Patent Publication Number: US-2007120354-A1

Title: Illuminated ski pole discs

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is a continuation of U.S. patent application Ser. No. 11/239,931, filed Sep. 30, 2005, which claims the benefit of U.S. Provisional Patent Application No. 60/646,068, filed Jan. 21, 2005, both of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates to an illuminated ski pole disc for use on a ski pole that functions to provide snow resistance when a skier thrusts the pole into the snow. The illuminated ski pole disc may alternatively or also emit sound, form or imprint an information-imparting image in the snow, and/or have an information-imparting top surface. The invention also relates to methods of imparting information and advertising.  
      2. Related Art  
      Ski poles are used by snow skiers to help balance themselves as they ski over uneven terrain or around curves. A conventional ski pole has a bottom end and a top end having a handle area by which the ski pole is manipulated by the user. A disc, sometimes referred to as a basket or wheel, is employed near the bottom end of the ski pole to provide snow resistance, and thus a measure of support, when the user thrusts the pole into snow.  
      Various geometrical designs have been employed for ski pole discs. The typical disc is circular, with a hub, an outer rim, and integral radial ribs or spokes. The hub may be plastic, metal, rubber, or the like and may be pivotally mounted to the ski pole. The rim may be plastic, metal, or similar materials, and the ribs are typically plastic or rubber. Examples of this general type of configuration are shown in U.S. Pat. No. 3,163,437 (Phillipson); U.S. Pat. No. 3,199,886 (Dover); U.S. Pat. No. 3,250,545 (Cameron); U.S. Pat. No. D169,644 (Weiss); and U.S. Pat. No. D196,847 (Miller). These conventional designs suffer from certain disadvantages. For example, they tend to be rather heavy and expensive to manufacture, provide a relatively small snow resistance, and are subject to getting caught on obstacles, such as branches and twigs. In addition, these discs are not useful for emitting light and/or sound or for forming information-imparting images in the snow. Nor do these discs provide an information-imparting top surface.  
      Other designs have sought to overcome the disadvantages discussed above by employing a largely solid disc, as shown, for example, in U.S. Pat. Nos. 3,743,311 (Giambazi); U.S. Pat. No. D279,024 (Nordgren et al.); U.S. Pat. No. D302,288 (Filice); U.S. Pat. No. D315,591 (Ehlert); U.S. Pat. No. D316,132 (Ehlert); U.S. Pat. No. D343,217 (Jarvinen); and U.S. Pat. No. D351,887 (Zimmerman). The solid discs tend to provide greater snow resistance due in part to their shape and larger surface area. However, these discs also are not useful for emitting light and/or sound or for forming information-imparting images in the snow or imparting information to a viewer of a top surface of the disc.  
      Illumination has been incorporated into the shaft or handle of a ski pole, as shown, for example, in U.S. Pat. No. 4,023,817 (Lah et al.); U.S. Pat. No. 4,066,889 (Hodgson); U.S. Pat. No. 4,129,311 (Hodgson); U.S. Pat. No. 4,206,445 (Steinhauer); U.S. Pat. No. 5,056,821 (Fierro); U.S. Pat. No. 5,149,489 (Crews); U.S. Pat. No. 5,271,640 (Potochick et al.); U.S. Pat. No. 6,152,491 (Queentry); and Japanese Patent Application Publication No. 05-177027. U.S. Pat. No. 5,039,128 shows a light attached to a ski. However, because these configurations involve lights installed in the shaft or handle of the ski pole, they are not designed to be readily replaceable components for use with a skier&#39;s existing ski poles and thus, are not amenable to being marketed separately as an add-on feature for existing equipment. In addition, such configurations do not have lights that are triggered automatically, nor do they have multi-color lights that operate in predetermined and/or random sequences.  
     SUMMARY OF THE INVENTION  
      In one aspect, the present invention provides a ski pole disc for attachment to a ski pole, including a body extending in a direction substantially perpendicular to the ski pole and having a hole in a central portion thereof to receive the ski pole. An electronic circuit is positioned in the body, and the body is configured to allow illumination generated by the electronic circuit to be visible through the body.  
