Abstract:
This is an automatic locking exercise device that incorporates a one-way locking mechanism. The device includes a frame, which supports a track, preferably a pair of linear bearing rods one on each side. A guide member, or linear bearing runs on each bearing rod and is attached to a handle or bar that is grasped by a user. A one-way lock is used to provide movement of the bar along the track in an upward direction but opposes movement down. In the preferred embodiment, rotating the bar actuates a lock release. This disengages the one-way lock and enables the bar to move freely up and down along the track. If the user ever drops the weight the one-way lock automatically engages and catches the weight. Explosive power training can also be performed on the device in that the user can safely throw the weight, knowing that the weight will be automatically caught at its highest point without risk of injuring someone. Marking the highest point allows the user to quantify their explosive training performance and progress.

Description:
BACKGROUND OF THE INVENTION 
     The invention herein relates to exercise devices and more particularly to an exercise device with an automatic locking feature that allows for explosive power training. 
     Exercise devices have a singular function, which is to stress the body in a controlled manner. This control provides an element of safety that is intended to prevent injury. In some cases this “control” takes away from the function of the exercises performed on the device. When properly designed, an exercise device allows additional features that are not possible or feasible do to safely of the user or the surroundings. Many restricted motion, such as linear motion, exercise devices fall under one or both categories. 
     Exercise devices that follow a track are typically linear in nature, but can be curvilinear or arcuate. They are generally supported on a frame and have a bar or carriage that is attached to linear bearings or wheels. These bearings or wheels run on a rod or in tracks, which are supported by the frame. Typically, movement is restricted to a single degree of freedom, as is the case with a linear motion device. These devices can be potentially limiting, in the case of mimicking a movement that is not typically linear in nature. A bicep curl for example would not be an easily adapted exercise to a linear device, but a back squat would, in that the bar moves in a substantially linear motion anyway. 
     Since the movement is restricted by the track and frame, if the user fatigues to a point that they are put in danger of being injured by the weight falling on them, some method of catching the weight can be employed. Unfortunately in most products this is limited to two or more catches in which the user must move some lever or rotate the bar and find the hook at the same time. Though better than nothing, doing a bench press and realizing you do not have the ability to stop the weight before it hits your chest, looking for a lever and a hook a fraction of a second before you are trapped, is far from optimal. In addition, if the weight slips from your grip, or the weight must be dropped due to an injury, the “finding a hook” process is not an option since your hands may no longer be on the bar or handle. 
     Research has given evidence to support the adage “train as you perform”. Many athletes rely on explosive power production (work done over time) to optimally perform their athletic events. Jumpers, throwers, sprinters or any other use of rapid acceleration of their body or another object, is a power athlete. Newton and colleagues, at Southern Cross University in Lismore, Australia ( J. Appl. Biomech.,  1996, 12: 31-41) found a greater velocity of movement, force production and muscle activation in subjects that were allowed to release the bar at the end of a bench press movement versus the same movement with the exception that the users held on to the bar at the end of the movement. The “throwing” movement is consistent with what is seen in sport and also lends itself to consistent neuro-muscular adaptation, which is another positive training feature. Without a specific device, the risks to such a method of training are obvious. Throwing a weighted bar is dangerous to the user and anything in the vicinity when the bar comes back down. Also it is difficult, if not impossible, to gauge the performance of such throws or in this case to mark the height of the throw. Though a linear, or restricted, motion device was used in this study, it has been expressed to the applicant that such a device was specifically modified for use in this study. It included an electromagnetic brake that was actuated manually by the test administrator or by the sensing devices and controlled by a microprocessor. 
     Few if any real attempts have been made to enable such training or providing a device which allows a safer method of general physical training. Hibler, Jr. et al (U.S. Pat. No. 4,549,734) discloses a leg press device that includes a seat pad position locking device which has a rail with slots cut therein and a pivoting handle with angular placed “dogs” secured thereto. This “ratcheting” device is used specifically as a seat adjustment. It is not associated with the carriage where the weight is positioned and therefore has nothing to do with securing the weight. 
