Abstract:
A means and method for automatically selecting an amount of weight to be connected to a cable system in a fitness machine. When a dial is rotated to select a weight, a connected computer receives the rotational position information, operates a program to determine the amount of each weight to attach to the cable system and actuates solenoids accordingly to attach the weight to the cable by inserting pins fully into weight stacks to connect weights to a rod connected to a cable. The computer also displays the selected weight on the dial. When the new weight is selected, one or more retracting solenoids draw any inserted pins partially out before any new pins are fully inserted to connect the weights to the rod. This ensures that the system is cleared before attaching any weights to the cable.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates generally to fitness equipment, and more specifically to fitness equipment that mechanically links to one or more plates in a weight plate stack after a user selects the desired amount of weight to be lifted by the user. 
     There are various types of activities that people can engage in to enhance physical fitness. Many types of fitness devices have been invented to aid people in their quest for physical fitness, and these range from the simple barbell to the mechanically complex cable, pulley and weight stack machines. In the latter, a series of stacked weights aligned with a rod extending vertically therethrough are lifted by the user through one or more cables extending through pulleys attached at one end to the rod and at the opposite end to a handle. The user selects the position of the handle in order to correctly match the lifting routine and body size, and the user selects the amount of weight appropriate to his or her fitness level in the routine. 
     Conventional means for selecting the amount of weight include a T-shaped pin that inserts between two of the cast iron plates in the stack and into an aligned aperture in the rod. Because the pin is placed beneath one of the plates and into the rod, when the rod is raised by pulling on the cable, the weight plates above the pin are lifted with the rod. To remove the pin from the stack, one typically lowers the weights and then presses a button at the intersection of the “legs” of the “T”. This allows the pin to be withdrawn from the aperture in the rod, for example by reducing the diameter of the pin by moving radially inwardly a small ball that otherwise protrudes from the shaft of the pin. 
     While those with the ability to grasp the handle and press the button on such T-shaped pins take for granted their ability to carry out the procedure needed to withdraw such a pin, a significant portion of the population is not capable of carrying out this procedure. Fitness machines listed in the Invention Disclosure Statement have been invented to allow users who are not able to carry out this procedure to avoid such machines. However, such prior art machines suffer from various weaknesses that hinder their use. Therefore, the need exists for a fitness machine with a weight stack that permits quick and accurate change of weight and display of the selected weight. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention contemplates a method and apparatus for electromechanically selecting a specified resistance through a rotational interface used by a human operator. The preferred system components include a dial that is used to select a quantity of resistance, and also displays the quantity selected. A weight stack, or a selected portion thereof, is raised and lowered by the human user according to the quantity of resistance selected using the dial. A pin insertion assembly is actuated by a computer, using the information received from the dial in a program that is designed to mechanically link the selected weight with a cable that a human interface attaches to for lifting the weight. Preferably, a plurality of solenoids is used to drive a plurality of pins into apertures between the weights and into aligned apertures in a rod to which the cable attaches. When the dial is rotated, a system of gears engages a potentiometer to determine the specified resistance based on dial orientation. This information is processed by the computer and the computer actuates the appropriate solenoid for the selected weight. 
     The solenoids are mounted to a tower in an array of actuator solenoids and retraction solenoids. Each actuator solenoid is coupled to a corresponding array of pins through a linkage system. When an actuator solenoid is actuated by the computer, the linkage translates the corresponding pin into the weight stack to engage the weight, which enables the specified weight to travel with the cable. When a new resistance is specified by rotating the dial, the retraction solenoids are first actuated to engage a reset bar, which, through a linkage system, removes any pin engaged in the weight stack. After retraction is completed, the respective actuator solenoid is actuated by the computer according to the specified resistance. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a view in perspective of a fitness machine in which the present invention can be used. 
         FIG. 2  is a view in perspective illustrating a weight plate stack that can be used in the present invention. 
         FIG. 3  is a view in perspective illustrating a weight selection mechanism for connecting one or more weights in the weight stack with an apparatus that is lifted by cables pulled by a user. 
         FIG. 4  is an exploded view in perspective illustrating the weight selection mechanism shown in  FIG. 3 . 