      Embodiments of the present invention may include one or more of the following features.  
      The electronic circuit may include a motion-activated circuit, and the illumination may be initiated in response to a signal from the motion-activated circuit. The ski pole disc may include a sound generation circuit, and the generation of sound by the sound generation circuit may be initiated in response to a signal from the motion-activated circuit.  
      The body of the ski pole disc may include a housing. The housing may include a bottom housing element having a hole in a central portion thereof to receive the ski pole and a top housing element having a hole in a central portion thereof to receive the ski pole. The top housing element may cooperate with the bottom housing element to house the electronic circuit. The bottom housing element and the top housing element may have respective edge portions that are substantially the same size and shape, and the edge portions may be sealed together to prevent water from entering the housing. The housing may include an inner surface substantially perpendicular to the ski pole and having recessed portions configured to hold elements of the electronic circuit. The bottom housing element may be configured to allow the illumination generated by the electronic circuit to be visible through the bottom housing element.  
      The body of the ski pole disc may further include a resistance layer attached to the housing and extending beyond the housing in a direction substantially perpendicular to the ski pole. The top housing element and the resistance layer may be configured to allow the illumination generated by the electronic circuit to be visible through the top housing element and the resistance layer. The resistance layer and the housing both may be formed of plastic, and the resistance layer may be formed of a softer plastic than the housing.  
      The resistance layer may be formed on top of or beneath the housing by injection molding. The resistance layer may be formed around the housing by injection molding to at least partially cover the top and bottom of the housing. The resistance layer may be configured to form an image in the snow that imparts information to a person viewing the formed image. The resistance layer may be configured to impart information to a person viewing a top surface of the resistance layer.  
      The electronic circuit of the ski pole disc may include light-emitting devices and a processor configured to control the light-emitting devices in a predetermined sequence. The electronic circuit may be formed on printed circuit boards (PCBs) arranged around the periphery of the body. The light-emitting devices arranged on each of the PCBs may include a variety of colors. The light-emitting devices may be light emitting diodes (LEDs).  
      The electronic circuit may further include a power source connected to provide power to the light-emitting device and the processor. The power source may include a battery or batteries, which may be arranged around a periphery of the housing. The power source may include a number of batteries arranged in a stack. The power source may include a solar cell connected to recharge the power source.  
      In another aspect, the invention provides methods of imparting information and advertising. In the information-imparting aspect, the disc may include a bottom surface configured to form an image in the snow that imparts information to a person viewing the formed image and/or a top surface that imparts information to a person viewing that surface.  
      Embodiments of the present invention also may include one or more of the following features. The lights (or single light) may be activated by motion and/or impact of the ski pole. The lights may be activated by temperature or a light-level detector. The lights may be continuous or flashing, including various timings, patterns and sequences of flashing. There may be a plurality of sets of LEDs, each set being provided in a lighting housing installed in the disc. There may be four sets of LEDs, each set having three LEDs, but this is merely one example of a possible configuration. Various numbers of LEDs, in various groupings, are possible. The lights may be powered by a battery or plurality of batteries installed in the disc.  
      In other embodiments, the ski pole disc may emit a sound or sounds in addition to or in lieu of light. The sound or sounds may, for example, impart information, may be nonsensical, or may be a voice and/or music message.  
      In other embodiments, the imparted information may be at least one of commercial information, advertising, political information, personal identification, organizational identification, and team identification information. The formed image may include a text portion and/or a pictorial portion. The formed image also may include a logo. A ski pole may be provided that includes the disc.  
      These and other objects, features and advantages will be apparent from the following description of the preferred embodiments of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a top perspective view of a resistance layer of an illuminated ski pole disc in accordance with an embodiment of the present invention.  
       FIG. 2  is an exploded perspective view of the illuminated ski pole disc.  
       FIG. 3  is a top perspective view of an embodiment in which the resistance layer is formed on the bottom of the housing.  
       FIG. 4  is a top perspective view of an embodiment in which the resistance layer is formed on the top and bottom of the housing.  
