Abstract:
A selectorized dumbbell has a handle that can be inserted into a gap between stacks of nested left and right weight plates that are provided in a plurality of nested weights. A selector determines how many left weight plates are coupled to the left end of the handle and how many right weight plates are coupled to the right end of the handle. A single left weight plate and a single right weight plate are interconnected together by an interconnection member of some type to form a single weight. The interconnection members of the different weights overlie one another and are provided with two arrays of a plurality of unique sets of holes and slots. A first connecting pin is inserted through the handle and through a selected set of holes and slots in the first array. A second connecting pin is inserted through the handle and through a selected set of holes and slots in the second array. The two pins together symmetrically couple the desired number of weights to the handle in a balanced fashion.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to a selectorized dumbbell having a selector that the user manipulates to adjust the mass of the dumbbell by coupling desired numbers of weight plates to opposite ends of a handle. 
       BACKGROUND OF THE INVENTION 
       [0002]    A full set of traditional dumbbells has various pairs of dumbbells with different mass, e.g. a pair of 5 pound dumbbells, a pair of 10 pound dumbbells, and so on. Such dumbbells are used for weight training exercises such as biceps curls, triceps extensions, etc. Different users will use whatever size dumbbells are most suited to their particular physical condition and exercise needs. For example, one user might lift 10 pound dumbbells while another user might lift 50 pound dumbbells. 
         [0003]    Such a dumbbell set is both costly to purchase and requires a fair amount of storage space. Storage racks are needed simply to store the various pairs of dumbbells. As a practical matter, individuals and small gyms or exercise clubs may not be able to afford either the money or the storage space required for a full set of traditional dumbbells. 
         [0004]    Selectorized dumbbells overcome the cost and space obstacles presented by traditional dumbbells. In a selectorized dumbbell, a plurality of weights are nested together. The weights provide a stack of nested left weight plates and a stack of nested right weight plates. The left and right stacks of weight plates are separated from one another by a gap. 
         [0005]    In a selectorized dumbbell, a handle is inserted into the gap between the left and right stacks of weight plates. A selector is then manipulated to determine how many of the left and right weight plates of the weights are coupled to the left and right ends of the handle. Once the selector is positioned to pick up a selected number of weights, the handle can then be lifted by the user from between the stacks of weight plates. The selected number of weights will rise with the handle to be used in performing various exercises with the dumbbell. 
         [0006]    The obvious advantages of selectorized dumbbells are the cost and space savings provided to the purchaser. Only two dumbbells need be purchased and not an entire set. Yet, these two dumbbells can provide a wide range of exercise mass depending upon how many of the nested weights are coupled to the handle by the selector. Moreover, the only storage space required is that needed for two dumbbells and the nested weights that accompany them. All of this can be stored on a small rack that takes up only a few square feet of floor space. Thus, a single pair of selectorized dumbbells provides an economical alternative to a full set of traditional dumbbells. 
         [0007]    The Applicants&#39; own U.S. Pat. No. 5,769,762 discloses a selectorized dumbbell in which the left and right weight plates in each stack thereof are coupled together in pairs by shallow, upwardly facing channels. Each weight thus comprises one left weight plate, one right weight plate and the interconnecting channel. The channel has vertically extending front and back walls. The channels of the different weights nest inside of another when the left and right weight plates are disposed in their nested stacks. When so nested, the front walls of the channels of all the weights overlie one another along a front side of the dumbbell and the back walls of the channels of all the weights similarly overlie one another along a back side of the dumbbell. 
         [0008]    The overlying front walls of the channels are provided with various sets of aligned holes and slots. The different sets of aligned holes and slots are unique so that different numbers of weights will be coupled to the handle and picked up when a connecting pin is inserted through one set of holes and slots. This is how one adjusts the weight of the dumbbell. The pin is inserted into that set of holes and slots that will pick up the desired number of weights. 
