Abstract:
A switch assembly and method of using same comprises a switch assembly for operating a power take off unit on a lawn tractor, the switch assembly further includes a housing supporting a selectively locatable activation knob facilitated by an actuation assembly and an internal switch arrangement coupled to a printed circuit board within the housing. The internal switch arrangement comprises a microcontroller and switch for determining the relative position of the selectively locatable activation knob and provides a digital output signal for enabling or disabling a power take off unit based on the digital output signal.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
       [0001]    The following application claims priority to co-pending U.S. Provisional Patent Application Ser. No. 61/714,420 filed Oct. 16, 2012 entitled SWITCH ASSEMBLY AND METHOD OF USING SAME. The above-identified application is incorporated herein by reference in its entirety for all purposes. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to an electrical switch assembly, and more particularly to a switch assembly and method of using the same. In particular, the switch assembly provides a digital input/output that communicates the status and position of a PTO switch and knob with a remote control module for activating the operation of a designated device. 
       BACKGROUND 
       [0003]    Electrical switches using push button or plunger type switch actuators have many applications including use in automobile car doors, ignition circuits, power take-offs for lawn mowers and garden tractors, refrigerator doors, home appliances, and the like. These push buttons may be normally open, normally closed or a combination of the two. However, such conventional switches are typically high current and conduct or transfer power to an end device for operation. 
         [0004]    Further discussion relating to conventional switches, high current switches and their different constructions can be found in U.S. Pat. No. 5,528,007 entitled PLUNGER SWITCH AND METHOD OF MANUFACTURE that issued on Jun. 18, 1996 and assigned to the assignee of the present disclosure. U.S. Pat. No. 5,528,007 is incorporated herein by reference in its entirety by reference. 
       SUMMARY 
       [0005]    One example embodiment of the present disclosure includes a switch assembly and method of using same for operating a power take off unit on a lawn tractor, the switch assembly comprises a housing supporting a selectively locatable activation knob facilitated by an actuation assembly and an internal switch arrangement coupled to a printed circuit board within the housing. The internal switch arrangement comprises a microcontroller and switch, such as an optical or infrared switch for determining the relative position of the selectively locatable activation knob and provides a digital output signal for enabling or disabling a power take off unit. 
         [0006]    In another example embodiment of the present disclosure, the internal switch arrangement additionally comprises a plurality of switches for determining the multiple positions of the activation knob and status of the power take off unit. 
         [0007]    While in another example embodiment, the internal switch arrangement additionally comprises a plurality of switches, including any combination of magnetic, capacitive, inductive, and mechanical switches. 
         [0008]    Another example embodiment of the present disclosure includes a switch assembly for operating a device or performing a safety function on a lawn tractor. The switch assembly comprises a housing supporting a selectively locatable activation knob facilitated by an actuation assembly, the actuation assembly including: a support; a vane coupled to the support; at least one spring configured to bias the support to position the vane; and at least one non-contact sensor. The switch assembly also includes an internal switch arrangement coupled to a printed circuit board within the housing, the internal switch arrangement having a microcontroller, a switch in communication with the microcontroller, the switch configured to determine the relative position of the selectively locatable activation knob and providing a digital output signal for enabling or disabling operation of a lawn tractor device or lawn tractor safety function. The switch assembly further comprises a control module for receiving the digital output signal, the control module configured to decode the digital output signal to activate or deactivate the lawn tractor device or safety function, wherein the internal switch arrangement is configured to communicate with the at least one sensor of the actuation assembly, the internal switch mechanism being configured to determine the presence of the vane relative to the at least one sensor, and further wherein the actuation assembly is configured to position the knob such that the switch arrangement detects the position of the knob and forms the corresponding digital output. 
         [0009]    Another example embodiment of the present disclosure includes a method for operating a device or performing a safety function on a lawn tractor, comprising the steps of: providing a switch assembly that includes a housing supporting a selectively locatable activation knob facilitated by an actuation assembly, an internal switch arrangement coupled to a printed circuit board within the housing, the internal switch arrangement comprising a microcontroller and switch, and a control module configured to cooperate with the internal switch mechanism. The method further comprises the steps of positioning the selectively locatable activation knob into or out of the housing; determining the relative position of the selectively locatable activation knob using the internal switch mechanism; providing a digital output signal based on the relative position of the selectively locatable activation knob; receiving the digital output signal using the control module; decoding the digital output signal; and activating or deactivating the lawn tractor device or safety function based on the digital output signal. 