       FIG. 5  is a top perspective view of the bottom housing element.  
       FIG. 6  is a top perspective view of the top housing element.  
       FIG. 7  is bottom perspective view of the illuminated ski pole disc.  
       FIG. 8  is a schematic of the electronic circuit.  
       FIG. 9  is an isometric illustration of a skier moving on skis over a snow surface and employing ski poles in both her left and right hands.  
       FIG. 10  is an enlarged view of a butterfly formed in a snow surface by the ski pole disc of  FIG. 9 .  
       FIG. 11  is an enlarged plan view of the bottom surface of a ski pole disc, wherein an image representing a butterfly is formed in the snow surface each time the disc contacts the snow surface.  
       FIG. 12  is an elevation, slightly isometric side view of the ski pole disc of  FIG. 11 .  
       FIG. 13  is an end view, slightly isometric of the ski pole disc of  FIG. 11 .  
       FIG. 14  is a top view of an alternate design of a ski pole disc secured to the bottom end portion of a ski pole, the ski pole being shown broken away.  
       FIG. 15  is an isometric bottom view of a ski pole disc as affixed to the bottom end portion of a ski pole with the ski pole shown broken away.  
       FIG. 16  is an isometric, exploded top view of a ski pole disc and insert. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      The ski pole disc of the present invention, in addition to providing snow resistance when a skier thrusts the pole into the snow, also has an illumination system to emit continuous or flashing lights. As further discussed below, the lights may be activated by the motions of the skier as he or she uses the ski poles via an LED circuit embedded in the ski pole disc. The LED circuit may be powered by a battery or batteries that are also embedded in the ski pole disc.  
      The ski pole disc is designed to accommodate a housing (or housings) of the LED circuit (or circuits) and battery (or batteries). The disc may be decorated to allow the product to be offered in attractive colors, and may be opaque, translucent, or transparent. Additionally, the illuminated ski pole disc may be designed to utilize any or all of the designs discussed below for imparting information.  
      The lights may be motion-activated, so as to be activated for a specific time to allow the lights to go on and off as the skier uses the ski pole. Alternatively, the lights may stay on continuously or for a relatively long duration. These design decisions may be made prior to manufacture of the ski pole disc and may or may not be features that are adjustable by a user. Of course, the lights may be multi-colored or of a single color. The ski pole disc also may be designed to generate a sound or sounds, in addition to light or in lieu of light. These sounds may be, for example, non-intelligible noises, an information-imparting sound, a voice message or music.  
      As shown in the particular embodiment of  FIG. 1 , the illuminated ski pole disc  100  has a snow resistance layer  110  having a generally round shape with a scalloped outer edge, e.g., round with a number of concave cutout portions  115 . However, a nearly infinite variety of shapes is possible, as further discussed below. The resistance layer  110  has openings  120 , or portions that are translucent or transparent, to allow the lights installed in the disc to be visible from the top of the disk. The resistance layer also has an opening  130  in the center to allow installation of the disc onto a ski pole, as further discussed below.  
      As shown in  FIG. 2 , a housing  200 , having a top housing element  210  and a bottom housing element  220 , is positioned beneath the resistance layer  110  of the disc  100  to enclose an electronic circuit, such as for example, an illumination circuit  230 . The illumination circuit includes an arrangement of batteries  240 , printed circuit boards (PCBs)  250  and wiring (not shown in this view) that is sealed in the housing  200 . The housing  200  is similar in shape to the resistance layer  110 , but may be somewhat smaller. In this particular embodiment, the protruding points  255  around the outer edge of the housing have a more rounded shape than the corresponding protruding structures  260  of the resistance layer  110 .  
      The housing  200  may be formed of any appropriate translucent or transparent material, such as for example plastic. The housing  200  also may be formed of an opaque material, e.g., plastic, metal, etc., with translucent or transparent windows formed therein. In this embodiment, the top  210  and bottom  220  housing elements are formed of a hard, translucent plastic, e.g., polypropylene, in an injection molding process and are sealed together so as to form a waterproof housing  200  for the illumination circuit  230 . The top  210  and bottom  220  housing elements may be sealed in a number of ways, such as for example by ultrasonic welding or adhesive. The top  210  and bottom  220  housing elements may include edges that are configured to provide a snap fit between the elements. The snap fit may be augmented by, for example, adhesives, sealants, or a coating to ensure a waterproof fit.  