         FIG. 5  is view in perspective illustrating the preferred pin insertion assembly. 
         FIG. 6  is a rear view illustrating the pin insertion assembly of  FIG. 5 . 
         FIG. 7  is a top view illustrating the pin insertion assembly of  FIG. 5 . 
         FIG. 8  is a front view illustrating a preferred weight selection dial through a sequence of movements of the dial. 
         FIG. 9  is a schematic view in perspective illustrating the preferred weight selection dial mechanism. 
     
    
    
     In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word connected or terms similar thereto are often used. They are not limited to direct connection, but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Provisional patent application Ser. No. 61/757,484, filed Jan. 28, 2013, which is the above claimed priority application, is incorporated in this application by reference. 
     The fitness machine  10  shown in  FIG. 1  is the type of device contemplated for use of the present invention. The invention is not limited to use in the machine  10  shown in  FIG. 1 , but the machine  10  is illustrated and discussed herein so that a person of ordinary skill will understand the present invention. From the description, a person of ordinary skill will know how to adapt the invention to any suitable fitness machine. 
     A weight selection mechanism  40  shown in  FIG. 3  is housed in the central housing  16  of  FIG. 1 , but is not visible in  FIG. 1 . The hand-grippable handles  12  and  14 , or some other human interface, are attached to flexible cables  12   c  and  14   c  (shown in broken lines in  FIG. 3 ), which extend through the arms  12   a  and  14   a  into the central housing  16 . The cables  12   c  and  14   c  are attached to a cable connector/pulley apparatus  20  (see  FIG. 3 ), which connects to one or more weight plates in the weight stack  30  as described in more detail below. Thus, through the cable connections, a user can pull on the handles  12  and  14 , which results in lifting of the apparatus  20 . The cable is referred to herein as a “flexible thread”, and this term is used broadly to encompass any wire rope-like structure or any structure that could replace a wire rope, including without limitation, synthetic rope, chain, flexible wire. 
     The weight selection mechanism  40  includes the weight stacks  30 ,  32  and  34  and a pair of vertical bars  42  and  44  that extend along one side of the weight stack  30  and are used for guidance during vertical displacement of the apparatus  20 . The cable connector/pulley apparatus  20  rests on the top of the weigh stack  30  and has three rods  22 ,  23  and  24  that extend downwardly from the apparatus  20  and into the weight stacks  32 ,  30  and  34 , respectively. The terms “up”, “down”, “upward”, “downward”, and other terms of orientation are used herein. These terms are relative to the position and orientation of the structures of the machine  10 , and, unless indicated otherwise, are used in relation to the orientation of the machine  10  of  FIG. 1 . If this orientation is changed, a person of ordinary skill will understand how to modify the orientation of related components. 
     The cables  12   c  and  14   c  connect the handles  12  and  14  to the apparatus  20  so that upon pulling the handles  12  and  14 , the apparatus  20  is raised from the position shown in  FIG. 3  along the vertical bars  42  and  44 . Any weights connected to the apparatus  20 , such as by pins described below, are lifted by the cables  12   c  and  14   c  when the apparatus  20  is lifted. The means by which the apparatus  20  is connected to one or more of the weights in the weight stacks  30 ,  32  and  34  will now be described. 
     The rod  23  has a plurality of apertures  23   a  formed therein (see  FIG. 4 ). When the rod  23  is inserted downwardly into the opening  23 ′ in the weight stack  30  as shown in  FIG. 3 , the apertures  23   a  align with the apertures  30   a  (see  FIG. 2 ) in the weight stack, thereby allowing a pin that is aligned with the corresponding apertures  30   a  in the weight stack to be further inserted therein through the remainder of the aligned apertures  30   a  in the weight stack and through one of the aligned apertures  23   a  in the rod  23 . Because the inserted pin connects the weight to the rod  23 , any weight plates in the stack  30  above the pin are lifted with the apparatus  20 . 
