U.S. patent application number 11/957685 was filed with the patent office on 2008-07-03 for magnetically guided exercise devices and systems.
This patent application is currently assigned to LUMPEE PROPERTIES, LTD.. Invention is credited to Parker S. Lumpee.
Application Number | 20080161170 11/957685 |
Document ID | / |
Family ID | 39584831 |
Filed Date | 2008-07-03 |
United States Patent
Application |
20080161170 |
Kind Code |
A1 |
Lumpee; Parker S. |
July 3, 2008 |
MAGNETICALLY GUIDED EXERCISE DEVICES AND SYSTEMS
Abstract
A strength training apparatus comprises a frame. In addition,
the strength training apparatus comprises an elongate guide member
including a magnet. Further, the strength training apparatus
comprises a weight plate including a guide bore through which the
guide member is disposed that includes a magnet corresponding to
the magnet of the guide member. The magnet of the guide bore and
the magnet of the guide member are oriented to produce repulsive
magnetic forces between the weight plate and the guide member.
Inventors: |
Lumpee; Parker S.; (College
Station, TX) |
Correspondence
Address: |
CONLEY ROSE, P.C.;David A. Rose
P. O. BOX 3267
HOUSTON
TX
77253-3267
US
|
Assignee: |
LUMPEE PROPERTIES, LTD.
College Station
TX
|
Family ID: |
39584831 |
Appl. No.: |
11/957685 |
Filed: |
December 17, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60870983 |
Dec 20, 2006 |
|
|
|
Current U.S.
Class: |
482/98 |
Current CPC
Class: |
A63B 2209/08 20130101;
A63B 21/0628 20151001; A63B 2225/30 20130101 |
Class at
Publication: |
482/98 |
International
Class: |
A63B 21/062 20060101
A63B021/062 |
Claims
1. A strength training apparatus including: a frame; an elongate
guide member including a magnet; a weight plate including a guide
bore through which the guide member is disposed that includes a
magnet corresponding to the magnet of the guide member; where the
magnet of the guide bore and the magnet of the guide member are
oriented to produce repulsive magnetic forces between the weight
plate and the guide member.
2. The strength training apparatus of claim 1 wherein the magnet of
the weight plate and the magnet of the guide bore maintain a gap
between the inner surface of the guide bore and the outer surface
of the guide member as the weight plate moves along the guide
member.
3. The strength training apparatus of claim 2 wherein the magnet of
the guide member includes a magnetic insert disposed within a
recess provided in the outer surface of the guide member.
4. The strength training apparatus of claim 3 wherein the magnet of
the guide bore includes a magnetic insert disposed within a recess
provided in the outer surface of the guide member.
5. The strength training apparatus of claim 2 wherein: the guide
member includes a plurality of magnetic inserts, each magnetic
insert disposed in a recess provided in the outer surface of the
guide member; the weight plate includes a plurality of magnetic
inserts, each magnetic insert disposed in a recess provided in the
inner surface of the guide bore; each magnetic insert of the guide
member is positioned opposite one of the magnetic inserts of the
guide bore; and the magnetic inserts in the guide member are
oriented to repel the magnetic inserts in the guide bore.
6. The strength training apparatus of claim 2 wherein the entire
outer surface of the guide member includes a magnet.
7. The strength training apparatus of claim 6 wherein the entire
inner surface of the guide bore includes a magnet.
8. The strength training apparatus of claim 6 wherein the guide
member is made from a magnetic material.
9. The strength training apparatus of claim 8 wherein the weight
plate is made from a magnetic material.
10. The strength training apparatus of claim 2 further including a
plurality of guide members and a plurality of guide bores through
the weight plate, each guide member disposed in one of the guide
bores.
11. A strength training apparatus including: a weight plate
including a magnet; an elongate guide member disposed adjacent and
spaced apart from the weight plate and including a weight plate
facing surface including a magnet corresponding to the magnet of
the weight plate; where the magnet of the guide member and the
magnet of the weight plate are oriented to produce repulsive
magnetic forces between the weight plate and the guide member to
maintain the gap therebetween.
12. The strength training apparatus of claim 11 wherein the magnet
of the guide member includes a magnetic insert disposed within a
recess provided in the weight plate facing surface of the guide
member.
13. The strength training apparatus of claim 12 wherein the magnet
of the weight plate includes a magnetic insert disposed within a
recess provided in the outer surface of the weight plate.
