Abstract:
A training system and method for a football blocking sled having a plurality of vertically extending, laterally spaced apart pads supported on a base. At least one sensor is provided for each pad and a communications link is provided from each sensor to a control and display device. A player is positioned in front of each pad, and a common start signal is generated, prompting the players to simultaneously contact the respective pads. The sensors measure the elapsed time between the prompt signal and the respective contacts. The device displays a figure of merit commensurate with the measured elapsed times, indicating deviation from simultaneous contact. In a preferred embodiment, differences of impact force and blocking power among players can also be displayed.

Description:
BACKGROUND 
       [0001]    For many decades, so-called blocking and tackling sleds comprising at least one spring-loaded pad have been used on football practice fields, to improve the performance of the players, especially linemen. 
         [0002]    A team may have up to eleven players on the field at any time. Offensive formations generally have seven linemen, aligned within one yard of the football, and four backs located more than a yard from the football. A straight line drawn through the nose of the football perpendicular to the length of the field is generally referred to as the “line of scrimmage”. 
         [0003]    The linemen can be spaced laterally in a variety of ways, but generally the middle lineman or “center” crouches over the ball and at least two linemen on either side of the center (the interior linemen) all crouch collectively along the line of scrimmage. Once the linemen are set in their stance, no movement is permissible until the ball is “hiked”, i.e., delivered from the center to a back. 
       SUMMARY 
       [0004]    It is an object of the present invention to provide a training apparatus and method by which linemen, especially offensive linemen, can learn to quickly and uniformly coordinate their initial movement off the line of scrimmage, from a start cue associated with hiking of the ball. 
         [0005]    This object is achieved by providing sensors on each pad target of the blocking sled, with associated measuring and display devices, whereby the coach can initiate a start cue and determine, on an individual basis, the time interval between the start signal and contact or impact by each player against the pad. In addition, the same or separate sensors can be provided to measure the force and duration of contact with the pad. 
         [0006]    In one aspect, the invention is directed to a football sled with a plurality of pads and a sensor associated with each pad for generating a data signal indicative of a time dependent figure of merit associated with contact between each player and a respective pad. A display device receives the signals and compares them to a reference timeline or to each other in real time for immediate display to the coach. 
         [0007]    From another aspect, the invention is directed to a kit having sensors which can be attached to the pads on the sled, and a display device which communicates with the sensors and, based on the measurements derived from the sensors, records or displays information commensurate with time dependent contact between the players and the pads. 
         [0008]    From yet a third aspect, the invention is directed to a method of training football players using a sled having a plurality of pads supported on a base, whereby sensors on the pads communicate impact-related data to a display device. A plurality of players are positioned in front of the respective plurality of pads and, at the coach&#39;s prompting, the players block or tackle the respective pads. The sensors measure the elapsed time between the prompt and the respective contact and this measurement is used in the display device to indicate a difference in the measured elapsed time among the players. 
         [0009]    The invention provides many options for the coach to make comparisons among players who are prompted to contact the sled simultaneously, or to measure the performance of individual players who are prompted to contact one or more pads with multiple hits. 
         [0010]    By combining measurements of force and time, an indication of overall power can be obtained and compared among the players. The measurement can be for a specific time interval, such as overall power delivered during three seconds, or total power delivered over the entire length of time that the players maintains contact with the pad before slipping off. This would be indicative of the ability of each player to follow through after initial contact with an opposing player and continue vigorous leg drive so as not to lose the opponent. Alternatively, the time measurement could remain open, whereby the coach could obtain an indication of the stamina of each player by a figure of merit which reflects the force applied to the pad until the player reaches exhaustion. 
         [0011]    Another alternative is for the lineman to be prompted with a “hike”, contact the pad with an impact force, and then return to a stance. The coach could repeat this many times, in cycles of stance, impact, return to stance, impact, and return to stance, with the display and/or recording of a figure of merit for each player showing the change in the timing and the force of impact during the course of the drill. 
         [0012]    A sled with multiple pads can also be used to assess characteristics of individual players. For example, a player starts at one end of the sled in front of a first pad. At a prompt, the player impacts the first pad, backs off, goes into a stance in front of the second pad, impacts the second pad, backs off and assumes a stance in front of the third pad, and continues this sequence through impact with the last (typically seventh) pad on the sled. The measurements at each pad would enable the coach to record how quickly the player was hitting the pads, and whether the player was losing any strength or force as he moved from pad to pad. 