         [0009]    Identical sets of holes and slots are also arranged along the overlying back walls of the channels. The pin is long enough to extend between and span the distance between the front walls and the back walls of the channels. Thus, when the pin is inserted into a particular set of holes and slots in the front walls of the channels, the pin is long enough to extend through a corresponding set of holes and slots in the back walls of the channels. 
         [0010]    The sets of holes and slots are necessarily distributed along the lengths of the front and back walls of the channels. One set of holes and slots may be arranged along a transverse centerline of the dumbbell, i.e. a line passing through the center of the dumbbell perpendicular to the front and back walls of the channels. But, the other sets of holes and slots will inherently be set to one side or the other of this transverse centerline, i.e. will be off center relative to the transverse centerline. 
         [0011]    When the pin is inserted into any set of holes that is off center relative to the transverse centerline, the weights are coupled to the handle in an unbalanced configuration. The weight plates that are furthest from the pin will exert a torque about the pin that is greater than the torque exerted by the weight plates that are closest to the pin. This will cause the weight plates that are furthest from the pin to slightly droop or sag relative to the handle. 
         [0012]    This is disadvantageous as it leaves the user with the impression that the weights are not securely attached to the handle even when they are. In addition, the dumbbell can feel somewhat unbalanced to the user when the user picks it up and exercises with it. This is particularly true when the pin is inserted through one of the outermost sets of holes and slots in which the pin is the furthest away from one set of the weight plates. In this pin orientation, the sense of unbalance is at its most pronounced. 
         [0013]    In addition, the weights are coupled to the handle using only a single connecting pin with a single connecting prong. While the prong of the pin extends all the way through the dumbbell between the front and back walls of all the channels, there is always a possibility that the pin could become accidentally dislodged during use. In this case, the weights would detach from the handle. 
         [0014]    Accordingly, there is a need in the art for a selectorized dumbbell in which the weights would be attached to the handle by a selector that couples the weights to the handle in a balanced manner from side to side. Desirably, such a selector would have a redundant safety mechanism for helping keep the weights securely attached to the handle even if a portion of the selector were inadvertently dislodged. 
       SUMMARY OF THE INVENTION 
       [0015]    One aspect of this invention relates to an adjustable dumbbell which comprises a lifting handle having a hand grip. The handle has a transverse centerline substantially perpendicular to the hand grip. A plurality of individual weights have overlying portions. A plurality of sets of aligned holes and slots are placed in the overlying portions of the weights. Each set has a unique arrangement of holes and slots. Two duplicate arrays of the plurality of sets of aligned holes and slots are provided with one array being placed to the left of the transverse centerline and the other array being substantially symmetrically placed to the right of the transverse centerline. A connecting pin is selectively insertable through any one set of holes and slots in a particular array of holes and slots to select for use a particular weight or weights as determined by the hole and slot arrangement in the set through which the pin passes. Two individual connecting pins are provided with one pin passing through a selected set of holes and slots in one array and the other pin passing through a corresponding set of holes and slots in the other array, whereby the pair of pins connect the weights to the handle symmetrically relative to the transverse centerline. 
         [0016]    Another aspect of this invention relates to a selectorized dumbbell which comprises a stack of nested left weight plates separated by a gap from a stack of nested right weight plates. A handle can be inserted into the gap between the weight plate stacks. The handle has a hand grip. A selector determines how many left weight plates are coupled to a left end of the handle and how many right weight plates are coupled to a right end of the handle. The selector comprises a pair of individual connecting pins that are separate from one another with the connecting pins being individually insertable into and through different portions of the handle in an insertion direction that is perpendicular to the hand grip to couple different numbers of left and right weight plates to the left and right ends of the handle. 
         [0017]    Yet another aspect of this invention relates to a selectorized dumbbell which comprises a handle that can be inserted into a gap between stacks of nested left and right weight plates that are provided in a plurality of nested weights. A selector determines how many left weight plates are coupled to the left end of the handle and how many right weight plates are coupled to the right end of the handle. A single left weight plate and a single right weight plate are interconnected together by an interconnection member to form a single weight. The interconnection members of the different weights overlie one another and are provided with two duplicate arrays each having a plurality of unique sets of holes and slots. The selector comprises a first connecting pin inserted through the handle and through a selected set of holes and slots in one array thereof, and a second connecting pin that is separate and distinct from the first connecting pin with the second connecting pin being inserted through the handle and through a selected set of holes and slots in the other array thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    This invention will be described more completely in the following Detailed Description, when taken in conjunction with the following drawings, in which like reference numerals refer to like elements throughout. 
