Abstract:
A control handle for electro-mechanical devices, such as the brakes of a train or other vehicle, is disclosed. The control handle incorporates elements for electrical switching as well as elements for measuring the angle of rotation between the control handle&#39;s rotating portion and its stationary portion. Some of the switching elements and measuring elements are combined onto a single printed circuit board in order to reduce size, complexity, and cost.

Description:
TECHNICAL FIELD 
   Embodiments relate to a novel and improved control handle. Embodiments also relate to control handles containing both electrical switches and a spiral position sensor as integral elements. 
   BACKGROUND 
   Prior control handles are typically implemented with pneumatic, mechanical, or electrical hardware. In high reliability applications, such as for brake systems for locomotives, the control handles are almost entirely implemented with pneumatic or mechanical linkages. Control handles implemented with electrical hardware are disclosed in two published patent applications, incorporated here by reference, numbered 20040168606 and 20040168539. The control handles disclosed in those applications are superior to previous handles because they are smaller, easier to maintain, and more reliable. 
   Spiral sensors are a type of non-contact robust position sensor that is disclosed in U.S. Pat. No. 5,815,091, also incorporated by reference. In essence, a spiral sensor consists of 2 parts, one that moves in relation to the other. The output of the sensor is a measurement of the relative displacement between the two parts. Applications 20040168606 and 20040168539 disclose, but do not claim, using Spiral Sensors in a control handle. Applications 20040168606 and 20040168539 also disclose a control handle wherein contact switches are used to detect handle position. However, they do not disclose a control handle in which both contact switches and a Spiral sensor are used. Furthermore, they do not disclose a control handle wherein electrical switching elements and Spiral sensor elements are combined on the same printed circuit board. 
   The present invention combines electrical switches and Spiral sensing to overcome limitations in the prior art. 
   BRIEF SUMMARY 
   In accordance with an aspect of the embodiments a control handle is here described. By pushing and pulling on the handle, a person causes a hub mounted inside a stationary mounting block to rotate. The hub is part of a rotating assembly that includes the handle, shaft, hub, Spiral resonator and switch trace board, and a Spiral insulating cup. The stationary mounting block is part of a non-moving assembly including the block itself, a switch contact, a Spiral track and main board, and a Spiral insulating cup. The switch traces on the Spiral resonator and switch trace board and the switch contact interact to activate and deactivate electrical circuits. The Spiral resonator on the Spiral resonator and switch trace board and the Spiral track on the Spiral track and main board interact to produce a measurement of the relative angular offset between the Spiral track and the Spiral resonator. As such, rotation of the hub causes electrical switching and a changing measurement of the angular offset. The electrical circuits and the position measurement can be used to control electro-mechanical hardware, such as the brakes on a locomotive. 
   In accordance with another aspect, a movable shaft, connected to a moveable element is moved. The motion causes the moveable element to move in relation to a stationary element. The moveable element is part of a moveable assembly that includes the shaft, moveable element, Spiral resonator and switch trace board, and a Spiral insulating element. The stationary element is part of a non-moving assembly containing stationary element, a switch contact, a Spiral track and main board, and a Spiral insulating element. The geometry of the entire apparatus is not constrained to any one type of motion. For example, the motion could be along a line, along a curve or on a plane. The result of moving the moveable element in relation to the stationary element is electrical switching and a measurement of relative position. The electrical circuits and the position measurements can also be used to control electro-mechanical hardware, such as the brakes on a locomotive. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying figures, in which like reference numerals refer to identical or functionally similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the background of the invention, brief summary of the invention, and detailed description of the invention, serve to explain the principles of the present invention. 
       FIG. 1  illustrates a control handle wherein a stationary assembly supports a rotating assembly in accordance with an aspect of an embodiment; 
       FIG. 2  illustrates the elements making up a rotating assembly in accordance with an aspect of an embodiment; 
       FIG. 3  illustrates the elements making up a stationary assembly in accordance with an aspect of an embodiment; 
       FIG. 4  illustrates a Spiral resonator and trace board in accordance with an aspect of an embodiment; 
       FIG. 5  illustrates a Spiral track and main board in accordance with an aspect of an embodiment; 
       FIG. 6  illustrates a Spiral insulator cup in accordance with an aspect of an embodiment; 
       FIG. 7  illustrates a switch contact in accordance with an aspect of an embodiment; 
       FIG. 8  illustrates a switch contact interacting with a Spiral resonator and trace board in accordance with an aspect of an embodiment; 
       FIG. 9  illustrates a block diagram of a Spiral sensor in accordance with an aspect of an embodiment; 
       FIG. 10  illustrates processing equipment coupling the output from a control handle into vehicle brakes in accordance with an aspect of an embodiment; and 
       FIG. 11  illustrates a rotating hub with detents interacting with a pawl in accordance with an aspect of an embodiment. 