14. The strength training apparatus of claim 13 wherein: the guide
member includes a plurality of magnetic inserts, each magnetic
insert disposed in a recess provided in the weight plate facing
surface of the guide member; the weight plate includes a plurality
of magnetic inserts, each magnetic insert disposed in a recess
provided in the outer surface of the weight plate; each magnetic
insert of the guide member is positioned opposite one of the
magnetic inserts of the weight plate; and the magnetic inserts in
the guide member are oriented to repel the magnetic inserts in the
guide bore.
15. The strength training apparatus of claim 14 including a
plurality of guide members and wherein the weight plate is
rectangular and one of the guide members is positioned at each
corner of the weight plate.
16. The strength training apparatus of claim 15 wherein each guide
member has an L-shaped cross section disposed about one of the
corners of the weight plate.
17. The strength training apparatus of claim 6 wherein the guide
member is made from a magnetic material.
18. A method for guiding the movement of a weight plate of a weight
training machine including: positioning an elongate guide member
adjacent the weight plate; creating a gap between the guide member
and the weight plate; and generating a repulsive magnetic force
between the guide member and the weight plate.
19. The method of claim 18 further including moving the weight
plate relative to the guide member and substantially maintaining
the gap between the guide member and the weight plate by using the
repulsive magnetic force.
20. The method of claim 19 further including positioning the guide
member through a guide bore provided in the weight plate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. provisional
application Ser. No. 60/870,983 filed Dec. 20, 2006, and entitled
"Magnetically Guided Exercise Devices and Systems," which is hereby
incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND
[0003] Proper exercise and weight training have long been
recognized as beneficial for improving cardiovascular health as
well as strength. Most individuals weight train in local gyms or
exercise clubs that provide access to a variety of conventional
weight lifting machines, such as Nautilus.RTM. and Cybex.RTM. type
machines. Most of these conventional weight lifting machines
comprise a relatively rigid frame, a pulley system, and a vertical
stack of weight plates. The frame typically includes two parallel
vertical guide rods that each pass through a vertical bore formed
in the stack of weights. The guide rods generally maintain the
vertical orientation of the stack of weight plates and guide the
vertical motion of one or more of the individual weight plates
during use of the machine. In most cases, a vertically oriented
weight selection bar coupled to the pulley system also passes
vertically through the central portion of the stack of weights and
is manually coupled to one or more of the weight plates, typically
by a pin. The user of the machine can select the desired amount of
total weight to be lifted by manually changing the location of the
pin, thereby increasing or decreasing the number of weight plates,
and hence, the total amount of weight, coupled to the weight
selection bar. With the desired amount of weight coupled to the
weight selection bar, the user exerts a force through the pulley
system to either raise the one or more weight plates coupled to the
weight selection bar against gravity. As the weights are lifted by
the user they move vertically relative to the guide rods, their
vertical motion controlled and guided the guide rods.
[0004] Most conventional weight lifting machines also include
mechanical bushings positioned between the stack of weight plates
and one or both guide rods. The mechanical bushings, which may be
roller-type bushings, are intended to reduce frictional forces
between the moving weight plates and the guide rods and enable
smooth operation of the weight machine. However, since these
mechanical bushings physically contact one or more guide rods, some
frictional forces inevitably arise the interface between the
bushings and the guide rods, even if the guide rods are polished
smooth. Such friction and wear the bushings and guide rods over
time. Further, as the guide rods and bushings get dirty, the
friction between the bushings and guide rods tends to increase due
to an increase in the coefficient of friction therebetween.
[0005] Inadequate and/or dirty bushings may cause abrupt and
unpredictable movement of the weights being lifted, which may
result in injury to the user. For instance, if a bushing sticks,
the user may begin to exert a greater force on the pulley system
until the bushing suddenly "breaks free", resulting in an abrupt
movement or jerk of the weights. In addition, a failure of one of
these bushings may result in an undesired effective increase in the
total amount of weight being lifted by the user. For example,
frictional forces between a bad bushing and a guide rod will act
against the relative motion therebetween, thereby increasing the
overall resistance the user must overcome to lift the weight.