      Once the housing  200  has been sealed with the illumination circuit  230  inside, the resistance layer  110  is formed on the housing  200 . For example, the resistance layer  110  may be formed using a second injection molding process in which the housing  200  is inserted into the injection molding machine and the resistance layer  110  is molded over the top surface of the top housing element  210 . Alternatively, the resistance layer  110  may be formed separately (e.g., using injection molding) and attached to the housing  200  using adhesive. Alternatively, the resistance layer  110  may be attached to or molded over the top surface of the top housing element  210  alone, and then, after the electronic circuit  230  is installed in the housing  200 , the top  210  and bottom  220  housing elements may be sealed together, e.g., by ultrasonic welding or adhesive. The top surface of the top housing element  210  may have holes or ridges formed therein to accept material from the resistance layer  110  during the molding process, thereby providing an interlocking fit between the housing  200  and the resistance layer  110 .  
      The resistance layer  110  may be formed of any suitable material, but in this embodiment, it is formed of plastic that is somewhat softer than the plastic of the housing  200 , e.g., thermal polyethylene. The softer material allows the resistance layer  110  to function in a manner similar to a traditional ski pole disc or basket, in that it is flexible and can withstand the shock and abuse associated with ski pole use. As noted above, the resistance layer  110  may be transparent or translucent, or may be opaque with widows or openings  120  (see  FIG. 1 ). The resistance layer  110  may be provided in wide array of colors and shapes.  
      In an alternative embodiment, as shown in  FIG. 3 , the resistance layer  110  may be formed on the bottom of the housing  200 . For example, the resistance layer  110  may be formed using a second injection molding process in which the housing  200  is inserted into the injection molding machine on top of the resistance layer  110  and the resistance layer is molded to the bottom surface of the bottom housing element  220 . Alternatively, the resistance layer  110  may be formed separately (e.g., using injection molding) and attached to the bottom surface of the bottom housing element  220  using adhesive. In this alternative embodiment, the resistance layer  110  may be opaque, as the illumination would be visible through the top housing element  210 . In addition, the resistance layer  110  may be attached to or formed on the bottom housing element  220  alone, and then, after the electronic circuit  230  is installed in the housing  200 , the top  210  and bottom  220  housing elements may be sealed together, e.g., by ultrasonic welding or adhesive.  
      In a further alternative embodiment, as shown in  FIG. 4 , the resistance layer  110  may be formed such that both the top  210  and bottom  220  housing elements are at least partially enclosed within the resistance layer  110 . For example, the second injection molding process may be conducted so that the resistance layer  110  is formed over the top  210  and bottom  220  elements of the housing  200  and extends beyond the periphery of the housing  200  to form the outer surface of the ski pole disc. In such a case, the resistance layer  110  may have transparent or translucent portions or cut-out portions to allow the illumination to be visible through the resistance layer.  
      In other embodiments, the ski pole disc  100  may not have a resistance layer  110  at all, in which case the housing  200  may be formed with an extended edge portion to provide snow resistance. The extended edge portion may be provided on the top housing element  210 , bottom housing element  220 , or both.  
       FIG. 5  shows the bottom housing element  220 , which, in this embodiment, has a number of recesses  305 ,  310  formed on the periphery thereof to hold batteries  240  and PCBs  250  in place. For example, the bottom housing element  220  may have three cylindrical recesses  305  with a diameter of about 0.5 inches and a depth of about 0.125 inches configured to hold the batteries  240 . The recesses  305  may be sized to provide a snug fit for the batteries  240 , or may allow room for different battery types to be used. The battery recesses  305  may include a cylindrical metal lining (not shown) that extends partially out of the recess  305  in order to allow electrical contact with a terminal of the battery  240 . Alternatively, a battery clip (not shown) may be provided on the bottom of the recess  305  and electrically connected via a wire or other means to the illumination circuit  230 . The bottom housing element  220  also may contain shallower recesses  310  configured to receive the PCBs  250 , which in this embodiment, are round, but thinner than the batteries (about 30 mils thick). In an alternative embodiment, the batteries  240  may be arranged in a stack that is positioned in a recess in the housing  200 .  