     The pin insertion assembly  60 , which is part of the weight selection mechanism  40  as shown in  FIG. 3 , is disposed at the side of the weight stack  30  where the apertures  30   a  are formed, and is preferably mounted to the base of the mechanism  40 . This configuration allows all of the multiple pins  60   a  (see  FIG. 5 ) mounted on the pin insertion assembly  60  to be partially inserted into a corresponding one of the apertures  30   a  at all times, and then, at the desired time, one of the pins is inserted further so that it extends through a respective aperture  23   a  of the rod and the remainder of the aperture  30   a , in order to thereby connect the rod  23  to the weights in the stack  30 . Multiple prime movers, which are preferably actuator solenoids  70 , are mounted to a frame  71  and are connected to the computer  90  using wiring, wireless connections or any other means. The computer can be a general purpose, programmable computer, programmed logic circuit (PLC) or any conventional device suitable for the purposes described herein. 
     Two shafts  74  and  76  are mounted to the frame  71 . Each of the solenoids  70  extends to a pivotal connection with a respective linkage  78 , which is preferably a flat metal plate with an aperture through which the shaft  74  extends to form a pivot. Upon actuation of one of the solenoids  70  as instructed by the computer  90  to withdraw its driveshaft from the position shown in  FIG. 7 , the linkage  78  is driven to pivot counterclockwise about the shaft  74 , forcing the respective pin  60   a  to be extended upwardly in the orientation of  FIG. 7 , which is in the direction of an associated aperture  30   a  in the weight stack  30  and an aligned aperture  23   a  in the rod  23 . The pin  60   a  so driven, extends through the aligned aperture  23   a  in the rod  23 , and then through the remainder of the aperture  30   a . In the inserted position, the respective pin  60   a  connects at least one weight in the stack  30  to the apparatus  20 , thereby enabling any weights above the respective pin to travel with the apparatus  20 . When the weight or weights are lifted, the pin insertion assembly  60  remains adjacent the portion of the weight stack  30  that is not lifted, but the pin that extends through the rod  23  is lifted with the rod. Each linkage  78  is limited in how far it can be displaced away from the weight stack  30  by the shaft  76  that fits into a groove at one side of the linkage  78 . 
     Each pin  60   a  has a shoulder  82  that seats against a reset bar  80   a  that is drivingly linked to the retraction solenoids  80 , which are also connected to the computer  90 . Upon actuation of the retraction solenoids  80  by instruction of the computer  90 , the reset bar  80   a  is pulled away from the weight stack (downwardly in the illustration of  FIG. 7 ), thereby withdrawing any pin  60   a  that is fully inserted into the entire aperture of the weight stack  30  and into the rod  23  by pulling the shoulders  82  of such pin  60   a  so that the pin  60   a  is only partially extending through the aperture  30   a  and not through the rod  23 . Once this withdrawal occurs, the mechanism  40  is reset and there is no pin in any rod aperture  23   a , which means there are no weights connected to the apparatus  20  and the cables  12   c  and  14   c.    
     The secondary weight stacks  32  and  34  operate in a similar manner to the weight stack  30 , except that there are not multiple weights to select among. Instead, the single weight in the secondary weight stacks  32  and  34  are either selected or it is not. The weight stack  34  preferably weighs 10 pounds, which, due to the mechanical advantage provided by the pulley arrangement, provides 5 pounds of resistance to a user pulling on the cable. The pin insertion assembly  160  is very similar to the pin insertion assembly  60  except that the assembly  160  has only one actuator solenoid  170  connected to the computer  90  for inserting a pin  170   a  completely into a single aperture through the weight stack  34  and an aperture in the rod  24  to connect the weight stack  34  to the rod  24 . A retraction solenoid  180  is also connected to the computer  90  and withdraws the pin  160   a  using a single linkage (not visible) substantially identical to the linkage  78 . 
     The weight stack  32  is preferably 20 pounds in weight, which, due to the mechanical advantage provided by the pulley arrangement, provides 10 pounds of resistance to a user pulling on the cable. The pin insertion assembly  260  is very similar to the pin insertion assembly  60  except that it has only one solenoid  270  connected to the computer  90  for inserting a pin (not visible) completely into a single aperture through the weight stack  32  and an aperture in the rod  22  to connect the weight stack  32  to the rod  22 . A retraction solenoid  280  is connected to the computer  90  and withdraws the pin using a single linkage (not visible) substantially identical to the linkage  78 . Thus, using the weight stacks  32  and  34 , five, ten or fifteen pounds can be added to each plate or set of plates in the weight stack  30 , each of which preferably weighs 40 pounds with effective resistance of 20 pounds after the mechanical advantage provided by the pulley connection. 