     SUMMARY OF THE INVENTION 
     Present Invention: 
     In one aspect, the invention features a frame with a load rack and a track. The track is typically a linear bearing rod or a channel, which may be substantially linear, curvilinear or arcuate. A bearing member, such as a linear bearing, bushing or a wheel, is used in communication with the track. The bearing member is attached to a handle, such as a longitudinal bar. The device also includes a one-way locking mechanism. This lock includes a counterbalanced eccentric pin, which is secured to the handle. The eccentric pin provides contact with the load rack while in an unattended state and detachment from the load rack when the handle is rotated. The counterbalanced of the eccentric pin is either due to the force of gravity acting on the pin, thereby applying a force to move a pin tip into contact with the load rack, by use of a spring or both. 
     The system may also include a load rack that is comprised of a notched rack, preferably a saw-tooth notched rack, or a pressure plate. The pressure plate includes a substantially flat plate with a relatively high coefficient of static friction between an outer surface and a contact surface of the eccentric pin. Additional features include the load rack being movably mounted to said frame and a rack spring that at least partially supports the load rack on the frame. 
     In another aspects, the invention includes a method of providing an exercise device, which includes moving the handle upward, by a user, in a forceful manner and releasing the handle from contact with the user and then allowing the locking device to secure the handle when the handle is free from contact with the user. This allows the user to perform explosive movements by throwing the weight. It also allows the user to drop the weight without risk of injury. 
     Definition of Terms: 
     Unless otherwise defined, all technical and scientific terms used herein have the same intended meaning as would be commonly understood by anyone of ordinary skill in the art to which this invention belongs. To eliminate possible ambiguity, specific terms used herein have been defined, as they would be applied to the present invention. 
     The term “curvilinear” relates to any thing having a shape of a curved line, or any portion of or combination of curved lines. For example the shape of an “S” is curvilinear in that it includes a combination of curved lines and straight lines. 
     The term “arcuate” relates to any thing having an arced shape, which includes a bend or curve in the form of a bow. This may be a single formed curve that is made up of a variety of small curves of various radii that are all joined together end to end. 
     The term “linear” relates to any thing that is straight, not being curvilinear or arcuate. “Substantially linear” is considered to include structures that are linear within reasonable manufacturing processes. 
     The term “compression spring” includes any form of bumper or coiled spring. This includes natural and synthetic rubber bumper stops, coiled springs, Belleville spring washers, curved spring washers, wave spring washers and gas springs. 
     The term “eccentric pin” will be used as a generic term to include both the terms “cam” and “pawl”. These terms are both used in this application to designate an eccentrically shaped device that articulates with a rack or plate to lock one to the other in one direction but allows free movement in the opposite direction. The term “cam” is typically used in relation to a friction lock and “pawl” is used in conjunction with a toothed rack. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric, exploded view of a linear motion exercise device produced in accordance with a preferred embodiment of the present invention. 
     FIG. 2 is a side view of an assembled linear motion exercise device showing the relevant hidden lines, the device produced in accordance with a preferred embodiment of the present invention. 
     FIG. 3 is a top view of a linear motion exercise device, shown with the top brace removed, the device produced in accordance with a preferred embodiment of the present invention. 
     FIG. 4 is a fragmented top view of the left portion of the bar and locking mechanism of a linear motion exercise device produced in accordance with a preferred embodiment of the present invention. 
     FIGS. 5 a  and  5   b  are fragmented top and front view of the left portion of the bar and collar frame of a linear motion exercise device produced in accordance with a preferred embodiment of the present invention. 
     FIG. 6 is an exploded isometric view of a locking mechanism, including the locking pin and collar frame the device produced in accordance with a preferred embodiment of the present invention. 
     FIGS. 7 a  and  7   b  are side and associated top view, with section line  7 — 7 , of the locking mechanism in a locked position of a linear motion exercise device, the device produced in accordance with a preferred embodiment of the present invention. 
     FIGS. 8 a  and  8   b  are side and associated top view, with section line  8 — 8 , of the locking mechanism in an unlocked position of a linear motion exercise device, the device produced in accordance with a preferred embodiment of the present invention. 