      A variety of configurations for the bottom housing element  220  are possible. Specifically, the number of recesses  305 ,  310  for batteries  240  and PCBs  250  can vary depending upon the number of batteries or PCBs required for a particular design. Also, recesses may not be provided for the PCBs if the space between the top  210  and bottom  220  housing elements is sufficient. In addition, recesses may be provided in the top housing element  210  in lieu of or in addition to the recesses in the bottom housing element  220 . In alternative embodiments, the batteries  240  may be positioned in recesses, and the PCBs  250  may be positioned directly over the batteries, such that a contact on the underside of the PCB makes an electrical connection with a terminal of the battery.  
      The top housing element  210 , as shown in  FIG. 6 , is similar in shape to the bottom housing element  220 . As noted above, the top housing element  210  may have recesses formed therein (not shown) for receiving illumination circuit  230  components, e.g., batteries  240  and PCBs  250 . In this embodiment, the top housing element  210  is a translucent plastic, so as to allow light generated by the illumination circuit  230  to shine through the top of the housing.  
       FIG. 7  shows the underside of the ski pole disc  100 , and as noted above, the resistance layer  110  may be formed on the top of the housing  200 , e.g., by being injection molded onto the housing  200 . In the illustrated embodiment, the resistance layer  110  is larger than the housing  200  and therefore extends outward beyond the edge of the housing. This outer portion  505  of the resistance layer  110  provides additional resistance as the pole and disc  100  are thrust into the snow during use. The outer portion  505  also serves to protect the housing  200  from shock, because it is flexible and absorbs impact. For example, if the ski pole were to impact an object, the resistance layer  110  would help prevent contact between the object and the housing  200 . The bottom housing element  210  may have notches  510  formed around the periphery thereof, in order to provide additional resistance in snow and ice. Also, the recessed portions  305  holding the components of the illumination circuit  230 , e.g., the batteries  240 , may extend from the bottom of the housing.  
      As shown in  FIG. 8 , the illumination circuit  230  of this particular embodiment includes a number of interconnected PCBs, including a “server” PCB  810  connected to two “client” PCBs  820 . The server PCB  810  includes a microprocessor/microcontroller  830  (“controller”), which controls the activation of light emitting diodes (LEDs)  840  on the server and client PCBs. The number of server and client PCBs may vary depending upon various design considerations, such as for example, the size of the disc, the number of LEDs, and whether sound generation or other functionalities are included. For example, there may be one server PCB  810  and three or four client PCBs  820 .  
      Each PCB in this embodiment, including the server  810  and the clients  820 , has three LEDs  840  of multiple colors arranged on the surface thereof, e.g., one red, one yellow, and one green. Of course, a variety of colors and arrangements is possible. As a further example, there may be only one LED  840  per board, each of which is a different color, or there may be several LEDs  840  on each board of the same color, but differing from board to board. Moreover, the server PCB  810  may or may not have LEDs. The server PCB  810  may be connected to the client PCBs  820  to allow access to each individual LED  840 , or may allow access in certain color/location combinations, as discussed below.  
      As noted above, the illumination circuit  230  also includes a power source, such as for example, a number of batteries  850 , which may be positioned in recesses around the periphery of the housing  200 . Each battery  850  may be connected to a client PCB  820  positioned on top of the battery  850  (e.g., via a contact on the underside of the PCB) or adjacent to the battery  850  (e.g., via a wired connection). For example, there may be three batteries  850 , one associated with each of the server PCB  810  and two client PCBs  820 . Each client PCB  820  may, in turn, be connected to a power supply input (Vcc) of the server PCB  810 , which provides power for the entire illumination circuit  230 . Alternatively, the batteries  850  may be connected directly to the server PCB  810 , e.g., via a wired, series connection. The controller  830  on the server PCB, in turn, provides the power to illuminate all of the LEDs  840 , as further discussed below.  
