. that the whole approximate vertical load may be registe red by means of the registration equipment connected with th weighing cell 20. After the weighing the hydraulic pressure i again released from the piston housing 44 and the situation shown in Fig. 3 is reetablished.

In the driving situation the supporting legs 4 of the carrying system are lifted free of the ground and the carrying system 8 is hanging suspended of the wheel-supported chassis frame 10 via the locking cylinders 12 because now carrying engagement is established between the foot ring member 16 and the car¬ rying flange 30, i.e. without that the weighing cells 20 being loaded .

It should be mentioned that the lifting movement of the lift¬ ing mechanism built in in the top section 38 is rather small - only some 4 mm. Therefore the top side of the piston part 46 is formed with the shown concave shape so that room is maded for some extra hydraulic fluid which only in the teory is completely incompressible, i.e. that the relative small lift¬ ing movement is more easier to control accurately.

Alternatively the weighing cell 20 may be loosely arranged in the locking cylinder in as much as the weighing cell 20 also at the bottom may be shaped with a spherical bearing pin being hold in place by means of an 0-ring member. Upwards the bear¬ ing plate member 56 may be directly connected with the piston part 46 by means of an intermediate section which substitutes the piston part 48 and the steel ball filled piasic plate por¬ tion 58, i.e. that the weighing cell at opposite ends are pro¬ vided with central, spherical pin portions. In stead of the "floating¹' connection in the top section 38 of the locking housing the carrying system or maybe only transverse portions thereof may be directly connected with the chassis frame 10 by means of suiteable rubber straps.

A simplified and preferred embodiment of a locking cylinder 74 to the mobile weighing system according to the invention is shown in Figs. 4 and 5 in "the driving position" and "weighing position", respectively. The locking cylinder 74 which as a unit is adapted to be secured between the chassis frame 10 of the tank lorry and the separate carrying system 8 (Fig. 2) consists of two concentrial cylinder portions, namely a lower cylindrical tubular mantle 76 and an upper cylindrical lifting mechanism 78. The tubular mantle 76 is downwards connected by welding to a bottom plate member 80 to which also the base portion of the weighing cell 20 is secured as the bottom plate member 80 is adapted to be secured to the carrying system (Fig. 2). The tubular mantle 76 is upwards connected by weld¬ ing with a ring-shaped carrying flange 82 which at the inner- side is provided with an upper carrying surface 84 and which at the outside is provided with a screw threading 86 for a ring-shaped connection section 88 having an upper edge portion 90 streching inwardly above a lower radially outstanding con¬ nection portion 92 of the lifting mechanism 78.

The connection portion 92 is at the top side provided with a covering 94, e.g. of hard rubber, being adapted to cooperate with the edge portion 90 of the connection section 88, while the underside of the connection portion 92 has a shape which fits together with the carrying surface 84 of the carrying flange 82, i.e. that the connection portion 92 is adapted to as well to be supported directly in a self-centering manner on the carrying surface 85 in a "before weighing situation" whic moreover corresponds to the situation shown in Fig. 3 of th locking cylinder 12, where the chassis frame 10 with the sup porting wheels lifted free from the ground are supported on the carrying system 8 via the locking cylinders 12 or 74, a to form a support for the complete carrying system 8 by carry ing engagement between the topside of the connection portio 92 and the edge portion 90 of the connection section 8 (Fig. 4 - "driving position").

The lifting mechanism 78 consist - as shown - by a tube-shape housing 96 which downwards is provided with the outstandin connection portion 92 and which upwards is connected with top section 98 which parly is adapted to be secured under th chassis frame 10 of the lorry (Fig. 2) and partly is provide with an internal, cylindrical bore 100 in which is arranged a hydraulic piston 102 which with its upper hollow side is adapted to be influenced by hydraulic fluid which at a relati- ve high pressure (200 bar) is let into the cylinder bore 100. The piston 102 cooperates with a spring plate member 104 which is supported of an upper bearing plate member 106 which again is loosely suspended on a stop ring 108 being secured in a ring-shaped recess in the interior wall of the housing 96. In Figs. 4 and 5 the bearing plate member 106 shown in its lower position, i.e. supported on the stop ring 108, however in the above-mentioned "before weighing situation" the bearing plate member 106 may take in a position where it is almost lifted entirely free from the stop ring 108. Between the pis- ton 102 and the plate spring member 104 is shown an adjustment plate member 110 the purpose of which is to compensate for possible internal clearancein the lifting mechanism 78.

The weighing cell 20 is by means of an upper bearing pin 70 having spherical top end arranged in a recess 68 in a lower bearing plate member 112, i.e quite similar to that of Fig. 3. And between the bearing plate members 106 ans 112 is position¬ ed a particular thrust bearing 114 consisting of a bearing ring 116 which is almost filled out by a large number of steel balls 118 and which moreover is guided against the interior wall of the housing 96. Finally the two cylinder portions, the lifting mechanism 78 and the connection section 88, of the locking cylinder 74 are interconnected by means of an external flexible mantle 120 which is held in place on the respective parts by means of surrounding clamps 122.

Claims

Claims :

1. A mobile weighing system, in particular a mobile weighing system on a lorry for registration of goods being loaded or onloaded, comprising a number of weighing cells with belonging registration equipment, which weighing cells being mounted between separate carrying means or a common chassis frame for a goods receptacle or a cargo surface and a separate carrying system with adjustable supporting legs, in connection with said weighing cells being arranged engagement means being adapted to establish an active weighing engagement between the separate carrying system and said separate carrying means or said chassis frame, c h a r a c t e r i z e d in that said engagement means consist of locking cylinders which at one end comprises a lifting mechanism and which at the opposite end being connected with said carrying system in such a manner that the carrying system partly may be hanging supported by said separate carrying means or by said chassis frame and partly may provide an approximate horizontal carrying surface for the locking cylinders, said lifting mechanism being adapted - in the situation last mentioned - to be activated in order to establish said active weighing engagement, and tha the weighing cells are placed inside in the locking cylinder.

2. A mobile weighing system according to claim 1, c h a r a c t e r i z e d in that said locking cylinders consist of tw concentric cylinder parts in the form of a lower cylinder par inside which the weighing cell is connected to a bottom plat member being adapted to be secured to said separate carryin system and an upper cylinder part in which said lifting mecha nism is built in and being adapted to be secured to said sepa rate carrying means or to said chassis frame, and in that sai engagement menas consists of upper radial edge portions an lower radial edge portions, respectively, of said cylinde parts.

3. A mobile weighing system according to claim 2, c h a r a t e r i z e d in that an upper active engagement part of th weighing cell is adapted to engage with a lowermost part o said lifting mechanism which for that purpose comprises a particular thrust bearing being adapted to during said active weighing engagement to counteract transverse force influences of the weiging cell when said engagement means in the weighing situation is inactive.