     FIG. 9 is an isometric fragmented view of the bar and locking mechanism showing the rack cushion near the base of the frame of a linear motion exercise device produced in accordance with the preferred embodiment of the present invention. 
     FIG. 10 is an isometric fragmented view of the bar and locking mechanism showing the bearings and bearing rod near the base of the frame of a linear motion exercise device produced in accordance with the preferred embodiment of the present invention. 
     FIG. 11 is isometric fragmented view of the bar and locking mechanism as viewed from the inside looking out and showing a detail of an indexing marker, the device produced in accordance with the preferred embodiment of the present invention. 
     FIGS. 12 a  and  12   b  are side and associated top view, with section line  12 — 12 , showing an alternative locking and guide mechanism of a linear motion exercise device, the locking mechanism in a locked position. 
     FIGS. 13 a  and  13   b  are side and associated top view, with section line  13 — 13 , showing an alternative locking and guide mechanism of a linear motion exercise device, the locking mechanism in an unlocked position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The object of the disclosed invention is to provide an improved device and method of moving a weighted handle or bar for physical exercise. The device includes an automatic one-way locking mechanism that is engaged unless intentionally disengaged by the user. The lock allows for upward movement but not downward movement unless the lock is disengaged. When the user is not in contact with the handle or bar of the device, the locking mechanism is engaged. 
     What is shown in FIG. 1 is an isometric view of an automatic locking exercise device  12 . The device includes two towers  14 . Each tower  14  is comprised of a rear rail  16  and a front rail  18 , one on each base frame  20 . The base frames  20  are connected by cross frames  22  in the front and rear of the device. A top brace  24  is used to support the upper ends of the towers  14  as well as to capture the locking bar  26  within the framework of the device, when assembled for use. Fasteners  28  are used to secure the top brace  24  to the upper ends of the rear rails  16  and the front rails  18  of each tower  14 . The structure of the top brace  24  maintains the proper distance between each tower  14  as well as the proper distance between the upper ends of the rear rail  16  and the front rail  18  of each tower  14 . Side braces  30  are also used to maintain the distance between the rear rail  16  and the front rail  18  of each tower  14  at intervals along the span of each tower  14 . What is shown here is one example of a design, but the details of this structural design are not considered critical to the novelty of the invention. 
     A side view of the device is shown in FIG.  2 . Here the rear rail  16  and the front rail  18  that make up the tower  14  are shown in more detail. The collar frame  32  portion of the locking bar  26  is supported to frame of the device  12  by use of the linear bearings  34 . Linear bearings are the preferred method for a linear system, but a bushing can also be used. The top brace  24 , shown here as mounted to the upper end of the towers  14 , completes the assembly of the device  12 . The hidden lines show more detail of the bearing rod  36  as being supported by a series of rod supports  38  which in turn are secured to the front rail  18 . On the opposite side of the tower  14 , a rack  40  is mounted to the rear rail  16 . More detail to this arrangement is shown in the figures that follow. 
     Another overview is shown in FIG.  3 . This is a top view of the device  12 . The top brace  24  has been removed to show more detail of the device  12 . The side braces  30  supported on the base frames  20  which are in turn held together by the cross frames  22 . Each tower  14  receives a portion of the locking bar  26 . The locking bar  26  is comprised of a substantially longitudinal bar  42  preferably with a collar  44  on each distal end. The collar  44  is used to support weight plates. Generally circular in shape, the collar  44  is preferably a cylindrical tube that is made to fit standard weight plates. The rear rails  16  and the front rails  18  of the towers  14  house the locking mechanism of the locking bar  26  as well as guide it in a predetermined path of travel, in this case a linear vertical movement. 
