Patent Application
20060252609
The present invention generally relates to exercise equipment. More specifically, the present invention relates to safety devices used in conjunction with exercise equipment.
Exercise equipment is quickly becoming more of a part of the daily lives of people in our fast paced and yet physically sedentary lifestyle. The basic concept of resistance or strength training appears dangerous on the surface, and in some cases it is. Effective strength training must stimulate the muscles by an “overload” or by stressing the muscles to a greater degree then they are accustomed to being stressed. This typically involves using heaver weights on subsequent training sessions. As the weight increases, the potential for injury also increases. This injury may result from stressing the muscle beyond its ability to recover (overtraining) or to accommodate a specific load (muscle strain or muscle pull). These types of injuries are usually relatively minor. In these cases the body will recover within a short period. A more serious injury type is by allowing the weight to fall and impact a portion of the user's body. This can result in severe damage to the body including permanent injury or even death. In an effort to address some of these potential problems, equipment designers have come up with products that decrease the chances of injury while allowing certain movements to be performed. One such example is a “smith machine”. This machine includes an Olympic bar that allows weight plates to be received on each distal end. The bar is guided by two linear bearings or the equivalent, thus limiting the movement of the bar to one degree of freedom (substantially vertical displacement). Examples are shown of typical smith machines in the accompanied photos. The unit by LifeFitness is very standard and does not have a counterbalance to offset part of the weight of the bar. The Flex product (photo) does have a counterbalance. This allows a lighter minimum resistance for use with some exercises. The safety advantage to such a device is the linear displacement of the weighted bar. The limited freedom of movement reduces the likelihood of the bar being dropped and injuring the user.
The typical locking mechanism used includes a series of pins along the vertical rails and a pair of hooks that are mounted to the bar. The user rotates the bar to engage or disengage the hooks on the pins. When engaged, the bar hangs from the pins by way of the hooks. When disengaged, the bar is free to move, or fall. The problem is, some times the user may think the bar is hooked on the pins, when in reality it is not. The bar can be dropped and potentially severely injure the user. In other cases the user may want to engage the pins, but is not able to do so due to loosing grip with the bar, fatigue, or sustaining an injury while using the device. In each of these cases, the bar may fall and injure the user or a bystander.
The disclosed invention may also be adapted to many forms of exercise equipment and is not intended to be limited to a “smith machine” or for that matter any other linear motion device. In most cases a linear or curvilinear track is preferable and accepted in the industry. As such, these types of devices are shown for examples. Another typical device is a “hack squat” machine. Photos of typical hack squat machines from Muscle Dynamics and Hammer Strength are included for reference. These include a back support pad that is mounted to a carriage that moves relative to a base plate on which the user places their feet. The user reciprocates the movement of the carriage to exercise the muscles of the legs and hips, usually with weights added to the weight collars.
In one aspect, the invention features an exercise device including a frame supporting a track and a load rack. A lock frame supports a guide member. The guide member receives the track. A pawl shaft is articulated by a handle and the pawl shaft is received by the lock frame. A first pawl is mounted to the pawl shaft, thereby enabling selective engagement and disengagement of the first pawl with the load rack by way of the handle. A second pawl is movably mounted to the lock frame and a bias mechanism connects the first pawl to the second pawl.
The invention may also include the load rack as being a notched rack, which may be comprised of a plurality of saw-toothed notches. The track may be selected from a group including a solid shaft, a hollow tube or an open channel of virtually any shape or size. The guide member runs on the track and is a preferably a device selected from a group including a linear bearing, a bushing and a rolling element. The rolling element may include a wheel, ball bearing or a carriage roller.
The handle may be a substantially longitudinal bar that is substantially collinear with the pawl shaft. The handle may also be remote to the pawl shaft and be articulated by the handle by way of a push bar. The bias mechanism is preferably comprised of a spring. This spring may be a coil extension spring.
In one form, the device may include the load rack as being movably mounted to the frame. A base spring may be mounted to one end of the rack thereby at least partially supporting the rack on the frame and thus providing a cushion to dampen the impulse load by reducing the acceleration of a load the device would “catch”. This base spring may be comprised of a compression spring that is manufactured from a material consisting of plastic, metal, natural rubber and synthetic rubber, and preferably from polyurethane.
The second pawl is preferably counterbalanced such that, in an unattended state, the second pawl is engaged with the rack. The previously noted bias member holds the second pawl in a position disengaged from the rack.