[0006] To ensure the mechanical bushings between the weight plates
and guide rods are working properly, regular inspection and
maintenance is often required. For instance, periodically, the
bushings must be visually inspected and repaired if necessary. In
addition, the bushings and guide rods may need periodic cleaning to
ensure a smooth sliding contact between the bushings and guide
rods, and to reduce the buildup of dirt or other contaminants which
could reduce the effectiveness of the bushings over time. In some
gyms and health clubs that have twenty, thirty, fifty or more
weight machines, the daily maintenance and cleaning of bushings and
guide rods can take up a significant amount of time and effort.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] For a detailed description of the embodiments of the
invention, reference will now be made to the accompanying drawings
in which:
[0008] FIG. 1 is a front view of an embodiment of a strength
training machine constructed in accordance with the principles
described herein;
[0009] FIG. 2 is a side view of the strength training machine of
FIG. 1;
[0010] FIG. 3 is a partial enlarged front view of the stack of
weight plates and guide members of the strength training machine of
FIG. 1;
[0011] FIG. 4 is a cross-sectional view taken along line 2-2 of
FIG. 3;
[0012] FIG. 5 is a partial enlarged front view of an embodiment of
a strength training machine constructed in accordance with the
principles described herein; and
[0013] FIG. 6 is a cross-sectional view taken along line 3-3 of
FIG. 5.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] The following discussion is directed to various embodiments
of the invention. The embodiments disclosed should not be
interpreted, or otherwise used, as limiting the scope of the
disclosure, including the claims. In addition, one skilled in the
art will understand that the following description has broad
application, and the discussion of any embodiment is meant only to
be exemplary of that embodiment, and not intended to intimate that
the scope of the disclosure, including the claims, is limited to
that embodiment.
[0015] Certain terms are used throughout the following description
and claims to refer to particular features or components. As one
skilled in the art will appreciate, different persons may refer to
the same feature or component by different names. This document
does not intend to distinguish between components or features that
differ in name but not function. The drawing figures are not
necessarily to scale. Certain features and components herein may be
shown exaggerated in scale or in somewhat schematic form and some
details of conventional elements may not be shown in interest of
clarity and conciseness.
[0016] In the following discussion and in the claims, the terms
"including" and "comprising" are used in an open-ended fashion, and
thus should be interpreted to mean "including, but not limited to .
. . ." Also, the term "couple" or "couples" is intended to mean
either an indirect or direct connection. Thus, if a first device
couples to a second device, that connection may be through a direct
connection, or through an indirect connection via other devices and
connections.
[0017] Referring to FIGS. 1-3, a strength or weight training
machine 10 is illustrated. Machine 10 includes a rigid frame 20
that supports a pulley system 30, a mounting apparatus 45, and a
plurality of weight plates 51 forming a weight stack 50. Pulley
system 30 includes pulleys 32 rotationally coupled to frame 20 and
a cable 35 that passes over and is guided by pulleys 32. Cable 35
has a first end 35a coupled to a user interface member 40 and a
second end 35b coupled to a weight selection bar 70. In general,
user interface member 40 is the structure manipulated by the user
of machine 10 for strength training. In this embodiment, user
interface member 40 is a rigid bar that is pulled by the user of
machine 10, however, in general, the user interface member (e.g.,
user interface member 40) may comprise any suitable device that is
manipulated (e.g., pushed, pulled, rotated, etc.) by an individual
using the weight training machine (e.g., machine 10).
[0018] Weight selection bar 70 is an elongate member slidingly
received in a generally mating selection bar bore 71 that passes
generally through the center of weight stack 50. Weight selection
bar 70 is coupled, usually by a pin, to one or more individual
weight plates 51. By adjusting the number of individual weight
plates 51 coupled to weight selection bar 70, the user can select
the desired amount of total weight to be lifted. In addition, two
guide member bores 61 are provided through weight stack 50 to
slidingly receive guide bars or members 60. The ends of each guide
member are fixed to frame 20.
[0019] Guide members 60 substantially maintain the orientation of
weight stack 50 and serve to guide the motion of one or more
individual weight plates 51 coupled to weight selection bar 70. In
particular, during use, an individual will generally select a
desired weight resistance by coupling a desired number of weight
plates 51 to weight selection bar 70. This is usually accomplished
manually with a pin. With the user properly positioned in mounting
structure 45, the used grasps user interface member 40 and pulls
(or pushes depending on the weight machine) on interface member 40.
Interface member 40 is coupled to the desired amount of weight
coupled to weight selection bar 70 via cable 35. Thus, the force
applied by the user to interface member 40 is translated through
cable 35 and weight selection bar 70 to the individual weight
plates 51 coupled to weight selection bar 70. If this force is
sufficient, cable 35, weight selection bar 70, and the individual
weight plates 51 coupled to weight selection bar 70 will be lifted.