     A more detailed view of the left portion of the locking bar  26  and a tower  14  is shown in FIG.  4 . The rest of the frame is not shown for illustrative purposes. The collar frame  32  provides a structure that supports the collar  44 . The collar frame also supports the medial collar  46  which receives the bar  42 . The bar  42  is free to move within the medial collar  46  and is preferably assisted by a bushing  48 . There is a gap between the inside edge of the collar  44  and the outside of the medial collar  46 . This gap allows for an eccentric pin or in this case a pawl  50 , which is then secured to the bar  42 . By securing this pawl  50  to the bar  42  between the collar  44  and the medial collar  46 , this secures the bar  42  relative to the collar frame  32  and allows remote articulation of the pawl  50  by rotation of the bar  42 . The front rail  18  supports the rod supports  38 , which support the bearing rod  36 . The bearing members, or in this case linear bearings  34 , are fastened to one side of the collar frame  32 , thus providing guided tracking of the locking bar  26  along the bearing rod  36 . 
     The pawl  50  is positioned to enable communication with the rack  40 , which is fastened to the rear rail  16 . Additional guides  52  are positioned on either side of the rack  40  and the pawl  50  to ensure communication between the pawl  50  and the rack  40  as well as to provide additional structural support to the rear rail  16 . In the preferred embodiment the rack  40  is secured to the rear rail  16  in a movable manner. In this case the rack  40  is secured by shoulder screws  54 , which pass through slots in the rear rail  16 . This allows the rack  40  to move slightly in a vertical direction with respect to the rear rail  16 . This movement will be later shown to be beneficial in the reduction of the peak forces during the impulse, which is experienced when the pawl  50  contacts the rack  40  under heavily loaded conditions. 
     Front and top views of a fragmented portion of the locking bar  26  and the collar frame  32 , with the pawl  50 , are shown in FIG.  5 . The bar  42 , collar  44  and collar frame  32  are as previously disclosed. The front view of the collar frame  32  shows more detail of the structure and function. As in the previous figure, the linear bearings were mounted to the collar frame  32 . This can be accomplished by any number of methods but a very functional method is, as shown here, by using several mounting holes  56 . To increase structural integrity, a series of bars are added. A top bar  58  connects the sides of the collar frame  32  on the inside of the structure. The placement of the top bar  58  is desirable in that it also has the function of supporting a pin spring  60 . The pin spring  60  is a form of a counterbalance that is preferred, in that it not only adds to the rotational torque used to rotate the pawl  50 , but it acts as a bias and damps vibration that can be experienced under extreme conditions of use of the device. The spring  60  is not necessary, but in many cases desirable. Additional sidebars  62  and lower bar  64  are also added to increase the structural integrity of the collar frame  32 . These bars are not considered necessary to the novelty of the invention but are added in that they are part of the preferred embodiment. 
     An exploded isometric, fragmented view of the collar is shown in FIG.  6 . This explicitly shows the construction of the device in the preferred embodiment, but without the pin spring. The locking pin or pawl  50  has been removed from the space between the medial collar  46  and the collar  44  and also between the top bar  58  and the lower bar  64  of the collar frame  32 . Both the medial collar  46  and the collar  44  are secured to the walls of the collar frame  32  and thereby provide support for the turned end  65  of the bar  42  when it is inserted in the medial collar  46 . The turned end  65  is fastened to the pawl  50 , in the assembled position, to enable movement of the pawl by rotation of the bar  42 . The linear bearings  34  are also shown in their relative positions, though removed from the collar frame  32 . 
     A detail of the locking mechanism is shown in FIG.  7 . The top view shows a section line  6 — 6  to which this sectioned view is shown in the front view. In this figure the system is locked in that the pawl  50  is in contact with the rack  40 . Here the counterbalance of the pawl  50  is two fold. First, the center of gravity of the pawl  50  is positioned such that the force of gravity acting on the pawl  50 , when supported by the bar  42 , applies a force to move a pin tip or pawl tip  66  of the eccentric pin or pawl  50  into contact with the rack  40 . The second aspect is that of the pin spring  60 , which in this case is a tension spring, applies a moment that also rotates the pawl tip  66  toward the rack  40 , as depicted by the arrow  68 . 