         [0010]    Another example embodiment of the present disclosure includes a switch assembly for operating a device or performing a safety function for power equipment, the switch assembly comprising: a housing supporting a selectively locatable activation knob facilitated by an actuation assembly; an internal switch arrangement coupled to a printed circuit board within the housing, the internal switch arrangement comprising a switch for determining the relative position of the selectively locatable activation knob and providing a digital output signal for enabling or disabling operation of a power equipment device or power equipment safety function, the activation knob movably connected to one of the switch arrangement and a vane and the switch. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The foregoing and other features and advantages of the present disclosure will become apparent to one skilled in the art to which the present disclosure relates upon consideration of the following description of the disclosure with reference to the accompanying drawings, wherein like reference numerals refer to like parts unless described otherwise throughout the drawings and in which: 
           [0012]      FIG. 1  is perspective view of a switch assembly constructed in accordance with one example embodiment of the present disclosure; 
           [0013]      FIG. 2  is a sectional view of  FIG. 1  illustrating the switch assembly in a first actuated position; 
           [0014]      FIG. 3  is a partial sectional view of  FIG. 1  illustrating the switch assembly in a second actuated position; 
           [0015]      FIG. 4  a block diagram of a system associated with the switch assembly and remote control module for activating operation of a device; 
           [0016]      FIG. 5  is a switch used within the switch assembly constructed in accordance with one example embodiment of the present disclosure; 
           [0017]      FIG. 5A  is a switch used within the switch assembly having multiple sensors constructed in accordance with another example embodiment of the present disclosure; and 
           [0018]      FIG. 5B  is a switch used within the switch assembly having differing types of sensors constructed in accordance with another example embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Referring now to the figures generally wherein like numbered features shown therein refer to like elements throughout unless otherwise noted. The present disclosure relates to an electrical switch assembly, and more particularly to a switch assembly and method of using the same. In particular, the switch assembly provides a digital input/output that communicates with a remote control module for activating the operation of a designated device. 
         [0020]    Conventional power-take-off (PTO) switches used in outdoor power equipment, such as lawn garden tractors enable the operation of the blades for cutting grass or weeds. Traditionally, for lawn garden tractors, activation of the PTO involves changing the state of a high current electrical load in a high current switch that powers an electric clutch on and off. An example of a high current plunger switch is further described in U.S. Pat. No. 5,528,007 entitled PLUNGER SWITCH AND METHOD OF MANUFACTURE, which is incorporated herein by reference in its entirety by reference. In conventional high current switches, the load typically carries between three (3) and six (6) amps. 
         [0021]    Referring now to  FIG. 1  is a switch assembly  10  constructed in accordance with one example embodiment of the present disclosure. The switch assembly of the subject disclosure employs the novel and advantageous use of low current digital signals in the range of 10-60 mA to communicate to a remote device that performs the switching. The switch assembly  10  of the present disclosure is not switching high current, but instead employs a method of detecting switch position in the switch assembly, which is conducive to low current applications. 
         [0022]    The switch assembly  10  while described as being used in the operation of a lawn tractor, could also be used in other forms of power equipment without departing from the spirit and scope of the present disclosure. Suitable examples of power equipment include, but is not limited to lawn tractors, push mowers, all terrain vehicles, marine vehicles, golf carts, and the like. 
         [0023]    The switch assembly  10  comprises a housing  12 , activation knob  14 , switch arrangement  16  (see  FIG. 4 ), actuation assembly  18  (see  FIGS. 3 ,  4 ), communication link  20 , and control module  42 . The knob  14  is actuated by the operator from a first or up position seen in  FIG. 2  to a second or down position seen in  FIG. 3 . The up and down movement of the knob  14  is facilitated by the actuation assembly  18  internal to the housing  12 . The actuation assembly  18  comprises a series of springs  22  biasing a support  24  coupled to a vane  26 , which in one embodiment includes a line of sight  28 . The line of sight  28  allows for the passage of light in one or more positions of the knob  14 , while using an infra-red transmitters/receivers  30 . In the illustrated example embodiment, the vane  26  is made from plastic and/or opaque material and the line of sight  28  is an aperture and/or made of translucent material. 
         [0024]    In the illustrated example embodiment results in the springs  22  provide a biasing of the vane  26  in an upward direction, (see arrow U in  FIG. 2 ). It should be appreciated that the springs could be equally constructed to bias the movement of the vane  26  downward, opposite the direction of arrow U without departing from the spirit and scope of the present disclosure. In an alternative example embodiment, the springs  22  could move the transmitters/receivers  30  while the vane  26  remains stationary. 
         [0025]    In an alternative example embodiments used for detecting the switch/knob  14  and more specifically the vane&#39;s position, the vane  26  is metal or magnetic such that the relative position of the knob  14  can be detected by various types of sensors R that include hall effect methods/sensors, capacitive sensors, inductive sensors, variable resistance elements, such as a potentiometer, mechanical contacts, and the like, collectively  31 , as best seen in  FIG. 5B . The sensors or switches R ( FIG. 5A ,  31  ( FIG. 5B ),  32  ( FIGS. 2 and 3 ) provide the position signal  37  to the PCB  34 . 
         [0026]    Internal to the housing  12  and part of the switch arrangement  16  is a printed circuit board (PCB)  34  that provides for switch assembly  10  and discrete knob  14  position detection and forms a digital output  35  based on the relative positions of the vane  26  and aperture  28 . The PCB  34  also provides some additional opportunities for features such as user indicators  36 , illustrating to the operator the relative position of the knob and activation of devices  70  such as the PTO. In one example embodiment, the user indicator  36  is a light or LED located at the top of the knob  14 . In an alternative example embodiment, the user indicator  36  is an audible device or combination of multiple illumination and audible devices. 
