Patent Application
20100187022
The present invention relates generally to industrial scales and, more particularly, it relates to industrial pallets used for weighing loads.
Commercial floor scales are used throughout industry to weigh raw materials, finished goods, shipments and other items involved in commerce. Existing commercial floor scales utilize a relatively standard construction consisting of a metal weighing platform, up to four load cells, a junction box, and a display unit. The current generation of floor scales lacks several advantages. For example, there are no lightweight (under 25 kg), portable, high-capacity (over 500 kg) floor scales. No existing floor scales utilize a pallet or similar construction as its weighing platform. Existing floor scales employ shear-beam activated load cells without mechanisms to protect the load cell from damage during transport or from harsh industrial environments. There are also no floor scales which utilize five or more load cells to determine accurately the weight of objects.
Floor scales are used in commercial settings for the weighing of a wide variety of objects. Due to their heavy-duty construction (most weigh over 100 kg), such scales are not readily movable within the factory floor and are too cumbersome to be transported for use in multiple locations. In addition, such scales rely on four shear-beam activated load cells which require a shear plate to transfer the force of the load from the platform. Such design limits the range of materials which can be used in construction of the platform. Existing shop floor scales also incur high repair costs due to a common design element in which electrical cables are integral to the load cell. When, as is a common issue, the cable fails, the entire load cell/cable assembly must be replaced by a skilled technician.
Accordingly, there is a need for an industrial scale that addresses these shortcomings by eliminating the shear beam construction requirement and utilizing new load cell designs and platform configurations to reduce the scale's weight, improve its portability and ease maintenance.
It is an object of the present invention to obviate or mitigate at least one disadvantage of previous floor scales. In a first aspect, the present invention provides an industrial pallet. The industrial pallet includes a platform free of a shear plate assembly, load sensors and a display unit. The platform supports a load, and the load sensors support the platform over a surface. Each of the load sensors include a load cell having a pressure member coupled to the surface and coupled to a strain gauge for providing weight data in response to a downward force of the load. The display unit is in data communication with the load sensors for displaying a weight corresponding to the load when the protection means is in the weighing position. The display unit can include one of an LCD display and an LED display, and be in data communication with at least one computer having a Central Processing Unit (CPU) and a monitor. The display unit can be the monitor of the computer. In an embodiment of the present aspect, each of the load sensors further includes protection means for supporting the platform on the surface and preventing the downward force from being relayed to the pressure member in a protective position. The protection means couples the pressure member to the surface in a weighing position. The protection means can include an extension foot for coupling the pressure member to the surface in the weighing position, and spacing means for supporting the platform on the surface in the protective position.
In one particular embodiment, the spacing means includes support members extending from an undersurface of the platform towards the surface beyond the pressure member by a distance of X in the protective position, and the extension foot is insertable between the pressure member and the surface in the weighing position, the extension foot having a thickness of Y greater than X. The extension foot is connected to a resilient support arm pivotably connected to a body of the load sensor. In another particular embodiment, the extension foot includes a cup-shaped spacer having a base and an integral sidewall extending from the horizontal base and terminating in a rim. The cup-shaped spacer substantially houses the load cell while supporting the platform on the surface in the protective position. The cup-shaped spacer is invertable in the weighing position where the base engages the pressure member and the rim rests on the surface. In yet another particular embodiment, the spacing means includes an annular wall surrounding the load cell and extending downwardly towards the ground beyond the pressure member, and the extension foot is in threaded engagement with the pressure member. The extension foot extends beyond the annular wall for contacting the surface in the weighing position, and is retractable to be suspended within the annular wall in the protective position.
In another embodiment of the present aspect, there is provided a junction box for receiving the weight data of each load sensor, and for providing aggregate weight data to the display unit. In this embodiment, the junction box includes standard input jacks for releasably receiving first complementary plugs connected to each of the load sensors, and a standard output jack for releasably receiving a second complementary plug connected to the display unit. The junction box is permanently sealed for securing the standard input jacks and the standard output jack. The junction box can include a summing board having a signal bus connected to the standard output jack, where each standard input jack has a set of wires connected in parallel to the signal bus. The standard input jacks and the standard output jack includes one of an RJ-11 and an RJ-45 jack, and the first complementary plugs and the second complementary plug includes one of an RJ-11 and an RJ-45 plug, respectively.