           [0019]      FIG. 1  is a front plan view of one embodiment of a selectorized dumbbell according to this invention with the selector and holes and slots having been omitted from this view in favor of their illustration in  FIGS. 4-7 ; 
           [0020]      FIG. 2  is a side elevational view of the selectorized dumbbell of  FIG. 1 ; 
           [0021]      FIG. 3  is a perspective view of one end of one weight of the selectorized dumbbell of  FIG. 1 , particularly illustrating one of the weight plates of the weight along with the carrier that holds the weight plate to a pair of rails; 
           [0022]      FIG. 4  is a perspective view of a portion of the selectorized dumbbell of  FIG. 1 , particularly illustrating the twin pin selector for coupling a desired number of weights to the handle; 
           [0023]      FIG. 5  is a perspective view similar to  FIG. 4 , but having a portion of the handle removed to better illustrate the twin pin selector and its interaction with the sets of holes and slots in the front and back rails; 
           [0024]      FIG. 6  is a perspective view similar to  FIGS. 4 and 5 , but having one of the twin pins removed to better illustrate the sets of holes and slots in the front and back rails; 
           [0025]      FIG. 7  is a perspective view similar to  FIGS. 4-6 , but having the back rails and one of the pins shown in an exploded form; 
           [0026]      FIG. 8  is a perspective view of a dumbbell according to this invention, particularly illustrating an alternative embodiment for the pins comprising the selector; 
           [0027]      FIG. 9  is a perspective view of a dumbbell according to this invention, particularly illustrating a guide block that may be used in the dumbbell to help a user insert the connecting pins; and 
           [0028]      FIG. 10  is a perspective similar to  FIG. 9 , particularly illustrating the top of the guide block in an exploded form to illustrate the interior of the guide block. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    One embodiment of a selectorized dumbbell according to this invention is illustrated generally as  2  in  FIG. 1 . Dumbbell  2  is similar to that shown in the Applicants&#39; U.S. Pat. Nos. 5,769,762 and 7,153,244, which are hereby incorporated by reference. Only those features of dumbbell  2  which relate to this invention will be described in detail herein. The materials incorporated by reference above can supply other information regarding the general structure and operation of dumbbell  2  in the event the reader hereof desires or requires such information. 
         [0030]    Dumbbell  2  is illustrated in  FIG. 1  having three nested weights  4 . Weights  4  provide a stack of nested left weight plates  6   l  and a stack of nested right weight plates  6   r . The number of nested weights  4  can obviously vary. For example, dumbbell  2  shown in  FIGS. 4-7  is configured to provide five nested weights rather than three. If desired, dumbbell handle  8  can also permanently carry a weight plate  7  at each end thereof as shown in  FIG. 1 . Alternatively, as shown in  FIGS. 4-7 , each end of handle  8  could simply comprise a side flange  9  that is free of any handle carried weight plates. 
         [0031]    Handle  8  is inserted into a gap between the two stacks of nested left and right weight plates  6   l  and  6   r . The position of a selector  10  determines how many nested weights  4  are coupled to handle  8 . This is how a user varies the exercise mass of a selectorized dumbbell  2 , namely by adjusting selector  10 . After a desired numbers of weights  4  are coupled to handle  8 , the user can grip a hand grip  11  on handle  8  and lift upwardly on handle  8  to pick up the desired number of weights. 