The device may also include a bumper stop releasably mounted to the rack such that it may be movably mounted to the rack along a portion of the length of the rack, thus providing an adjustable bottom most position for travel of the lock frame. The lock frame may also include a tension member, such as a cable, connected to a counterweight so as to at least partially offset the weight of the mechanism to be lifted. Finally, the device may include a weight collar adapted to receive weight plates, the collar being mounted to the lock frame.
In another aspect, the invention includes a method of exercise providing the elements of the device as noted and including the steps of grasping the handle by a user, articulating the handle to disengage the first pawl from the rack and moving the lock frame, thereby exercising the muscles of the user. In addition, the method of using the safety lock during exercise is described and includes providing the bias member to become disconnected from either of the first pawl or the second pawl and allowing the second pawl to engage with the rack, thereby limiting movement of the lock frame in at least one direction.
The foregoing and other objects of this invention, the various features thereof, as well as the invention itself, may be more fully understood from the following description, when read together with the accompanying drawings, described:
For the most part, and as will be apparent when referring to the figures, when an item is used unchanged in more than one figure, it is identified by the same alphanumeric reference indicator in all figures.
The present invention is an exercise device 18 with a safety lock mechanism. A typical example of a device 18 in the form of a smith machine is illustrated in
A single side frame 20 that has been shortened and has structure removed to show critical aspects of the device is shown in
The rack is a toothed rack, and as shown here in the preferred embodiment, is a saw-toothed rack. This rack 34 has an intimate interaction with the first pawl 36 to restrict the movement of the lock frame 26. The use of the track here is also extended to the vertical tube 38 of the side frame 20. This is done through the use of a wheel 40 rotatably mounted to the lock frame 26. The wheel 40 rolls against the side of the vertical tube 38 closest to the lock frame 26, and thereby restricts the side-to-side movement of the lock frame 26. Additional wheels 40 can be positioned adjacent to other structure such as the second vertical tube 42 to further guide the movement of the lock frame 26.
The bumper stop 30 is shown here as it would be positioned just short of contact under the lock frame 26. The bumper stop 30 includes a cushion 44 to dampen the impact in the event that the lock frame 26 experienced a collision with the bumper stop 30.
An additional feature that is not critical to the novelty of the invention, but can be desirable is the use of a counterweight 46. The counterweight 46 is connected to the lock frame 26 by way of a tensile element, here a cable 48. Two pulleys 50 redirect the cable 48 to allow the counterweight 46 to offset some or all of the weight of the lock frame 26, internal components, handle bar 24 and weight collar 28. Rods 52 mounted to the side frame 20 guide the counterweight 46.
Additional detail is shown in
The pawl shaft 54 is received by the lock frame 26 and mounted to the first pawl 36 located therein. The first pawl 36 is captured between the sleeves 56 and the pawl shaft 54 extends through and is pivotally supported by the lock frame 26 by way of the sleeves 56. Bearings 58 are received by the sleeves 56 to allow smooth rotation of the pawl shaft 54 within the lock frame 26, thereby enabling rotation of the first pawl 36. A clamp 60 is secured onto the distal ends of the handle bar 24 creating a boundary for the pawl shaft 54 and therefore the position of the handle bar 24 relative to the lock frame 26.
A base spring 62 is located on one end of the linear component 22. The base spring 62 is preferably mounted to the bottom end of the linear component 22. A spring plate 64 captures the base spring 62, thereby maintaining its side-to-side position on the frame 20. Two fasteners 66 are used to secure the plate 64 to the frame 20. The front to back position is maintained by a base structure 68, which has been adapted to limit the movement in this direction. The combination allows a boundary for the linear component 22 to move without over constraining the structure. This allows for more relaxed tolerances in manufacturing thus reducing costs and assembly problems. The function of the base spring 62 is to allow the linear component 22 to move vertically when a load is placed on the rack 34. This cushion dampens the load, thus reducing the stress on the rack 34 and pawl 36 when a heavy weight is applied rapidly, such as when the handle bar 24 is dropped while in use.
A portion of one side frame 20 with one side of the lock frame 26 removed to show the internal structure, is shown in
The bias spring 82 has a second purpose of biasing the first pawl 36 into engagement with the rack 34. This means that if the user releases the handle bar 24 for any reason, the spring 36 will cause the first pawl 36 to rotate into the rack 34 automatically, thus engaging the lock. As the pawl engages the teeth of the rack 34, the lock frame 26 and handle 24 are prevented from moving in one direction, down.