In yet a further embodiment of the present aspect, the platform includes at least two foldable sections foldable with respect to each another about at least one folding axis, where the at least two foldable sections are foldable between a planar position and a folded position. Locking means are provided for releasably locking the pallet in the folded position. The platform can be constructed of a thermoplastic material to include at least one hinge-forming groove between adjacent foldable sections for providing a pliable hinge connection to allow the two adjacent foldable sections to fold between the planar position and the folded position. In an alternate embodiment, the platform includes a central section adjacent to two end sections foldable towards each other and relative to the central section at corresponding folding axis′. Each of the two end sections are foldable up to a substantially 90-degree angle relative to the central section for housing the load sensors. The pallet can include a handle connected to a first end of the platform for lifting the first end to an inclined position, and a plurality of wheels connected to a second end of the platform opposite the first end for engaging the surface when the platform is lifted into the inclined position.
In a second aspect, the present invention provides a load sensor mountable to an undersurface of a platform. The load sensor includes a load cell and protection means. The load cell has a pressure member coupled to a surface and physically connected to a strain gauge for providing weight data in response to a force applied to the platform. The protection means supports the platform and inhibits the downward force from being coupled to the load cell in a protective position, the protection means couples the pressure member to the surface in a weighing position. In one embodiment of the present aspect, the protection means includes an extension foot for coupling the pressure member to the surface in the weighing position, and spacing means for supporting the platform on the surface in the protective position. In one particular embodiment, the spacing means can include support members surrounding the load cell for supporting the platform on the surface, where the support members extend from the undersurface towards the surface beyond the pressure member by a distance of X in the protective position, and the extension foot is insertable between the pressure member and the surface in the weighing position. The extension foot has a thickness of Y greater than X. In this embodiment, the extension foot is connected to a resilient support arm pivotably connected to a body of the load sensor.
In another particular embodiment, the extension foot includes a cup-shaped spacer having a base and an integral sidewall extending from the horizontal base and terminating in a rim. The cup-shaped spacer substantially houses the load cell while supporting the platform on the surface in the protective position. The cup-shaped spacer is invertable in the weighing position where the base engages the pressure member and the rim rests on the surface. In yet another particular embodiment, the spacing means includes an annular wall surrounding the load cell, which extends downwardly towards the ground beyond the pressure member, and the extension foot is in threaded engagement with the pressure member. The extension foot extends beyond the annular wall for contacting the surface in the weighing position, and is retractable to be suspended within the annular wall in the protective position.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:
The following description and accompanying drawings are presented to enable any person skilled in the art to make use of the invention and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. The appended claims, properly construed, form the only limitation upon the scope of the invention.
The present invention is described with the environment of industrial pallets in mind; however, it is to be understood that the embodiments of the invention described and illustrated herein are applicable to a broad class of apparatus including platforms which can be converted into a scale, and the presently described embodiments are not limited to the application to pallets.
It is to be understood that in this document, the term “load sensor” is used in reference to a load cell including its housing and/or all the elements that are associated therewith, such as a mechanical relay or an electrical connection such as a jack. It is also to be understood that terms such as “a housed load cell” and “a partially housed load cell” refer to the housing or partial housing of the load cell.
The embodiments of the present invention are directed to an industrial pallet/scale including a shear beam free and/or shear plate-free platform for supporting a load, having at least three load sensors positioned between and in mechanical communication with the platform and ground. The use of a platform free of a sheer beam and/or shear plate significantly reduces the weight of the metal that is needed to support the shear plates of the platform itself, relative to existing floor scales. Each load sensor provides weight data responsive to a downward force relayed from the platform. A display unit in electrical communication with the at least three load cells displays text in response to the weight data of all the load cells. The industrial pallet/scale optionally includes load sensors having protection means for protecting the load cells. The protection means functions as a support for the platform, which bears the load of the platform in a protective position. The protection means prevents a pressure member of the load cell from contacting the ground. In a weighing position, the pressure member is coupled directly, or thru a extension foot to the ground, such that the load cell of the load sensor bears the load of the platform.
The following descriptions of the different compression type load sensor embodiments are intended for use with any sheer beam and/or shear plate free platform. One type of compression type load sensor is described in use with the pallet-scale embodiments by example only, as those skilled in the art will appreciate that the other compression load sensor embodiments can be used with equal effectiveness. The compression type load sensors described herein are simply referred to as load sensors.
In
Loads cells come in different shapes and forms. One example configuration is shown in top and bottom perspective views in
The extension foot 101 of the load sensor is in physical communication with the arm 201 in order to transfer any force applied to the extension foot 101 to the arm 201. The load cell 200 is electrically connected, usually via an electrical cable 202, to the jack 102 of the load sensor 100 for outputting the signal of the load cell 200.
Referring to
Placing a load on top of the platform 301 would apply a downward force on the pallet corresponding to the weight of the load. This downward force is transmitted to the pallet's legs 302 and, therefore, to the load sensors 100 such that the sum of the individual forces applied to all nine load sensors 100 corresponds to the weight of the load. Different load sensors 100 with different load capacities could be used to provide for different ranges of capacity ratings for the pallet-scales 300. While the example pallet described above includes 9 load sensors, any number of load sensors can be used, provided the pallet is suitably supported when loaded with objects or materials.
The mounting of the load sensors on the legs 302 can be achieved in any way well known by those skilled in the art. As will be discussed later, the load sensors can be permanently fixed to the legs 302 or releasably attached to the legs 302. The load sensors 100 should be mounted in a manner that ensures that all their extension feet are in contact with a level ground. The load sensors and display are designed in such a fashion as to provide accurate readings on uneven surfaces where one or more load sensors may not be in contact with a ground. Since the weight can be distributed to fewer load sensors, the magnitude of deflection of the strain gauge of those load sensors in contact with the ground would be greater than if all the load sensors shared the load. Hence the aggregate data signal will still correspond to the actual weight of the load.
In another embodiment of the invention, which is shown in
Likewise, the load sensors 100 can be mounted to the undersurface of the platform 401 in any way well known by those skilled in the art, so long as when they are supporting the platform 401 over the ground, all of the extension feet 101 are in contact with a level ground surface. As before, the load sensors and display unit are designed to provide accurate readings on uneven ground surfaces.
Although
As discussed above, the load cell 200 is electrically connected to the jacks 102 of the load sensors 100 for outputting the weight data signal of the load cells 200. In the present embodiment, each load sensor 100 outputs its weight data to a junction box 303. An example junction box is shown in
An example display unit is shown in
The jacks of the load sensors 102, the junction box 501,502, and the display unit 602 could be any type of jacks, which in combination with cables terminated with the corresponding plugs, would allow the load sensors 100 to be electrically connected to the junction box 303, and the junction box 303 to be electrically connected to the display unit 304. Connecting the load sensors 100 to the junction box 303 allows the junction box 303 to receive weight data signals from each load cell 200; similarly, connecting the junction box 303 to the display unit 304 allows the display unit 304 to receive the aggregate load signal for processing. Two example jacks are the 6P4C (commonly RJ-11) and 8P8C (commonly RJ-45) jacks, which would allow the load sensors, the junction box and the display unit to be connected by respective 6P4C and 8P8C plug terminated cables, such as standard telephone and LAN cables, for example. Of course, any other standard or customized complementary connectors can be used.
According to an alternate embodiment, the display unit 304 could be in a remote physical location and connected wirelessly to the junction box 303 by using either wireless components that plug into such jacks, or wireless components instead of jacks. Wireless technology such as radio frequency (RF), Blue Tooth or WiFi can be used for communicating the data wirelessly. In the embodiment where the jack is replaced by wireless communication circuits, the load sensor can house the necessary circuits for converting the weight data signal from the load cell into a corresponding wireless signal. For example, an analog to digital converter (ADC) converts the analog weight data signal into digital form, and then a transceiver or transmitter transforms the digital data signal into a wireless signal. In the embodiment where a wireless component is plugged into the jack, the wireless component can be a module housing the aforementioned ADC and transceiver, as well as a suitably shaped plug complementary to the jack. Also, the display unit 304 can be fitted with a USB interface/port (not shown) for sending the weight of the load to a computer or a computer network for integration into an inventory system or a shipping and receiving system. Further, the weight of the load can be sent wirelessly (or otherwise) directly from the junction box to a computer, a computer network, or a portable device; therefore, eliminating the need for a separate display unit. In the latter embodiment, the weight of the load could be displayed on a computer monitor or the portable device.
The embodiments of the present invention could as well be practiced without the use of a junction box, in which case the display unit would include (1) a plurality of input jacks for connecting the display unit directly to the load sensors for allowing the display unit to receive the weight data of each individual load sensor, (2) a summing board as the one described above in connection with the junction box, for integrating the signals received from each of the load sensors, and (3) display circuitry to process the integrated signal and display a value for the weight of the load.
Due to the industrial environments in which these pallet-scales 300,400 are used, it is desirable that the load sensors 100 are protected from rough handling. For example, the tines of a fork lift can accidentally strike the load sensors attached to the legs of pallet 300. One simple form of protecting the load sensors 100 is to adapt them to be detachably mountable to the pallets—that is, to the legs 302 of a nestable platform 301 or to the undersurface of a stackable platform 401—so that the load sensors 100 can be detached from the pallets and safely stored when the pallet is not in use as a scale. Adapting the load sensors 100 to be detachably mountable to the platform 301,401 could be done by using any suitable detachable mounting means, such as screws and nuts where the user can secure the load sensors to the platform when the scale functionality is desired, and unscrew and safely store them separately when no further scale functionality is required, ie. During transport. Another technique for detachably mounting the load sensors is to thread a portion of the body of load sensor 100 such that it mates with a corresponding threaded hole or aperture in the bottom of the platform.
As mentioned above, load cells come in different shapes and forms and, needless to say, different forms of protection means are used to protect these load cells. The above-discussed protection means, for example, is suitable for protecting load cells housed within the load sensor 100 of
As will be discussed in greater detail below, the following load sensor embodiments can be permanently attached to the platform of the previously described pallets or to other suitable weighing platforms. The protection means of these alternate load sensors include spacing means for spacing the load cell from the ground to prevent any force from being applied to the load arm of the load cell when the pallet is not being used as a scale, and extension feet to couple the load cell to the ground when the pallet is being used as a scale for relaying a force to the load arm of the load cell.
The load sensor 700 also includes a extension foot 706 dimensioned to have a thickness Y, which is larger than distance X, the extension foot being pivotably connected to the load sensor 700 by a flexible arm, so that it can swing between a first position (
The sensor of
The spacer 1001 includes a recess (not shown) to receive the arm 703 of the load cell 701 in the cupping position to minimize interference with load cell 701. Correspondingly, the groove 1201 would be shaped as shown in FIG. 12—that is, arcuately, or substantially circularly shaped—to complement the recessed part of spacer 1001. In an alternative embodiment, the size of spacer 1001 is enlarged to encompass the entirety of arm 703 of the load cell 700. For the latter, no recess is required in 1001, and the groove would be circularly shaped to receive the complete and enlarged rim of spacer 1001.
Although the cup-shaped spacer 1001 is shown as a frustum of a right circular cone in
Load sensor 1301 includes a spacer, such as annular wall 1304 that acts as a leg to support the pallet 1308 over the ground when the pallet 1308 is not being used as a scale, as shown in
The extension foot 1305 is rotatable between a first position as shown in
The flexible beam 1302 has a strain gauge 1303 connected to it such that when the extension foot 1305 is supporting the pallet 1308 over the ground, the flexible beam 1302 flexes upwardly to deform the strain gauge 1303. The strain gauge 1303 converts the deformation into an electrical signal, which is then used to calculate the downward force applied by the load.
All of the previously discussed load sensors and their associated protection means can be used with the pallets of
Turning now to
In
As shown in
It is to be generally understood that, in this document, where the invention is described in a device-oriented fashion, the description relates to the device in its operational state—meaning, the device is in an orientation that allows each of the elements associated with the description to perform its implicit function.
Further, in the drawings, it is to be understood that standard components or features that are within the purview of an artisan of ordinary skill, and do not contribute to the understanding of the various embodiments of the invention may be omitted from the drawings to enhance clarity.
The above-described embodiments of the invention are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2590185 | May 2007 | CA | national |
| 2590467 | May 2007 | CA | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/CA2008/001023 | 5/29/2008 | WO | 00 | 11/27/2009 |