         [0013]    In yet another exercise for an individual player, primarily defensive lineman, he assumes a stance in front of the first pad, hits the first pad, recoils off the first pad, rolls laterally along the ground and then assumes a stance in front of the third pad, hits the third pad, recoils, rolls, comes up into a stance, hits the next pad, and continues the sequence until the seventh pad is hit. This exercise would test the force and the stamina of the player to execute defensive moves. 
         [0014]    It should thus be appreciated that the invention is well suited to providing objective data for a coach to continually improve the timing, coordination, and sustained forceful contact of an offensive line, and to identify relative weaknesses in individual offensive and defensive linemen. The relatively slower or weaker player can then be given a dedicated strengthening or practice routine. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0015]      FIG. 1  is a schematic representation of a seven man blocking or tackling sled used during football practice, configured with sensors and display and control device, according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]      FIG. 1  shows a seven man blocking sled  10 , with individual blocking pads  12   a - 12   g.  Each pad is mounted on a sled frame  14 , which includes base portion  16  resting on the ground or turf and extending longitudinally in a first direction, and a post  18  extending vertically from the base for supporting the respective laterally spaced pads  12 . The posts can be in the form of stiff cantilever or leaf springs that bend in proportion to the deflection force applied on the pads. Each combination of pad  12  and post  18  can be considered a target. It should be appreciated that in  FIG. 1 , the back side of the sled is shown. The linemen would take their positions behind the pads and upon the start signal accelerate into impact with a respective pad and collectively push the sled in a second direction perpendicular to the first direction (i.e., upwardly from the plane of the drawing sheet). Typically, one or more coaches would stand on the sled to both increase the weight and be closer to the impact or contact between the players and the pads. 
         [0017]    According to one aspect of the invention, a sensor  20  is associated with each target and with a communications pathway  22  whereby a time, force, or similar impulse signal is transmitted and preferably collected as shown at  24 , for ultimate delivery  26  to a display unit  28 . The display unit has up to seven display windows or the like indicated at  30 , which show a given figure of merit associated with the respective seven sensors  20 . The display device  28  can include control features, such as a series of switches for selective generation of mode of operation or a start cue. Only three switches  32 ,  34 , and  36  are shown, but it should be appreciated that any number of switches can be utilized, or one switch or button that toggles or sequences through various selections can be used. 
         [0018]    As an example, a pod  38  is shown at the base of the post for the center pad  12   d,  as a proxy for the football to be hiked by the center. The coach can select with switch  32 , whether the pod  38  will function as a microphone or speaker which will receive or deliver a timing start signal to the display device  28  when the coach standing on the sled or the coach or quarterback behind the linemen, shouts or actuates an audible “hike” or equivalent. Alternatively, the pod  38  can include a light source controlled by the coach at the display device, or the pod could be adapted to cradle a football and include a switch that initiates the clock timer when the center actually moves the ball with a “hiking” motion. Alternatively, the microphone and/or speaker can be in the display device  28 . 
         [0019]    It can be appreciated that with routine electronics, conventionally available, any of the initiating cues can start a clock and the delay time between that start and the receipt of a pulse from each of the sensors  20  can be compared and the individual time differences associated with each pad can be displayed on the respective windows  30 . 
         [0020]    It should be understood that  FIG. 1  is quite schematic in that the display device could be mounted in a resilient frame or the like on the sled, such as the center post, with the communication paths  22 ,  24 ,  26  in the form of wires supported on the frame. Current wireless technologies such as Bluetooth, can provide an alternative, whereby hardwiring on the sled is not required and the display device can either be mounted on the sled or carried in the coach&#39;s hand, with the coach standing on the sled or behind the linemen, or at the side, viewing the linemen along the line of scrimmage. 
         [0021]    With the same or different sensor  20 , and an optional switch or change in switch  34 , the impact force of the linemen on the pad can also be measured and the differences among the linemen indicated. With yet another option according to switch position  36 , an indication of power (i.e., force integrated over a period of time) can also be measured individually. Moreover, the time delay to contact, the initial contact force, and the time dependent delivery of power could be shown in a separate display, or stored for later downloading or printing. 
         [0022]    Persons of ordinary skill in the field of measurement and display devices can readily implement the functionality described with respect to  FIG. 1 . A non-limiting example of one form of pad, associated support, and sensor is shown in U.S. Pat. No. 4,573,680, particularly  FIG. 2 . U.S. Pat. No. 6,093,119 shows how measuring and signaling elements can be connected to force transferring members. The disclosures of the &#39;680 and &#39;119 patents are incorporated herein by reference. 