         [0032]    Each weight plate  6  in the various weights  4  is held between the arms  12  of a forked carrier  14 . As shown in  FIGS. 1 and 3 , arms  12  extend upwardly from an underlying base  16  of carrier  14 . Base  16  of carrier  14  is substantially rigid. Arms  12  taper inwardly as they rise from base  16  of carrier  14  to be generally triangular in shape. Arms  12  can be flexible if desired and are substantially smaller than weight plate  6  carried between arms  12 . 
         [0033]    Carriers  14  are made in two halves  14   a  and  14   b  as indicated in  FIGS. 1 and 3  by the parting line  15  between halves  14   a ,  14   b . Each carrier half  14   a  and  14   b  carries one of the flexible arms  12  in each pair of arms  12 . Carrier halves  14   a ,  14   b  are secured together by a plurality of attachment bolts  18  and nuts  20  shown in  FIG. 3 . When secured together, bolts  18  and nuts  20  are recessed within the left and right sides of base  16  of carrier  14  so that they do not project laterally outwardly beyond the left and right sides of base  16  of carrier  14 . Carrier halves  14   a ,  14   b  are also formed so as to provide a slot  22  in each of the front and back sides of base  16  of carrier  14  along parting line  15  between carrier halves  14   a ,  14   b . Each carrier  14  extends perpendicularly relative to the axis of handle  8 . 
         [0034]    The upper ends of arms  12  of carrier  14  each have an inwardly protruding cylindrical stub shaft  24  for mounting weight plate  6  between arms  12 . Stub shafts  24  on the pair of arms  12  protrude partly into a central mounting hole  5  provided in each weight plate  6  from either side of hole  5 . Another attachment bolt  26  and nut  28  are provided to secure the upper ends of arms  12  together. When this occurs, stub shafts  24  abut one another to form, in effect, a cylindrical hub. This also holds weight plate  6  between arms  12  with hole  5  of weight plate  6  being concentrically received on the hub formed by stub shafts  24  on arms  12  of carrier  14 . Again, the head of attachment bolt  26  and nut  28  are seated in recesses in arms  12  so that the attachment bolt and nut do not protrude beyond the outer faces of arms  12 . 
         [0035]    Each nested weight  4  preferably comprises a pair of carriers  14  and a pair of weight plates  6 , namely a first carrier  14  carrying left weight plate  6   l  and a second carrier  14  carrying right weight plate  6   r . Weight plates  6  comprising each weight  4  are laterally spaced apart from one another. A pair of interconnecting members comprising a front rail  30   f  and a back rail  30   b  unite or join the laterally spaced apart weight plates  6  together. The front and back rails  30  used in different weights  4  have progressively increasing lengths as one proceeds from the inner to the outer weights  4  in each stack. This progressively increases the spacing between the left and right weight plates  6   l  and  6   r  in each weight  4  to allow the different weights  4  to be nested together. Rails  30  comprise strap like steel rails having a substantially flat cross-sectional profile. 
         [0036]    Opposite ends of rails  30  are easily bent into an L-shape to provide inturned ends  34 . Ends  34  are received in slots  22  formed along the parting lines  15  between carrier halves  14   a ,  14   b . Each inturned end  34  includes an opening  36  for allowing one of the attachment bolts  28  that secure carrier halves  14   a ,  14   b  together to pass through the end  34  of rail  30 . Like the lengths of rails  30 , inturned ends  34  of rails  30  progressively increase in depth from rails  30  used on the inner to the outer weights  6  in each stack. This allows rails  30  of the different weights  4  to nest inside one another as shown in  FIGS. 4-8 . 
         [0037]    Referring now to  FIGS. 4-8 , rails  30  are provided with duplicate left and right arrays  40   l  and  40   r  of various sets a-e of holes  42  and slots  44 . A transverse centerline of dumbbell  2  is indicated as c l  in  FIG. 5 . The left hole and slot array  40   l  is so named and labelled as it is spread out along the length of rails  30  to the left of transverse centerline c l . Similarly, as can be seen in  FIG. 5 , the right hole and slot array  40   r  is spread out along the length of rails  30  to the right of transverse centerline c l . Transverse centerline c l  is itself perpendicular to the hand grip  11  of handle  8  and to the direction of elongation of rails  30 . 