As the individual weight plates 51 move relative to frame 20, guide
members 60 maintain the orientation of individual weight plates 51
and generally guide their motion.
[0020] Referring now to FIGS. 3 and 4, the user couples one or more
weight plates 51 to weight selection bar 70 to achieve the desired
total amount of weight to be lifted. In this embodiment, the user
slides a pin (not shown) through an aperture 73 in a specific
weight plate 51, termed the "pinned" weight plate 51, and through a
mating pin bore 74 in weight selection bar 70 that is aligned with
aperture 73. Once the pin is sufficiently inserted through aperture
73 and mating pin bore 74, the pinned weight plate 51 and each
weight plate 51 disposed above the pinned weight plate 51 is
coupled to weight selection bar 70. During use of machine 10, each
weight plate 51 coupled to weight selection bar 70 moves relative
to frame 20 and guide members 60, with the motion generally guided
by guide members 60.
[0021] As best shown in FIG. 4, each weight plate 51 includes two
guide member bores 61a that each slidingly receives a guide member
60 and a selection bar bore 71a that slidingly receives weight
selection bar 70. In this embodiment, guide member bores 61a are
generally disposed proximal opposite ends of weight plate 51, and
select bar bore 71a is disposed at the center of weight plate 51.
However, it should be appreciated that the bores may also be
located in other positions within the weight plates 51. Individual
weight plates 51 are stacked and oriented such that bores 61a, 71a
provided in each individual weight plate 51 are aligned, thereby
defining bores 61, 71, respectively, through weight stack 50.
[0022] Referring specifically to FIG. 4, each individual weight
plate 51 also includes a plurality of plate magnetic inserts 80
disposed in mating recesses 81 provided in each weight plate 51. In
this embodiment, four recesses 81 are equally angularly spaced
about 90.degree. apart along the inner surface of each guide member
bore 61a. However, in general, one or more recess (e.g., recesses
81) and plate magnetic inserts (e.g., plate magnetic inserts 80)
may be provided along the inner surface of each guide member bore
(e.g., guide member bore 61a) at any suitable location(s). In some
embodiments, the plate magnetic inserts may not be disposed in
recesses. In still other embodiments, the entire inner surface of
the guide member bore may comprise a plate magnetic insert.
[0023] Referring still to FIG. 4, each guide member 60 includes a
plurality of guide magnetic inserts 90 disposed in mating recesses
91 provided in the outer surface of each guide member 60 throughout
the range of travel of the weight plates 51. In this embodiment,
four recesses 91 are equally spaced approximately 90.degree. apart
around the outer surface of each guide member 60. However, in
general, one or more recess (e.g., recesses 91) and guide magnetic
inserts (e.g., guide magnetic inserts 90) may be provided along the
outer surface of each guide member (e.g., guide member 60) at any
suitable location(s). In some embodiments, the guide magnetic
inserts may not be disposed in recesses. In still other
embodiments, the entire outer surface of the guide member may
comprise a plate magnetic insert.
[0024] Magnetic inserts 80, 90 may be secured to each weight plate
51 and guide member 60 by any suitable means including, without
limitation, an interference fit with recesses 81, 91, respectively,
adhesives, a welded connection, or combinations thereof. In
addition, recesses 81, 91 may be molded or cast, as part of each
weight plate 51 and each guide member 60, respectively, or machined
from each weight plate 51 and guide member 60, respectively. In
other embodiments, the magnetic inserts (e.g., magnetic inserts 80,
90) may be integral with each weight plate and/or each guide
member.
[0025] Referring still to FIG. 4, each guide magnetic insert 90 is
positioned substantially opposite and facing a corresponding plate
magnetic insert 80. Thus, for each guide magnetic insert 90 in the
outer surface of each guide member 60, there is a corresponding
plate magnetic insert 80 provided in the inner surface of each
guide member bore 61. However, magnetic inserts 80, 90 are radially
spaced apart by an annulus or gap 85 positioned between each weight
plate 51 and each guide member 60. Specifically, each guide member
bore 61a has a radius R.sub.1 defined by the inner surface of each
guide member bore 61a, and each guide member 60 has a radius
R.sub.2 defined by the outer surface of each guide member 60, where
radius R.sub.1 is greater than radius R.sub.2, resulting in gap
85.