     As can be seen, the rack  40  includes a plurality of teeth that are saw-tooth notches  70 . These notches  70  include a sloped portion  72  and a load-bearing portion  74 . The sloped portion  72  provides a transition to allow the pawl  50  to move upward as the pawl tip  66  would index from one load-bearing portion  74  to the next higher load-bearing portion  74 . The pawl  50  cannot move down the rack  40  unless the pawl  50  is rotated clear of the rack  40 . This is one method of providing a one-way lock that is desirable to such a device. In this way the weighted locking bar can be moved up the rack  40  and be released from contact by the user. The locking bar is free to move up but not down, when locked, thereby providing a safety feature to the user and allowing for explosive movements for the locking bar and associated weights to be thrown. The locking bar then secures the bar at the uppermost position. In addition to safety, this gives the user quantification as to the power production of that particular lift. 
     The one-way locking mechanism is shown in FIG. 8 in an unlocked position. As with the previous figure, the top view includes a section line  8 — 8  to which the sectioned view is shown in the front view. To unlock the system, the bar  42  is rotated counterclockwise, in this view, as depicted by the arrow  76 . Here a built in stop exists by a pawl leg  78  contacting the back of the collar frame  32 . To maintain the lock in this position, the bar  42  must be forcibly maintained in this rotated position. If the bar  42  is released, the forces of gravity acting on the pawl  50  and the force of the pin spring  60  rotate the pawl tip  66  into contact with the rack  40 . In this unlocked position the collar frame  32  and the rest of the locking bar can freely move both up and down along the guidance of the bearings  34 . Repetitive exercise movements can then be performed and in the case that the bar  42  is released from contact with the user, the one-way locking mechanism will automatically engage. 
     A fragmented isometric view of a lower section of one tower  14  is shown in FIG.  9 . Sections of the front rail  18  and one guide  52  are removed, thereby making the detail more visible. The collar frame  32  supports the collar  44  and the bar  42  as previously disclosed. The lower portion of the front rail  18  and rear rail  16  that comprise a tower  14  are mounted on the base frame  20 . As previously disclosed, since the rack  40  is a load bearing structure, the force transmitted through the pawl when locked, it is in may ways desirable to allow the rack  40  to move, reducing the acceleration of the weighted bar on the rack  40 . This decreases the amplitude of the impulse and associated loads. This dampening is accomplished by positioning a cushion or rack spring  80  under the rack  40 . This enables the rack spring  80  to at least partially support the rack  40  on the frame, in this case the base frame  20 . The rack spring  80  is shown here to be in the form of a compression spring or bumper pad. Suitable materials and forms of such a compression spring are numerous. Some variations in suitable types of compression springs have been defined herein. Materials for such a spring  80  include plastic, metal, natural rubber and synthetic rubber. The preferred embodiment of this spring  80  is polyurethane (synthetic rubber) of a durometer between 80 A and 95 A. The rack spring  80  is preferably fastened to a plate  82  that is fixed to the bottom of the rack  40 . This is only one method of providing this impact-absorbing feature. The spring could also be in the form of a tension spring, which supports the rack  40  from above on the upper portion of the frame. 
     In FIG. 10, more detail is shown. Here the fragmented lower section of one tower  14  is viewed from another angle. The shoulder screw  54  that mounts the rack  40  to the rear rail  16  is shown as the shaft of the screw  54  passes through the slot  84  cut in the rear rail  16 . This allows a restricted amount of vertical movement of the rack  40  with respect to the rear rail  16 . This view also shows the rod supports  38  supporting the bearing rod  36  which provide the guidance for movement by the linear bearings  34 . 
     Another useful aspect of the device in this arrangement, is in the use of a method of quantifying the performance of a user by use of an indexing device. In FIG. 11 an isometric fragmented view of a lower portion of one tower is shown. In this view the inside of the tower is shown. The bar  42  extends toward the viewer, and the user, and the collar  44  is on the outside. The indexing device is comprised of a series of increments  85  are marked in the inside of the front rail  18 . The increments  85  may be marked in accordance with the increments of the rack, if a toothed rack is used, or in any other increments. Increments of inches are used here. A marker  86  is located on the collar frame  32  as an indicator as to the relative position of the collar frame  32 , and therefore the bar  42 , to which the user moves during exercise. In this way the user can move or throw the bar  42  and associated collar frame  32 , and collar  44  with weight plates, using the one-way locking device to secure this combination at its highest point after release. In this way the user can quantify the performance of their training. The user may also simply use it as an indicator as to the relative height of the bar, or distance traveled, during repetitive lifting. 