In this figure the first pawl 36 is engaged (locked) with the rack 34 and the second pawl 72 is not engaged (unlocked). For the purposes of this disclosure, the term “locked” will refer to the engagement of a pawl with the teeth of the rack 34, even though upward movement is still allowed. The term “unlocked” will mean that the pawl is not engaged with the rack 34. As noted, the saw-tooth design on the teeth of the rack 34 allows the pawls to engage the rack 34 to limit the downward movement but still allow upward movement. This has several advantages. First, if a spring breaks and the second pawl engages or if the user releases the handle bar 24 for any reason, the user's contact with the device (here the handle bar 24) will not experience an uncomfortable stop, such as running into a wall. The bar 24 is allowed to continue its upward movement but will not fall. The greater potential for injury would be a result of the fall, which is eliminated by the lock. In addition, many athletes desire to train by doing heavy explosive throwing movements. Jumping is throwing the body into the air and Olympic weight lifting is throwing the weighted bar into the air. The potential for injury occurs when the athlete must catch the thrown weight. Here the device catches the weight, removing that potential for injury to the athlete.
When the handle bar 24 is rotated as indicated by the arrow 84, the first pawl 36 is rotated away from the rack 34 as is shown in
The first pawl 36 has an upper stop plate 86 to limit the movement of the first pawl 36 and thereby limiting the rotation of the handle bar 24. This is done to increase the security of the grip of the user on the bar 24 and just as importantly, to prevent the spring 82 from over extending. In
A broken spring 82 is illustrated in
A side view of a shortened version of a side frame 20 is shown in
With one pawl engaged with the rack 34, the weight of the mechanism, handle bar and more importantly any weight plate, is transferred through the pawl 36 to the rack 34 and to the bottom of the frame 20. If the weight is dropped this impulse to the tooth of the rack 34 can be substantial given a potentially high acceleration of stopping the weight from falling. The acceleration is educed by allowing a cushioned support of the rack 34 on the frame 20 in the form of the base spring 62. This can significantly reduce stress on the mechanism. In order for this to be effective, the rack 34 must be allowed to move vertically a small amount. This is accomplished by providing an upper plate 92 on the top portion of the linear component 22 with holes to receive shoulder bolts 94 that are fastened to the upper portion of the side frame 20 by locknuts 96. The shoulder of the shoulder bolt 94 acts as a guide to allow some vertical movement of the rack 34 when the base spring 62 is compressed under load. This is also illustrated in an isometric view in
The bumper stop 30 is also shown in this view in its preferred embodiment. In this form the bumper stop 30 has a pawl tip 98 that is selectively engaged with a tooth of the rack 34. The cushion 44 is used to dampen the impact of a dropped load in a manner similar to that described for the base spring 62. The cushion 44 is mounted to the top plate 100, which includes an attachment hook 102 to secure it to the linear component 22. A back plate 104 rests against the first vertical tube 38. When a high load is applied to the bumper stop 30, the moment created to rotate the stop 30 (clockwise in this view) is countered by the reaction forces by both the attachment hooks 102 against the vertical component 22 and the back plate against the tube 38. The combination of both structures (102 and 104) to distribute the load greatly increases the strength of the stop 30.
The adjustment of the bumper stop 30 is illustrated in
An alternative form of the invention is shown in
An elevated side view of the machine 106 with the seat back 108 removed and a portion of the lock frame 26 removed is shown in
This version of the invention may also utilize the cushioned effect of the track (frame tube 112) on the frame. This is accomplished by a base spring 62, this time in a circular shape, which is received by a base cup 128 secured to the base 130 of the frame 114. The linear movement of the frame tube 112 is provided by a support tube 132 mounted to the rear frame members 134. The frame tubes 112 include a pair of ears 136, which support a shaft (not seen) received by the support tube 132. This allows for displacement of the frame tube 112 relative to the base 130, thereby enabling the base spring 62 to cushion a high impact load.
An isometric partial view of the hack squat 106 is shown in
In
The invention as shown and described herein is the preferred embodiment of the invention as seen by the inventor. It is understood that an infinite number of variations of certain details are possible and therefore are inherently included in this disclosure.