[0026] Magnetic inserts 80, 90 are oriented such that the common
poles of magnetic inserts 80, 90 face each other across gap 85,
resulting in repulsive magnetic forces between magnetic inserts 80,
90. The repulsion between magnetic inserts 80, 90 and the
positioning of the magnetic inserts throughout the range of travel
of the weight plates 51 offers the potential to maintain gap 85 and
the physical separation of each weight plate 51 and each guide
member 60 as each weight plate 51 moves relative to guide members
60, while still allowing guide members 60 to guide the movement of
each weight plate 51. The potential to maintain the physical
separation of each guide member 60 and each weight plate 51, also
enables reduced contact and associated friction between weight
plates 51 and guide members 60, thereby offering the potential for
relatively consistent, smooth motion of weight plates 51 relative
to frame 20 and guide members 60. Such a configuration employing
magnetic inserts (e.g., magnetic inserts 80, 90) in the guide
members (e.g., in guide members 60) and in the individual weight
plates (e.g., in each weight plates 51) to maintain physical
separation of the guide members and the weight plates may be termed
herein as a "magnetic bushing."
[0027] The "magnetic bushings" disclosed herein offer the potential
to provide low friction, relatively smooth movement of weight
plates 51 relative to guide members 60. In particular, since
magnetic inserts 80, 90 operate to maintain gap 85 between weight
plates 51 and guide members 60, contact between weight plates 51
and guide members 60 is substantially reduced, thereby
significantly reducing friction therebetween. Further, although the
outer surface of guide members 60 and inner surface of guide member
bores 61 are preferably smooth and clean, since repulsive magnetic
forces are not noticeably inhibited by slight to moderate dirt
buildup, the time and effort spent cleaning guide members 60 and/or
weight plates 51 may be reduced as compared to conventional weight
lifting machines, potentially saving time and money.
[0028] Referring now to FIGS. 5 and 6, a second embodiment of a
strength or weight training machine 100 is illustrated. Machine 100
includes a frame 120, guide members 160, and a weight stack 150
including a plurality of individual weight plates 151. Machine 100
is operated substantially the same as machine 10 previously
described. Namely, the user of machine 100 selects the desired
amount of weight to be lifted by coupling one or more weight plates
151 to weight selection bar 170 with a pin (not shown). In this
embodiment, the user slides the pin through an aperture 173 in a
particular individual weight plate 151, termed the "pinned" weight
plate 151, and through a mating pin bore 174 provided in weight
selection bar 170. Once the pin is sufficiently inserted through
aperture 173 and mating pin bore 174, the pinned weight plate 151
and each weight plate 151 disposed above the pinned weight plate
151 move with weight selection bar 170. In particular, each weight
plate 151 coupled to weight selection bar 170 moves relative to
frame 120 and guide members 160, the motion guided by guide members
160. However, in this embodiment, guide members 160 are not
disposed through each weight plate 151.
[0029] As best shown in FIG. 6, in this embodiment, each guide
member 160 includes a generally L-shaped cross section having an
inside or stack facing surface 160a and an outer surface 160b
generally opposite surface 160a. In addition, each guide member 160
is positioned a corner 152 of stack 150 and each weight plate 151.
Although stack facing surface 160a of each guide member 160 faces
weight stack 150, it does not contact any of weight plates 151.
Rather, stack facing surface 160a is slightly spaced apart from
corner 152 by a gap 185 therebetween. Guide members 160 serve to
substantially maintain the orientation of stack 150 and
substantially guide the movement of weight plates 151. More
specifically, together, the plurality of guide members 160 form a
structure within which stack 150 of weight plates 151 is
maintained. Unlike guide members 60 illustrated in FIGS. 3 and 4,
guide members 160 shown in FIGS. 5 and 6 are not disposed through
each weight plate 151, but rather are positioned about the outer
corners 152 of the stack 150 of weight plates 151. Although four
guide members 160 are shown in FIG. 6, one generally at each corner
152, in general, any suitable number and location of guide members
(e.g., guide members 160) may be employed.
[0030] Referring still to FIG. 6, each weight plate 151 includes a
selection bar bore 171a that together define a selection bar bore
171 through the entire weight stack 150 that slidingly receives
weight selection bar 170. Each weight plate 151 also includes a
plurality of plate magnetic inserts 180 disposed in recesses 181.
Recesses 181, and hence plate magnetic inserts 180, are positioned
generally at each outer corner 152 of each weight plate 151.