     An alternative form of the one-way lock and track are both shown in FIG.  12 . Consistent with previously, the top view includes a section line  12 — 12 . The sectioned view is shown in the front view of the same figure. The track, which previously was a bearing rod, has been replaced with a channel  87 , which in this instance also doubles as a front rail. The linear bearings or bushings have been replaced with a pair of front wheels  88  that together define a restricted path of travel. What was previously disclosed was a linear system. This is preferable in many instances and for the purposes of this disclosure, it is considered to be the preferred embodiment. However, in some instances specific curvilinear or arcuate paths may be desirable. In that case the track can be altered to fit an infinite number of shapes. Since linear bearings and bushings are designed to work in a linear mode, such a variation as shown here would be more easily adapted to provide curvilinear or arcuate paths of travel. The channel  87  can be formed to virtually any shape and the three-wheeled structure allows for travel along such a path. 
     The front wheels are shown here to be larger than the rear wheel  90 . This is not a necessary aspect of the invention but is preferable since the rear wheel  90  acts only as a guide and support. The front wheels  88  are required to support a large load when the eccentric pin, now shown in the form of a cam  92  is forced against the load rack, which is now in the form of a pressure plate  94 , to activate the one-way lock. The pressure plate  94  is a substantially flat plate with a relatively high coefficient of static friction (greater than 0.5) between an outer surface and a surface of contact with the contact component of the one-way lock. This contact component is a pin tip or cam nose % of the eccentric pin or cam  92 . As before, the force to make contact is that of gravity acting on the cam  92  and/or the tension in the pin spring  60 . The force of this couple is depicted by the movement of the cam  92  is indicated by the arrow  98 . This is an eccentric lock that relies on the frictional force between the cam nose  96  and the pressure plate  94 . As such, the coefficient of static friction is important to the enable the lock to work without excessive normal loads that translate to forces that work to push the channel  87  and a rear channel  100  apart from one another. As with the notched rack and pawl system as previously disclosed, this friction based system also allows for vertical (one-way) movement at all times and when locked, precludes movement of the collar frame  32 , bar  42  and collar  44  in a downward direction. 
     The pressure plate  94  is preferably replaceable in that it, like the cam  92 , are both wearing parts. The pressure plate  94  can be fastened to the rear channel  100  in any number of ways that are common to the art. Here threaded fasteners  102  are used with a countersunk head so as not to interfere with the contact of the cam  92  and the pressure plate  94 . Likewise, the rear wheel  90  is in the shape of a spool so as to use the edges  104  of the pressure plate  94  as a guide for the rear wheel  90 . Any number of modifications can be made to provide tracking on the front wheels  88  and the channel  87  as well. 
     A similar set of drawings are shown in FIG. 13, including the section line  13 — 13  in the top view and the appropriate sectioned view in the front view, in which case the lock mechanism is in an unlocked condition. The cam nose  96  is shown to be moved away from the pressure plate  94 , thus allowing the collar frame  32 , bar  42 , and collar  44  combination to freely move along the channel  87 . The arrow  106  notes the rotation of the blunt nose pawl  92  to place it in an unlocked condition. As before, this is actuated by rotation of the bar  42  by the user and must be maintained in order to remain unlocked. 
     The rotation of the bar  42  as a release lock is the preferred embodiment in that it is simple to manufacture, maintain and easy to use and understand by the user. Numerous other actuated handles of varying forms could be employed to accomplish this task. It is also considered the preferred embodiment to use of the bar  42  as the handle. In other forms the handle may not be a substantially longitudinal bar, as shown here, but a curved bar or two unique handles that act independent from each other. The pawl can also take many forms. Any device that functions as a ratcheting or eccentric locking cam with a load rack in the form of a notched rack or a pressure plate will function in this capacity. 
     It is to be understood that all of the enclosed information is presented as the preferred embodiment as seen by the inventor. An infinite number of variations and modifications can be made as the specific application arises.