         [0038]    Each hole and slot array  40 , whether it be the left array  40   l  or the right array  40   r , is identical and comprises various unique sets a-e of holes  42  and slots  44 . Each set a-e of holes  42  and slots  44  extends parallel to transverse centerline c l . The number of sets a-e of holes  42  and slots  44  in each array  40  corresponds to the number of weights  4 . Since dumbbell  2  of  FIGS. 4-8  is shown configured to support five weights  4 , each array  40  has five sets of holes  42  and slots  44 , namely set a, set b, set c, set d and set e. 
         [0039]    Looking at the different sets a-e of holes  42  and slots  44  in each array  40 , set a is the innermost set of holes  42  and slots  44 , set b is located immediately outside of set a, set c is located immediately outside of set b, and so on to the last set, set e, which is the outermost set of holes  42  and slots  44  in the array  40 . The sets a-e of holes  42  and slots  44  are unique in the following manner: 
         [0000]    set a has one hole  42   a  and four slots  44   a  transversely aligned therewith;
 
set b has two holes  42   b  and three slots  44   b  transversely aligned therewith;
 
set c has three holes  42   c  and two slots  44   c  transversely aligned therewith;
 
set d has four holes  42   d  and one slot  44   d  transversely aligned therewith; and
 
set e has five transversely aligned holes  42   e  and no slots.
 
         [0040]      FIG. 7  shows how rails  30  are bored and slotted to provide the different sets of aligned holes  42  and slots  44 . The slotted portions of rails  30  have different lengths rather than being individual slots  44  so that the longer slotted portions in rails  30  effectively provide multiple slots  44  in the different sets a-d. In this case, adjoining sections of the long slotted portions of rail  30  provide different slots  44  in the different sets a-d. For example, looking at  FIG. 6 , note how the very long slotted portion in the first or outermost rail  30   f  or  30   b  effectively overlies all of the holes  42  in the remaining four inner rails  30   f  or  30   b . Thus, the long slotted portion in the first or outermost rail  30   f  or  30   b  effectively forms four slots  44   a ,  44   b ,  44   c , and  44   d  for the four sets a-d, respectively. See  FIG. 7 . As noted earlier, the outermost rail  30  could have had four individual slots  44   a ,  44   b ,  44   c  and  44   d  cut into it to do the same thing, but simply using adjacent portions of one long slot  44  is also effective. 
         [0041]    Selector  10  comprises a pair of individual connecting pins  50 . A left connecting pin  50 l is provided for the left array  40   l  of holes  42  and slots  44 . A right connecting pin  50   r  is provided for the right array  40   r  of holes  42  and slots  44 . Left and right connecting pins  50 l and  50   r  are identical to one another. 
         [0042]    As shown in  FIG. 4 , handle  8  has a U-shaped base  70  with downwardly extending front and back walls  72   f  and  72   b . Each wall  72  has a series of spaced holes  74  that correspond to the number of sets a-e of holes  42  and slots  44  in the two arrays  40   l  and  40   r . Since each array  40  has five sets a-e, each wall  72  will have ten holes  74 . Each hole  74  in each wall  72  aligns with one set a, b, c, d, or e of holes  42  and slots  44  in one of the arrays  40   l  or  40   r . 
         [0043]    Each connecting pin  50  has an elongated connecting prong  52  that is long enough to extend transversely through dumbbell  2  and span between and through front rails  30   f  and back rails  30   b  and between and through front and back walls  72   f  and  72   b  of handle base  70 . Connecting prong  52  is rigidly connected to a base  54  that is itself rigidly connected to an enlarged outer knob or head  56 . Base  54  carries a plurality of recesses  58  in which magnets  60  are received. Thus, when connecting pin  50  is inserted into one of the sets a-e of holes  42  and slots  44  in rails  30  and into the corresponding hole  74  on handle base  70 , as shown in  FIGS. 4-8 , base  54  of connecting pin  50  is magnetically attracted to the front wall  72   f  of handle base  70  to help hold pin  50  in place. See  FIG. 4 . 