   

   DETAILED DESCRIPTION 
   The present invention is a control handle similar to those currently used to control the brakes of a train. It is an advance over the prior art handles because it combines elements of electrical switching with a Spiral position sensor. An overview of features of a control handle is shown in  FIG. 1 . The control handle of  FIG. 1  has a grip  1  that a person can grasp and move back and forth. Moving the grip  1  causes the shaft  2  on which the grip  1  is mounted to also move. The shaft  2  is mounted on a rotating assembly  3  such that moving the shaft  2  causes the rotating assembly  3  to rotate. The rotating assembly  3  is mounted to a stationary assembly  4  in a manner that allows the rotating assembly  3  to rotate while the stationary assembly  4  remains still. Techniques for mounting the rotating assembly  3  to the stationary assembly  4  are common and include, but are not limited to, axles, bushings, and bearings. 
   A rotating assembly  3  is shown in  FIG. 2 . It is made of a number of parts. In the preferred embodiment, those parts are a hub  5 , rotating Spiral insulator cup  6 , and Spiral resonator and trace board  7 . The hub  5  is a structural member intended to provide support to other parts of the rotating assembly  3  and to provide a mechanism allowing rotational movement of the rotating assembly  3 . The rotating Spiral insulator cup  6  is directly attached to the hub  5 . The Spiral resonator and switch trace board  7  is attached to the hub  5  such that it lies mostly within the Spiral insulator cup  6 . 
   A stationary assembly is shown in  FIG. 3 . It is made of a number of parts. In the preferred embodiment, those parts are a stationary mounting block  8 , a stationary Spiral insulator cup  9 , a Spiral track and main board  10 , and a switch contact  11 . The stationary mounting block  8  is a structural member intended to provide support to other parts of the stationary assembly  4  and to provide a mechanism allowing rotational movement of the rotating assembly  3 . The stationary Spiral insulator cup  9  is directly attached to the stationary mounting block  8 . The Spiral track and main board  10  is attached to the stationary mounting block  8  such that it lies mostly within the stationary Spiral insulator cup  9 . The switch contact  11  is attached to the stationary mounting block  8  such that it may interact with the switch traces  14 , as discussed later. 
   A Spiral resonator and switch trace board  7  is shown in  FIG. 4 . In the preferred embodiment, it is a round printed circuit board  12  on which is printed a Spiral resonator  13 , switch traces  14 , and a continuous trace  15 . The Spiral resonator and switch trace board  7  is attached to the hub inside the Spiral insulator cup and rotates along with the hub. The switch traces  14  and continuous trace  15  are placed such that they interact with the switch contact  11  mounted on the Spiral track and main board  10  shown in  FIG. 5  and  FIG. 3 . The Spiral resonator  13  is placed such that it will interact with the Spiral track  19 , shown in  FIG. 5 , printed on the Spiral track and main board  10  shown in  FIG. 3 . A unique element of the present invention is that the Spiral resonator  13  and the switch traces  14  are printed on the same printed circuit board  12 . 
   A Spiral track and main board  10  is shown in  FIG. 5 . In the preferred embodiment, it is a round printed circuit board  20  on which is printed a Spiral track  19  and on which is mounted a switch contact  11  and the circuit components  18  for the Spiral sensor. The switch contact  11  and circuit components  18  do not need to be mounted on the Spiral track and main board  10  in order to embody the present invention. They are mounted there in the preferred embodiment because it is convenient to do so. Regardless of where the circuit components for the Spiral sensor are mounted, they must be electrically connected to the Spiral track  19 . Regardless of how the switch contact  11  is mounted, it must be able to interact with the switch traces  14 . 
     FIG. 6  shows a spiral insulator cup  16 . Spiral sensors measure the relative offset between a Spiral resonator  13  and a Spiral track  19  by detecting the magnetic field coupling between them. The measurement can be affected by external magnetic fields. Spiral insulators shield the Spiral track  19  and Spiral resonator  13  portions of the sensor from external magnetic fields. The rotating Spiral insulator cup  6  in the rotating assembly  3  is intended to fit with the stationary Spiral insulator cup  9  in the stationary assembly such that the two cups enclose a space that is shielded from magnetic fields that exist outside that space. In some applications, the external magnetic fields are not severe enough to significantly interfere with Spiral sensing. In such applications, the Spiral insulator cups are not required to be part of the control handle assembly. 
     FIG. 7  shows a switch contact  11 . Any similar switch contact can be used in the preferred embodiment. Switch contact strips  22  are the parts of the switch contact  11  intended to touch the switch traces  14  as shown in  FIG. 8 . Although it can not be seen in  FIG. 8  because a black contact strip vanishes against the black switch trace behind it, the switch contact  11  of  FIG. 8  does have a contact strip touching a switch trace. The switch contact  11  is made of an electrically conducting material. As shown in  FIG. 8 , the purpose of the switch contact  11  is to activate an electrical circuit when electrical current can flow into one switch trace  14 , into a switch contact strip  22 , though the switch contact  11 , out another switch contact strip  22  and into another switch trace  14  or continuous trace  15 . 
   The design, manufacture, and use of switch traces  14 , continuous traces  15 , and switch contacts  11  can be understood by those skilled in the art of switching circuits. Similarly, the switch contact  11  can be used to deactivate an electrical circuit when electric current cannot flow because the switch contact strips  22  are not touching the switch traces  14  properly. In the preferred embodiment, rotation of the switch traces with respect to the contact switch completes and breaks electrical circuits. A continuous trace  15  interacts with the switch contact  11  the same way as a switch trace  14  except that switch contact strips  22  are in continuous contact with the continuous trace  15 . The continuous trace in the preferred embodiment of the present invention is not required to be in all embodiments of the present invention. Similarly, there can be multiple switch contacts in a different embodiment of the present invention even though the preferred embodiment has only one. The status of the electrical circuits as activated or deactivated can be used as switched control signals. The switched control signals can be used to control the brakes of a vehicle, such as a train. 
     FIG. 9  shows many of the component parts of the Spiral sensor used in the preferred embodiment. Spiral sensor technology is fully described in U.S. Pat. No. 5,815,091, which is incorporated by reference. In the preferred embodiment, a microcontroller  28  sends control signals to Spiral drive circuitry  24 . The Spiral drive circuitry  24 , under control from the microcontroller  28 , sends electric current into the Spiral track  19 . The electric current traveling through the Spiral track  19  creates a magnetic field. The Spiral resonator  13 , being in proximity to the Spiral track  19 , is within the magnetic field. The magnetic field causes electrical current to flow in the Spiral resonator  13 , resulting in a change in the magnetic field itself. 
   The Spiral resonator  13  induced changes in the magnetic field also affect the electrical current in the Spiral track  19 . Changing currents in the Spiral track  19  also changes the voltage in the Spiral track  19 . A peak detector  23  monitors the changing voltage and sends the peak voltage to a gain stage  30 , which amplifies it. The amplified voltage from the gain stage  30  is then read, via an analog to digital converter  31 , by the microcontroller  28 . The microcontroller  28  uses the measured voltage to calculate the angular position of the Spiral resonator  13  in relation to the Spiral track  19  and sends that calculation out as the Spiral sensor output  29 . The Spiral sensor output  29  of the Spiral resonator can be used as a control signal. The control signal can be used to control the brakes of a vehicle, such as a train. 
   An aspect of the embodiment illustrated in  FIG. 9  is the use of a microprocessor. Other functionally equivalent electrical and electronic circuits can be used instead of a microprocessor. An oscillator can supply a signal to the Spiral drive circuitry  24 . The output of the gain stage  30  can be used directly as a control signal. The gain stage  30  output can also be passed through analog or digital conditioning circuitry to produce the sensor output  29 . 
   The preferred embodiment produces a control output that can include the Spiral sensor output and switched control signals. As shown in  FIG. 10 , the control handle  32  can pass its control output to a processor  33 . The processor  33  can then operate on the control output and thereby alter it. The altered control output can then be used to control, for example, the brakes  34  of a vehicle, such as a train. 
   As shown in  FIG. 11 , the preferred embodiment uses a pawl  35  and detent  36  mechanism to limit hub  5  movement, supply operator feedback, and help the hub  5  maintain position. The pawl  35  is pressed against the hub  5 . When a detent  36  aligns with the pawl  35 , the pawl  35  is pressed into the detent  36 . The effect is to pull the hub  5  into a position aligning the pawl  35  with the detent  36  and to increase the amount of force needed to move the hub  5  away from the aligned position. A human operator can feel the pull and the increased force. The increased force also helps keep the hub  5  in place. Finally, the detent  36  can be shaped such that the pawl  35  can not be forced back out via rotational force in one direction or in any direction. 
   An advantage of the present invention is that it is smaller, and less expensive than other control handles. A control handle with multiple Spiral sensors and switching elements can be built. In the preferred embodiment, all of the Spiral elements and switching elements are on one side of the hub  5 . All those elements can be duplicated on the other side of the hub to produce a control handle with multiple or redundant outputs. Similarly, those elements can also be put onto the same printed circuit board to again produce a control handle with multiple or redundant outputs. 
   The preferred embodiment is restricted to rotary movement. Another embodiment of the invention removes that restriction to allow the moveable portion of the control handle to move along a line, plane, or curve. The alternative embodiments would operate similarly to the preferred one, but for some minor changes in certain elements. The minor changes are the result of replacing the rotationally constrained elements with ones that are not so constrained. The hub becomes a moveable member. The Spiral cups become Spiral insulating forms. The stationary mounting block becomes a stationary member. The function of these parts remains the same while their range of allowed movement is no longer constrained to rotation. 
   The embodiment and examples set forth herein are presented to best explain the present invention and its practical application and to thereby enable those skilled in the art to make and utilize the invention. Those skilled in the art, however, will recognize that the foregoing description and examples have been presented for the purpose of illustration and example only. Other variations and modifications of the present invention will be apparent to those skilled in the art, and it is the intent of the appended claims that such variations and modifications be covered. 
   The description as set forth is not intended to be exhaustive or to limit the scope of the invention. Many modifications and variations are possible in light of the above teaching without departing from the scope of the following claims. It is contemplated that the use of the present invention can involve components having different characteristics. It is intended that the scope of the present invention be defined by the claims appended hereto, giving full cognizance to equivalents in all respects.