         [0023]    Although  FIG. 1  shows a schematic of the inventive concept as may be implemented on a blocking sled, it should be understood that the combination of sensors  20 , communication channels  22 ,  24  and  26 , and display device  28  (with or without pod  38 ) are considered novel apart from combination with the sled. In a portable system, the sensors  20  would include some form of mounting device, the simplest of which would be a strap as indicated in  40 , which wraps and attaches to itself or is otherwise secured to the pad  12  or post  18 . An alternative would be a hook and loop combination between the pad and the sensor (e.g., Velcro), strong enough to withstand vigorous impact against the pads. The mounting of the sensors on the pads for use only in determining the time difference among the linemen when impacting the respective pads, need not be specially designed because the only significant measurement is initial movement of the pad or sensor. 
         [0024]    On the other hand, if sustained contact, impact force, or power is to be measured, the sensors would need to be mounted securely and uniformly on each pad. The simplest could include a spring or the like that has a known relationship between force and deflection and a sensor for measuring the duration of the deflection. As noted previously, the sensor and associated transducer and transmitter could be set up for wireless communication with the display device (as well as the pod  38  when present), in which case the system would consist essentially of the display device  28  and sensors  20 . 
         [0025]    Preferably, a single, composite sensor or discrete sensors (such as  20  and  42 ) are provided at each target for sensing all of moment of impact, force of impact, and duration of contact. In  FIG. 1 , a sensor  20  is mounted on each pad to sense movement of the pad or sensor from a stationary condition, thereby generating a data signal at the moment of impact. Another sensor  42  is permanently or temporarily attached to the post via strap or the like  44  for generating a data signal commensurate with impact force. Mounting of this sensor on the post avoids the uncertainties associated with compaction of the pads during time-dependent impact on the pads. Although not shown, sensors mounted elsewhere on the frame could be used, such as a laser associated with each target with a beam or beams that are directed parallel to the base  16  in the first direction and respond continually to the displacement of the pad or post in the perpendicular second direction. 
         [0026]    The display device includes a time counter that can be started when the hike cue or similar start signal is transmitted to a plurality of players vocally or by a component of the system, while the players are in a stance spaced from a respective plurality of pads. One figure of merit is the time interval between the start signal and the data signal generated by movement of the target the moment each player impacts the respective pad. Another figure of merit is the force of impact by each player on the respective pad, and yet another is the time-dependent force during sustained impact on the respective pads. 
         [0027]    It should be appreciated that, although a standard front line sled has seven targets, the invention can effectively be implemented with a sled having five targets representing so-called “interior linemen”. 
         [0028]    The stand-alone training kit aspect of the invention can be purchased by a coach or team sponsor for use as an aftermarket improvement for sleds that are already in use. Such kit should have sensors, a control and display device, and associated data communications capability for seven targets. A plurality of sensors are mountable on a respective plurality of targets, each sensor of the type that generates a data signal when the target is displaced from a stationary condition. The display device is receptive to each of the plurality of generated signals, which for determining a timing figure of merit are ideally generated simultaneously if the linemen are perfectly coordinated at impact. For present purposes, “substantially simultaneously” should be understood as within less than one second. However, the data processing within the display device need not generate the display to the coach within one second. For coaching purposes, “real time” display can be considered as within about 15 seconds of the moment the players hit the targets. 
         [0029]    Preferably the training kit includes a first set of at least five sensors with straps or other fasteners for mounting on a respective at least five targets, with each sensor of a type that generates a first data signal when the target is displaced from a stationary position. A second set of at least five sensors are mountable on a respective at least five targets, with each sensor of a type that generates a second data signal commensurate with the force applied to the target. The display device includes a time counter that can be started when a start signal is transmitted to the players while they are spaced from the targets. The display device selectively displays a plurality of figures of merit, including a time interval between the start signal and the moment each player impacts the respective pad, the force of impact by each player on the respective pad, and time-dependent force during sustained impact on the respective pads. 
         [0030]    The display can provide a value for the impact related condition of each target, and optionally a comparison among the players based on the differences in the values produced from each target. The display device preferably has a digital memory where the values are stored, with a USB port or other data transfer technique whereby the coach can transfer performance data to a workstation or the like where detailed trends and analyses can be performed for individual players and various combinations of players constituted as an offensive line. 
         [0031]    The signal processing associated with converting an impact pulse or the like to an electronically displayed figure of merit, requires several straight-forward steps of digital processing. It is well within the skill of ordinary programmers to determine which of the processing steps should be performed at the sensors  20  and  42  (and associated transducer and signal generator) and which are to be performed in the display device  28 .