     It should be understood that the exact weight of each plate, and the number of combinations thereof, is not critical to the function of the weight selection apparatus  40 . Furthermore, there can be any desired and feasible number of weight stacks. The amount of weight that can be selected on the machine  10  preferably ranges from ten to 150 lbs by increments of five pounds, but this amount could be modified and still include the inventive features described herein. The amounts and combinations are described herein as examples, and a person having ordinary skill in the technology will understand from the explanation how to adapt the invention to any weight stack or weight amount. 
     The preferred means by which the weight selection mechanism  40  is actuated is shown in FIGS.  1  and  8 - 9 . The dial  100  is mounted on the face of the fitness machine  10 , preferably between about chest and eye levels. The dial  100  is shown in  FIG. 8  having a display  106  on its face, which is preferably an electronic display, such as a liquid crystal display (LCD), light-emitting diodes (LED), or equivalent visual image-forming apparatus that is human-perceivable. 
     The dial  100  is shown in  FIG. 9  connecting to a potentiometer  102  that is electrically or otherwise connected to the computer  90 . A gear  104  is an extension of the dial  100 , but could be linked through a drive mechanism. Upon rotation of the dial  100  in one direction or another about a central axis through its cylindrical body, the gear  104  rotates the potentiometer  102 , and the position of the gear  104  determines the signal the potentiometer  102  sends to the computer  90  to which all solenoids in the machine  10  are connected. Upon receipt of the signal from the potentiometer  102  indicating the position of the dial  100 , the computer  90  calculates the combination of available weights that equals the amount associated with the position of the dial, and the display  106  displays the amount of weight associated with the position of the dial. 
     An example of this is shown in  FIG. 8  at position (a) as the dial  100  is rotated clockwise from 10 lbs through 75 lbs at position (b) and further to 150 lbs at position (c). The rotation is stopped at position (d) and the computer  90  detects the halting of rotation as the signal to determine, from the amount of weight that has been selected, which actuators should be extended to connect the combination of weights to the apparatus  20 . Once the computer has determined the combination of weights based on programming code that is suited to the particular machine  10  the system is used with, the computer  90  actuates the retraction solenoids  80 ,  180  and  280  on the weight stacks  30 ,  32  and  34 , thereby withdrawing any pins that connect a weight to the apparatus  20 . This occurs on all weight stacks whether any pins are inserted or not, just to be certain that any pins are withdrawn. Next, the solenoids  70 ,  170  and/or  270  that are associated with the appropriate pins for the weight combination determined are actuated by the computer  90  to insert the desired pins through the rods  22 ,  23  and/or  24 , thereby connecting the selected amount of weight to the apparatus  20 . 
     Once the selected weight is connected to the apparatus  20 , which typically will take on the order of a few seconds from stopping the rotation of the dial  100 , the display of the dial  100  preferably indicates that the machine  10  is ready, such as by changing the color of the displayed text to green or some other color. During rotation of the dial  100 , the display can be blank, or the color of the numbers can be displayed in a different color, such as red or black. The type of indication can vary from a color change, but in any case it is preferred that the display  106  indicate in a human-perceptible manner (visible, audible, etc.) that the machine  10  is ready for use because the desired amount of weight has been connected to the machine&#39;s handles. 
     It should be noted that the method of clearing and then selecting weight can be varied from that described above. For example, the pins inserted can be removed when the machine  10  is idle for a predetermined period of time and the dial  100  and display  106  are reset. For safety purposes, it is desirable that no solenoids be actuated while the machine  10  is in use. Therefore, sensors are used to detect the position of the apparatus  20  relative to the weight stack  30 , and if the apparatus  20  is in a “home” position resting upon the weight stack, the computer  90  can actuate solenoids to insert or withdraw pins. If not, the computer  90  waits until the home position is achieved before actuating solenoids. 
     This detailed description in connection with the drawings is intended principally as a description of the presently preferred embodiments of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention and that various modifications may be adopted without departing from the invention or scope of the following claims.