      Referring again to  FIG. 8 , the controller  830  may be an in-circuit programmable controller with flash memory, for example, a PIC16F505, supplied by Microchip Technology, Inc. of Chandler, Ariz. The controller  830  has a number of bidirectional input/output (I/O) pins (RB 0 -RB 5  and RC 0 -RC 5 ), which output signals to drive the LEDs  840 , as described below. The controller  830  also has in-circuit serial programming input pins (ICSDAT, ICSPCLK, and Vpp), which may be accessible via a connector  855  to allow the controller  830  to be programmed during manufacture.  
      A switch  860  is connected to a reset port (MCLR) of the controller  830  to allow initiation of the program that controls the illumination of the LEDs  840  or other functionalities of the disc (e.g., sound generation). As noted above, the switch  860  may be motion-activated and may include a spring-loaded element. For example, the switch  860  may be implemented as a spring with a weighted end that is configured to bounce against an electrical contact (or multiple contacts) in response to motion of the disc. The sensitivity of the switch  860  is set to ensure that the device is not too easily activated, which may be annoying to the user and would tend to deplete the power source too quickly. Also, the switch  860  is not so insensitive as to require an undue movement of the disc to initiate the illumination sequence. Rather, the switch  860  is calibrated to be activated by the normal motions of skiing, so that the illumination sequence occurs frequently while the user is skiing, but does often occur when the ski pole disc is being transported or stored.  
      In the embodiment of  FIG. 8 , one of the terminals (e.g., the cathode  865 ) of each LED is connected to a single control line (K 1 , K 2 , and K 4 ) on each PCB so as to be activated together, which lessens the number of connections between the server PCB  810  and client PCBs  820 . The opposite terminal (e.g., the anode  870 ) of each LED  840  is connected to an individual control line (REDA, GRNA, YELA), each corresponding to a particular color, e.g., red, green, and yellow. Thus, each PCB  810 ,  820  has one common control line (K 1 , K 2 , and K 4 ) and three individual color control lines (REDA, GRNA, YELA). As an alternative, the LEDs  840  of a particular color on each PCB, e.g., all of the green LEDs, may be connected to be activated together.  
      Individual control of each LED  840  on each PCB  810 ,  820  may be achieved by using pulse-width modulation (PWM) control waveforms to provide time-division multiplexing of the control signals. For example, to activate a red LED on one client PCB and a green LED on another client PCB, the red LED control (REDA) and green LED control (GRNA) are activated using alternating PWM pulses, while the single control lines (K 1  and K 2 ) are also activated using alternating PWM pulses (e.g., such that the K 1  and REDA pulses are coincident and the K 2  and GRNA pulses are coincident, but offset in time from the K 1  and REDA pulses). As an alternative, a controller  830  with more numerous control outputs may be used, such that the outputs are connected to each individual LED  840  on each of the client PCBs  820 , as well as on the server PCB  810 .  
      PWM may also be used to control the brightness of the LED illumination. For example, PWM control waveform having an activation duty cycle of, e.g., about 20%, may be used to provide a desired level of illumination. Thus, PWM waveforms allow individual control of the LEDs, allow level control without requiring resistive elements, and lessen the overall system power requirements.  
      As noted above, the controller  830  runs a control program configured to illuminate the LEDs  840  in a predetermined sequence. In this embodiment, the LEDs  840  of each PCB  810 ,  820  are illuminated briefly in sequence, e.g., red, green, blue, one board at a time. The order of the colors corresponds to the positions of the LEDs, such that the light appears to progress in a circle around the PCB. The sequence starts with one PCB and then progresses around the periphery of the disc  100  until the LEDs of all of the PCBs have been illuminated. Thus, the light appears to follows a circular motion around the periphery of the disc  100 , as well as around each individual PCB  810 ,  820 . Then, the LEDs  840  of all of the PCBs  810 ,  820  are illuminated in this predetermined color sequence at the same time. In other words, all of the red LEDs are activated, followed by all of the green LEDs, followed by all of the blue LEDs, and this sequence is more rapid than the initial sequence. Of course, there are numerous possible sequences, involving different order and timing of illumination. The controller also may be programmed to generate random sequences or combinations of predetermined and random sequences.  
      In addition to LEDs  840 , the server  810  and/or client  820  PCBs may include sound generation circuit  875  and, a sound emitting device, such as for example, a speaker  880  or simple buzzer. The speakers  880  may be individually or collectively controlled by the sound generation circuit  875  using connections similar to those discussed above for control of the illumination. Alternatively, separate speakers may be provided in recesses around the periphery of the housing  200 . The sound generation circuit  875  may be programmed to emit a sequence of noises or sounds or music from the speakers  880  in concert with the illumination sequence.  
      In addition to the illumination and sound-emitting features discussed above, the ski pole disc  100  of the present invention also may incorporate image-imparting features, as shown in  FIGS. 9-16 .  FIG. 9  shows an example of the use of an image-imparting ski pole disc with illumination and/or sound features by a skier  10  having skis  12  and moving over a snow surface  14 . The skier  10  is shown using two ski poles  16 ,  18 , one in each hand. The ski poles  16 ,  18  are elongated and have a top end portion  20  and a bottom end portion  24 . Affixed to each of the ski poles  16 ,  18 , at the bottom end portion  24 , is an image-imparting ski pole disc with illumination and/or sound features  26 .  
      In the illustration of  FIG. 9 , each of the ski pole discs  26  imprints the snow surface  14  with an image that imparts information to someone viewing the image. The imparted information conveyed in the image may include, for example, commercial information, advertising, political information, religious information, sports-related information, nonsensical or humorous information, entertainment, style or fashion information, personal, organizational, or team identification information, etc. The image may include a likeness of a person, animal or object, and/or text, e.g., letters, numbers, words, and phrases. For example, the image may be a commercial image, e.g., a logo, with or without accompanying text, such as a name or trademark. In addition, as the skier applies normal skiing motions to the ski pole, the illumination sequence and/or sound sequence is activated, as discussed above.  
      In the arrangement of  FIG. 9  each of the ski pole discs  26  is configured to form an image in the snow surface  14 , each time the disc engages a snow surface, e.g., an image of a butterfly. That is, an imprinted image  28  is formed each time a ski pole disc  26  contacts a snow surface  14  that gives the visual impression of a butterfly. In this way, skier  10  leaves identification information along her ski tracks  30  that would help enable a skier following to identify the individual who has been along the same route previously.  
       FIG. 10  is an enlargement of one of the imprints  28  formed in snow surface  14 .  
       FIGS. 11-13  show more details of the ski pole disc  26  and shows end and side edges.  FIG. 11  shows specifically the bottom surface  32  of ski pole disc  26 , which may be the bottom surface of the resistance layer, if such layer is arranged on the bottom of the housing or surrounding the housing, as discussed above. The bottom surface is defined by an outer circumferential edge  34  that outlines the shape of the image that is to be imprinted in the snow surface. In this example, the circumferential edge  34  outlines the shape of a butterfly.  
      Formed in bottom surface  32  are a plurality of contoured recesses  36  configured to form the imprint of the intended image when the ski disc contacts snow surface  14 . The recesses  36  vary in size, shape, contour, depth, and so forth, so that taken together they form a contoured bottom surface within a peripheral edge  34  that forms an image-imparting imprint when the ski pole disc contacts a snow surface. Alternatively, the imprint of the intended image may be formed by bottom surface  32  having contoured raised surfaces that act to compact the snow to form corresponding contours in the snow surface.  
       FIGS. 14 and 15  show an alternative embodiment of an image-imparting ski pole disc, in this case identified by the numeral  38 .  FIG. 14  shows the bottom end portion  24  of a ski pole  18  having a ski pole disc  38  secured thereto. The ski pole disc  38  in  FIGS. 14 and 15  is intended to provide an imprinted image in a snow surface that includes both a text portion and a pictorial portion. In this instance, the pictorial portion of the image is formed by recesses  40  of the ski pole disc  38  outlined by circumferential edge  34  that depicts the head of a horse. The text portion of the image is formed by other recesses  42  in the ski pole disc bottom surface that form the imprint of letters in the snow surface, and in this case the letters form the word “BRONCOS.” The ski pole disc  38  of this embodiment also may include the illumination and/or sound features discussed above.  
      The ski pole disc of  FIGS. 14 and 15  demonstrates how the bottom contoured surface of the ski pole disc can employ both text portions and pictorial portions to provide an image indicative of an athletic team, such as a logo. This embodiment further illustrates that the top surface of the disc also may be used to impart information. For example, the “BRONCOS” logo on the top surface will be visible to others as the skier is waiting in a lift line or using a chair lift to reach the top of the ski slope. In one embodiment, only the top surface of the disc is configured to impart information.  
      Ski pole discs can be secured to the bottom end of ski poles in a number of ways. For example, the disc may have a central opening  44  therethrough that receives the bottom end portion  24  of a ski pole  18 . The ski pole  18  may be tapered, and the disc opening  44  may have a corresponding taper, so that when the bottom end of a ski pole is inserted into the ski pole disc, the ski pole disc is held in place by frictional engagement.  FIG. 15  shows the bottom end portion  24  of a ski pole extending through the ski pole disc  38  and through opening  44  therein, with the bottom end  46  of the ski pole extending beyond the bottom surface of the ski pole disc.  
      As shown in  FIG. 16 , an insert  50  may be provided that fits into the central opening  44  of the ski pole disc  38  to enable the disc to be firmly engaged with the bottom end portion  24  of the ski pole  18 . The insert  50  may be a hollow cylinder with longitudinal slots  52  at one end to provide flexibility, so that it can be inserted into the central opening  44  of the disc  38 . The ends of the insert may have circumferential rims  54  that are larger in diameter than the central opening  44  to allow the insert to lock into position in the disc  38 . Once the insert  50  is installed in the disc  38 , the bottom end portion  24  of the ski pole  18  is inserted through in the center  56  of the insert  50 . Because ski poles vary in diameter and shape, inserts of various sizes and configurations may be provided with each disc to allow the disc to be installed on a variety of different ski poles.  
      There are numerous systems for removably securing a ski pole disc  38  to the bottom end  24  of a ski pole  18 , and it is understood that the present invention can employ any known attachment method. Further, the ski pole disc of the present invention may be more or less permanently secured to the bottom end portion of ski poles, instead of being removable. However, in the preferred arrangement, the ski pole discs are designed for replaceable use in combination with ski poles, so that the owner of a set of ski poles can have more than one set of ski pole discs to selectively impart different images. The disc  38  may be removed by applying a downward force and possibly a twisting force to the disc  38  and insert  50  assembly and sliding the assembly off the bottom end  24  of the ski pole  18 .  
      The replaceable nature of the ski pole disc allows the user to periodically change the disc in accordance with the user&#39;s tastes. For example, a particular disc may be selected to mark an occasion, such as a win by a favorite sports team. As a further example, discs having advertising images may be sold to or given to skiers or may be attached to rental ski poles to encourage skiers to disseminate advertising information. Also, it may be desirable to attach discs having the illumination features only at night.  
      As noted above, the present invention includes methods of imparting information using a disc attachable to a ski pole. In certain embodiments, the disc is selected based on a configuration of a bottom surface of the disc, which forms an image in the snow that imparts information to a person viewing the formed image. Alternatively, the disc may be selected for attachment to the ski pole based on a configuration of a top surface of the disc, which imparts information to a person viewing the top surface, or based on the configuration of both the top and bottom surfaces.  
      The present invention also includes methods of advertising, in which a ski pole disc is formed having an advertising image on a bottom surface of the disc. The bottom surface is configured to impress the advertising image in the snow. The ski pole disc is provided to a user and is removably attached to a ski pole by the user. Alternatively, the ski pole disc may be formed to have an advertising image on a top surface of the disc, which is configured to impart the advertising image to a person viewing the top surface, or on both the top and bottom surfaces.