         [0027]    In the illustrated example embodiment, the PCB  34  includes a power supply  55 , such as battery power and ground  57 , and input/output terminals e.g.  33 ,  35 ,  36 , and  38 . The power supply  55  powers all features and functions of the switch arrangement  16 . The digital input/output  35  is provided on the third I/O terminal of the communication link  20 . The communication link  20  in the illustrated example embodiment is a pin connection for a wiring harness. 
         [0028]    An input  33  provides a position signal  37  from internal switch S configuration that is coupled to, and in communication with PCB  34 .  FIG. 5  illustrates an infra-red switch S configuration comprising emitters  50  and collectors  52  (collectively sensors R) that provide either a high or low position signals depending on the discrete location of the vane  26 /switch as is moves in the directions of arrow A when the knob  14  is actuated by the operators. The high or low signal results in the position signal  37  that is transmitted via output  35  to a control module  42 . Stated another way, when the switch knob  14  moves in up or down direction, one or more IR channels (TX-RX) becomes blocked or unblocked depending on the aperture  28 , the intended function, and the position of the knob, thus affecting the value of the position signal  37 . 
         [0029]    The PCB  34  provides the digital output signal  35  that indicates the relative position of the knob  14 /switch assembly  10 , which communicates its value to a control module  42 . The digital output  35  occurs either wirelessly via antenna  38  or through a direct line  40  to a corresponding input on the control module  42 . In the illustrated example embodiment, the control module  42  includes firmware, software, or some form of computer readable media capable of providing instructions for operation to one or more devices  70 , such as a PTO, based on the output signal  35 . It should be appreciated by those skilled in the art that such switch assembly  10  could be used in any number of safety applications and types of switches without departing from the spirit and scope of the present disclosure. 
         [0030]    The control module  42  once receiving the digital output signal  35  communicates an enablement or disablement signal  43  to a device or safety function  70  on the lawn equipment that includes a higher power requirement of 3 to 6 amps, for example turning on or off a power-take-off (PTO) or engine. For example, the signal  43  based on the switch  14  position may disengage a PTO or turn on the engine depending on the software programming of the PCB  34  and various combinations that exist. 
         [0031]    In the illustrated example embodiment of  FIGS. 2-5 , a switch assembly  10  is shown. The switch assembly  10  includes a three-pin integral connector  20 ; a circuit board  34  that supports a microcontroller M that provides the digital output signal  35  based on the position signal  37  generated by the switch S. The microcontroller M is in communication with the switch S. In the illustrated example embodiment of  FIG. 5 , switch S includes an infrared transmitter/receiver pair  50 / 52  that detects switch  10 /knob  14  position, and provides an output for an LED  36  and position signal  37 . The two springs  22  bias the switch vane into the down or second position. 
         [0032]    In an alternative example embodiment illustrated in  FIG. 5A , the multiple sensors R are used that include infrared transmitter/receiver pairs  50 / 52   a  and  50 / 52   b . The sensors R transmit the location of the switch  14  based on the location of the vane  26  and/or aperture  28  and the passage of light therethrough, as would be appreciated when looking at various positions A and B of the vane an aperture. As the switch  14  is further depressed, it moves from position A to B, thus blocking the signal at B (shown) until the aperture  28  is centered about sensors  50   b ,  52   b.    
         [0033]    The microcontroller M includes firmware, software, or some form of computer readable media capable of reading the position signal  37  and providing the digital output  35  based thereon. While in an alternative example embodiment, the micro controller is replaced with an application specific analog circuit or discrete circuitry. The switch assembly  10  includes a contact-less switch that provides a digital output signal for the operation of a device  70  (or the non-operation of a device as safety function/operation, e.g. turning on a blade, PTO, or engine) through a remote control module  42 . Based on its intended function, the switch assembly may include one or multiple IR channels (TX-RX), a single channel being illustrated in  FIG. 5 . The infrared channel(s) are controlled by the onboard microcontroller M to detect blocked or unblocked channel and determine the position of the knob  14 . 
         [0034]    In one example embodiment, the switch assembly  10  reports the status and position of the switch  10 /knob  14  via a serial communication link. In another alternative example embodiment, the switch assembly  10  is used in a master slave configuration to interface the control module  42 . Advantageously, in the illustrated example embodiment, there is no exposure of external light to the infra-red switch/channels TX/RX or printed circuit board  34 , since both are contained within the switch assembly housing  12 . 
         [0035]    As used herein, terms of orientation and/or direction such as upward, downward, forward, rearward, upper, lower, inward, outward, inwardly, outwardly, horizontal, horizontally, vertical, vertically, distal, proximal, axially, radially, etc., are provided for convenience purposes and relate generally to the orientation shown in the Figures and/or discussed in the Detailed Description. Such orientation/direction terms are not intended to limit the scope of the present disclosure, this application and the invention or inventions described therein, or the claims appended hereto. 
         [0036]    What have been described above are examples of the present invention. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present invention, but one of ordinary skill in the art will recognize that many further combinations and permutations of the present invention are possible. Accordingly, the present invention is intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims.