Patent Application
20140083209
The present invention generally relates to force sensors, and more particularly relates to a mechanically coupled force sensor implemented on a relatively flexible platform assembly structure.
Force sensors are used in myriad systems and environments. End-users of force sensors are demanding greater performance and smaller packaging. In particular, many end-users are demanding force sensors with a Total Error Band of around 1% over a specified temperature range. In addition to increased performance, sensor cost is also a big driver. The markets of some end-users exhibit relatively stringent cost pressures. Historically, force sensor suppliers have addressed these demands via two separate options. One option is to provide an uncompensated/unamplified force sensor, which can be manufactured into a relatively small package. The second option is to provide an amplified/compensated force sensor. These latter sensors, however, are manufactured into relatively large packages. One reason for this is that a mechanically-coupled, amplified solution that can be practically and economically calibrated has not yet been developed.
Hence, there is a need for a force sensor system that exhibits relatively good performance in relatively small packaging, and that can be practically and economically calibrated. The present invention addresses at least these needs.
In one embodiment, a force sensor system includes a substrate, a cover, a sensor, and a spherical force transfer element. The cover is coupled to the substrate, and has an inner surface, an outer surface, and an opening extending between the inner and outer surfaces. A wall structure extends from the inner surface that defines a sensor cavity between the inner surface and the substrate. The sensor is mounted on the substrate and is disposed within the sensor cavity. The sensor is configured to generate a sensor signal representative of a force supplied to the sensor. The spherical force transfer element is disposed partially within the sensor cavity and is movable relative to the cover. The spherical force transfer element extends from the opening in the cover and engages the sensor. The spherical force transfer element is adapted to receive an input force and is configured, upon receipt of the input force, to transfer the input force to the sensor.
In another embodiment, a force sensor system includes a substrate, a cover, a sensor, a processor, a load bearing element, and a force transfer element. The substrate includes a first side and a second side. The cover is coupled to the first side of the substrate, and has an inner surface, an outer surface, and an opening extending between the inner and outer surfaces. A wall structure extends from the inner surface that defines a sensor cavity and a processor cavity between the inner surface and the substrate. The sensor is mounted on the first side of the substrate and is disposed within the sensor cavity. The sensor is configured to generate a sensor signal representative of a force supplied to the sensor. The processor is mounted on the first side of the substrate and is disposed within the processor cavity. The processor is coupled to receive the sensor signal and is configured, upon receipt thereof, to supply a force sensor output signal. The load bearing element is coupled to the second side of the substrate and is configured to limit force transferred to the substrate. The force transfer element is disposed partially within sensor cavity and is movable relative to the cover. The force transfer element extends from the opening in the cover and engages the sensor. The force transfer element is adapted to receive an input force and is configured, upon receipt of the input force, to transfer the input force to the sensor.
In yet another embodiment, a force sensor system includes a substrate, a cover, a sensor, a load bearing element, and a force transfer element. The substrate includes a first side, a second side, and a plurality of cover alignment openings formed in the first side. The cover is coupled to the first side of the substrate, and has an inner surface, an outer surface, and an opening extending between the inner and outer surfaces. A wall structure extends from the inner surface that defines a sensor cavity between the inner surface and the substrate. The cover also includes plurality of cover alignment pins, each of which is disposed within one of the cover alignment openings. The sensor is mounted on the first side of the substrate and is disposed within the sensor cavity. The sensor is configured to generate a sensor signal representative of a force supplied to the sensor. The load bearing element is coupled to the second side of the substrate and is configured to limit force transferred to the substrate. The force transfer element is disposed partially within the sensor cavity and is movable relative to the cover. The force transfer element extends from the opening in the cover and engages the sensor. The force transfer element is adapted to receive an input force and is configured, upon receipt of the input force, to transfer the input force to the sensor.
Furthermore, other desirable features and characteristics of the force sensor system will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the preceding background.
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Thus, any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described herein are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary, or the following detailed description.
An embodiment of a force sensor system 100 is depicted in
As depicted most clearly in
The cover 104, plan views of which are depicted in
Before proceeding further it is noted that because the cover 104 is a separate element, rather than an integrated element as in some sensor systems, the specific configuration of the cover 104 may be changed at a relatively low cost, if needed or desired, since only the cover 104 configuration would change. The remainder of the force sensor system 100 would, however, not be affected. This provides the advantage of keeping change-over costs relatively low, while still being implemented relatively fast and easy.
With continued reference to
The force transfer element 108 may be variously configured and implemented, but in the depicted embodiment it is spherical in shape. The force transfer element 108 is disposed partially within sensor cavity 614 and is movable relative to the cover 104. More specifically, the force transfer element 108 extends from the opening 608 in the cover 104 and engages the sensor 106, and more particularly the diaphragm 126. The force transfer element 108 is adapted to receive an input force and is configured, upon receipt of the input force, to transfer the input force to the sensor 106.
It was previously noted that the substrate 102 includes a plurality of cover alignment openings 202 and that the cover 104 includes a plurality of cover alignment pins 602. The cover alignment openings 202 and the cover alignment pins 602 are disposed to provide proper alignment of the force transfer element 108 to the sensor 106. It will be appreciated that the force transfer element 108 may be installed before the cover 104 is coupled to the substrate 102, or it may be press fit into the opening 608 after the cover 104 is coupled to the substrate 102.
The processor 112 is mounted on the substrate 102 and disposed within the processor cavity 616. The processor 112, similar to the sensor 106, may be mounted on the substrate 102 via solder or other suitable means, but is also preferably mounted thereon via an adhesive 122. The processor 112 may be implemented as an application specific integrated circuit (ASIC), as a microprocessor, or as a microcontroller, just to name a few. In any case, the processor 112 is coupled to receive the sensor signal supplied by the sensor 106 and is configured, upon receipt thereof, to supply a force sensor output signal.
As depicted most clearly in
Referring now to
Those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. Some of the embodiments and implementations are described above in terms of functional and/or logical block components (or modules) and various processing steps. However, it should be appreciated that such block components (or modules) may be realized by any number of hardware, software, and/or firmware components configured to perform the specified functions. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. For example, an embodiment of a system or a component may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments described herein are merely exemplary implementations
The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal In the alternative, the processor and the storage medium may reside as discrete components in a user terminal
In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Numerical ordinals such as “first,” “second,” “third,” etc. simply denote different singles of a plurality and do not imply any order or sequence unless specifically defined by the claim language. The sequence of the text in any of the claims does not imply that process steps must be performed in a temporal or logical order according to such sequence unless it is specifically defined by the language of the claim. The process steps may be interchanged in any order without departing from the scope of the invention as long as such an interchange does not contradict the claim language and is not logically nonsensical.
Furthermore, depending on the context, words such as “connect” or “coupled to” used in describing a relationship between different elements do not imply that a direct physical connection must be made between these elements. For example, two elements may be connected to each other physically, electronically, logically, or in any other manner, through one or more additional elements.
While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.