         [0044]      FIG. 8  discloses an alternative form of connecting pin  50 . In this pin  50 , the enlarged head  56  includes a resilient detent finger  57  having a downwardly extending hook or tab  59  on the front end thereof. Base  70  of handle  8  has a series of upwardly facing detent holes  76  that correspond in number and placement to the connecting holes  74  in the front and back walls  72   f  and  72   b  of base  70 . When pin  50  as shown in  FIG. 8  is pushed into one of the sets a-e of holes  42  and slots  44  in each array  40   l  and  40   r  thereof, tab  59  of detent finger  57  will snap down into one of the detent holes  76  in base  70  of handle  8  to help hold pin  50  in place. Thus, this form of pin  50  uses a mechanical detent rather than a magnetic attraction to help retain pin  50  in place. 
         [0045]    It should be apparent that the weight of dumbbell  2  is adjusted by selecting which set of holes  42  and slots  44  is used to receive pin  50 . If pin  50  is inserted into set a, then only one weight  4  will be coupled to handle  8 , namely the innermost nested weight  4 . That is so because pin  50  only passes through one hole  42   a , namely the hole  42   a  in the rails  30   f  and  30   b  for weight  4 , and otherwise passes through the slots  44   a  in the rails  30  for all the other weights. In this position, when handle  8  is lifted, only the innermost nested weight  4  comes with it. 
         [0046]    If the user wants to increase the amount of weight coupled to handle  8 , the user need only adjust pin  50  to be inserted through one of the other sets b-e of holes  42  and slots  44 . If set b is used, two weights  4  get picked up. If set c is used, three weights  4  get picked up, and so on until all five weights get picked up when set e is used. Thus, the exercise mass provided by dumbbell  2  can be easily adjusted simply by inserting connecting pin  50  into one of the sets a-e of holes  42  and slots  44 . 
         [0047]    Dumbbell  2  has duplicate left and right arrays  40   l  and  40   r  of sets a-e on holes  42  and slots  44  arranged in both front rails  30   f  and back rails  30   b . Selector  10  comprises two left and right connecting pins  50   l  and  50   r , one for each array  40   l  and  40   r . Thus, the weights  4  get pinned to handle  8  at symmetrical locations relative to the centerline c l  so that the pinning is not unbalanced to one side or the other of centerline c l . This is an advantage since it provides a more secure engagement and prevents dumbbell  2  from ever feeling unbalanced to the user. 
         [0048]    In addition, as the weight carried by handle  8  increases, pins  50  get progressively further spread out along rails  30  to increase the distance between pins  50 . This also helps provide a stable and secure feeling of engagement as the amount of weight carried by handle  8  increases. However, the inverse could be alternatively used if desired, i.e. pins  50  could get closer together as the number of weights  4  coupled to handle  8  increases. 
         [0049]    Another advantage of the twin pins  50  disclosed herein is an added layer of safety. Even if one pin  50  is accidentally dislodged, the other remaining pin  50  will be strong enough to keep weights  4  coupled to handle  8 . 
         [0050]    Referring now to  FIGS. 9 and 10 , a guide block  80  could be attached to the underside of base  70  of handle  8  by a plurality of bolts  82 . Guide block  80  has a plurality of transverse channels  84  extending therethrough between the front and back sides of guide block  80 . Each channel  84  is aligned with one of the sets a-e of holes  42  and slots  44  in each array  40  thereof. Channels  84  help the user properly insert connecting pins  50  into a desired set a, b, c, d or e of holes  42  and slots  44  with channels  84  helping guide connecting prongs  52  across the distance between front rails  30   f  and back rails  30   b . Thus, the user need not hunt and peck for the correct set of holes on the back rails  30   b  but will be guided thereto by guide channels  84  in guide block  80 . However, guide block  80  could be dispensed with if so desired. 
         [0051]    Various other modifications of this invention will be apparent to those skilled in the art. Thus, the scope of this invention is to be limited only by the appended claims.