This invention relates to a support element with weight measurement for lifting platforms. Lifting platforms are used, among others, in automobile repair shops in order to raise vehicles for the purpose of repair and maintenance. The invention is described with reference to an automobile lifting platform.
Automobile lifting platforms are equipped with a wide variety of load-receiving elements for raising the vehicles. Most frequently, pivoting arms or longitudinally and/or laterally adjustable flat beams are used as load-receiving elements. The vehicles are usually raised at four points or locations. When supporting vehicles, it is important, on the one hand, to support the vehicles safely, i.e. at the correct locations on the underside of the vehicle. On the other hand, the maximum load capacity of the lifting platform or of a single carrying arm or support beam must not be exceeded.
In the field, vehicles are not always supported in accordance with the center of gravity of the vehicle—i.e. in a centered position—but frequently with the load distributed towards one side. Among others, this eccentric raising with uneven load distribution is caused by the circumstance that it improves the desired accessibility to the vehicle for certain operations, and that it makes it easier to perform maintenance and repair work without obstruction. This off-center raising involves sources of dangers that may lead to the impermissible loading of the lifting platform and the vehicle falling off the lifting platform.
The patent disclosure DE 29 37 582 A1 describes a lifting platform, specifically a dual-column lifting platform for automobiles where force measuring devices are arranged on the bearing elements whose output signals are fed into a downstream safety circuit that compares the signals with voltage values that are proportional to permissible loads and actuates an alarm and/or braking device if the permissible voltage values are exceeded. The system known from DE 29 37 582 A1 is a component of the lifting platform. For example, it can not be applied to lifting platforms that are already in operation. Also, this system is very complex and therefore also very expensive.
The utility model DE 93 12 286.1 describes a lifting platform with a plurality of carrying arms where, at the free ends of said carrying arms, removable support plates or similar devices are arranged on which sensors, switches, or similar devices detecting weight loads or one-sided loads are arranged that are connected to a display device, monitoring device, or a similar device. It is a disadvantage that a power supply is required, in the form of batteries or solar cells, or via radar and reflecting surfaces.
The patent disclosure U.S. Pat. No. 3,200,897 describes a hydraulic weight scale carried by trucks that is intended for mobile operation at different locations. Via a tilting platform, the truck can be driven onto the weight scale and the wheel load or, when several weight scales are used simultaneously, the axle load or the total weight can be measured during the loading process or during weight checks performed by the authorities. The weight scale consists of a cylinder housing with a strong bottom surface with which it rests on the ground. On the upper side, the cylinder housing has an opening. From this opening, a solid plunger piston protrudes vertically. Below the plunger piston, there is a hydraulic fluid that indicates a pressure commensurate with the wheel load resting on it. This weight scale has the disadvantage that the plunger piston is made of solid material. Specifically, it is not possible to arrange a passage or a threaded bore inside the plunger piston in which a vehicle support element could be housed whose height is adjustable, for example by means of a threaded spindle.
This invention addresses the problem of improving the handling and the safety of lifting platforms. It is intended to show the operator in an easily recognizable manner whether all support points of the vehicle rest with sufficient weight on the load-receiving element. In addition, it will be recognizable that neither an individual carrying arm and/or an individual support point of the load-receiving element is overloaded or that the maximum load capacity of the lifting platform itself has been exceeded. In particular, it will make it possible to retrofit this new safety standard even on older and already installed lifting platforms without requiring modifications of or changes on these lifting platforms.
Furthermore, the weight measurement will be possible without the supply of external energy, in particular without a power supply, so that a very inexpensive manufacture and retrofitting of lifting platforms becomes possible.
According to the invention, this is achieved by means of a support element with weight measurement for lifting platforms according to claim 1. Advantageous embodiments and advanced implementations are subject of the dependent claims.
The support element for lifting platforms according to the invention can be placed between a component of the load-receiving element of the lifting platform and the vehicle to be raised. On its underside with which it makes contact, the support element has at least one recess or groove in which a sealing transfer element sits. Preferably, the sealing transfer element protrudes partially from the support element. This ensures that the imposed weight force of the vehicle is transferred to the load-receiving element only by the transfer element. Above the transfer element, the recess or groove expands further, forming a pressure chamber filled with hydraulic fluid, said pressure chamber being connected to a pressure gauge that can be read from the outside. The weight force exerted by the vehicle on the load-receiving element via the support element and/or the transfer element generates a hydraulic pressure that is characteristic for the vehicle weight.
According to the invention, the recess or the groove as well as the sealing transfer element have an annular shape. The diameter of the annular transfer element should be designed as large as possible. This offers the advantage that, regardless of whether an identical load is applied centrally or eccentrically, approximately the same measured data will be displayed.
It is another advantage of the annular transfer element that components can be passed through the annular surface. For example, it is possible to provide an internally threaded hole in which a height-adjustable vehicle support is located.
In another embodiment, several individual cavities may be arranged in the support element, and may be interconnected by channels, for example, in such a way that even eccentric weight forces can be measured with accuracy.
In a suitable location—preferably on the side of the support element—a pressure gauge, e,g, a manometer, is installed. This manometer can be scaled to indicate either a pressure or a weight force in relation to the effective pressure surface.
Depending on the requirements, different pressure gauges may be connected to the support element. So-called mechanical pressure gauges like tube spring manometers, capsule spring manometers, plate spring manometers or other types of manometers may be connected to the bearing element. This has the advantage that no electric power supply is needed. It is also possible to connect so-called digital manometers, for example with a digital display showing the numeric value with the unit and/or text. Also, digital manometers are available that store measured data and are able to generate acoustic warning signals.
In another embodiment, instead of a pressure gauge, a sealing coupling may be installed, for example a snap coupling or a plug connector. Via this coupling or this connector, a pressure gauge may be connected—directly or indirectly via a connecting line—if a pressure or weight force measurement is required. This offers the advantage that only one pressure gauge is required for an individual lifting platform, and also that a single pressure gauge can be used for several lifting platforms.
This invention offers the advantage that the weight is measured in a very simple way at all support points on which a vehicle rests on the load-receiving element of a lifting platform. If a part of the load-receiving element is overloaded, or if no vehicle weight or too little vehicle weight rests on another part of the load-receiving element, a correction may be made and the vehicle can be supported in a secure position so that the aforementioned sources of dangers are eliminated. It can also be detected if a vehicle is loaded whose weight exceeds the maximum carrying capacity of the lifting platform.
It is yet another advantage that this support element can be retrofitted to older models of lifting platforms in a very simple way.
Below, the invention is described in detail and explained with reference to the embodiment shown in the drawing.
In an axial section,
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Number | Date | Country | Kind |
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10 2007 053 757 | Nov 2007 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE2008/001846 | 11/7/2008 | WO | 00 | 5/7/2010 |
Publishing Document | Publishing Date | Country | Kind |
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WO2009/062477 | 5/22/2009 | WO | A |
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29 37 582 | Apr 1981 | DE |
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Entry |
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International Search Report for corresponding International Application No. PCT/DE2008/001846 mailed Jun. 5, 2009. |
Form PCT/ISA/237 for International Application No. PCT/DE2008/001846 dated Jun. 5, 2009. |
Number | Date | Country | |
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20100276212 A1 | Nov 2010 | US |