Specifically, a recess 181, including a plate magnetic insert 180,
is placed along the outside surface of each side of weight plate
150 adjacent each outer corner 152. In this particular embodiment,
two recess 181 are positioned along the outside surface of each
side of weight plate 151, resulting in eight recesses 181, each
accommodating a plate magnetic insert 180. However, in general, any
suitable number and location of the plate magnetic inserts (e.g.,
plate magnetic inserts 180) may be provided along the outside
surface of one or more sides of the weight plates (e.g., weight
plates 151).
[0031] In addition, each guide member 160 includes a plurality of
guide magnetic inserts 190 disposed throughout the range of travel
of the weight plates 150 in recesses 191 provided in stack facing
surface 160a of each guide member 160. The magnetic inserts 190 may
be each be one piece that covers the range of travel or may be
multiple pieces spaced over the range of travel. In this particular
embodiment, one recess 191, accommodating one guide magnetic insert
190, is disposed in each leg of each L-shaped guide member 160,
resulting in two recesses 191 and two guide magnetic inserts 190
for each guide member 160.
[0032] Magnetic inserts 180, 190 may be secured within recesses
181, 191, respectively, by any suitable means including without
limitation press fitting, adhesives, weld bead, or combinations
thereof. In addition, recesses 181, 191 may be formed by molding or
casting as part of each weight plate 151 and each guide member 160,
respectively, or machined from each weight plate 151 and guide
member 160. Magnetic inserts 180, 190 may also be integral with
each weight plate 151 and guide member 160, respectively.
Additionally, magnetic inserts 180, 190 do not need to be disposed
in recesses.
[0033] Referring still to FIG. 6, each guide magnetic insert 190 is
generally positioned immediately opposite and facing a
corresponding plate magnetic insert 180. Thus, there is one guide
magnetic insert 190 in stack facing surface 160a for each guide
member 160 for each plate magnetic insert 180 provided on the outer
surface of each weight plate 151 adjacent corner 152. However,
magnetic inserts 180, 190 are spaced apart by gap 185. In addition,
magnetic inserts 180, 190 are oriented within recesses 181, 191
such that common poles in magnetic inserts 180, 190 face each other
across gap 185, resulting in repulsive magnetic forces between
magnetic inserts 180, 190. The repulsion between magnetic inserts
180, 190 tends to maintain gap 185, even as each weight plate 151
coupled to weight selection bar 170 moves relative to guide members
160 and frame 120.
[0034] Still referring to FIGS. 5 and 6, as each weight plate 151
coupled to weight selection bar 170 moves during use of machine
100, repulsive forces between magnetic inserts 180, 190 tend to
maintain physical separation of each guide member 160 and each
weight plate 151, thereby reducing contact and resulting friction
between weight plates 151 and guide members 160. As a result,
weight plates 151 tend to exhibit relatively consistent, stable,
smooth motion relative to frame 20 and guide members 160 during use
of Machine 100. Thus, this configuration of repelling magnetic
inserts 180, 190 in guide members 160 and in weight plates 151 may
also be termed a "magnetic bushing."
[0035] The use of the "magnetic bushings" disclosed herein offer
the potential to provide low friction, relatively smooth movement
of weight plates 151 relative to guide members 160. In particular,
since magnetic inserts 180, 190 operate to substantially maintain
gap 185 between weight plates 151 and guide members 160, contact
between weight plates 151 and guide members 160 is substantially
reduced, thereby significantly reducing friction therebetween.
Further, although stack facing surface of guide members 160 and the
outer surface of corners 152 of each weight plate 151 are
preferably smooth and clean, since repulsive magnetic forces are
not noticeably inhibited by slight to moderate dirt buildup, the
time and effort spent cleaning guide members 160 and/or weight
plates 151 may be reduced as compared to conventional weight
lifting machines, potentially saving time and money.
[0036] In some embodiments, guide members 60 passing through guide
bores 61 in each weight plate 51 (FIG. 4) and guide members 160
positioned adjacent each corner 152 of each weight plate 151 (FIG.
6) may both be incorporated into a single weight machine. In such
embodiments, magnetic inserts 80, 180 in each weight plate and
magnetic inserts 90, 190 in each guide member work together to
substantially maintain the orientation of the weight stack and to
reduce contact and friction between the weight stack and guide
members 60, 160.
[0037] Magnetic inserts 80, 180, 90, 190 may comprise any suitable
magnetic material, including without limitation neodymium, iron, or
the like. Alternatively, inserts 80, 180, 90, 190 may comprise
electromagnets.
[0038] Although the embodiments illustrated herein shown magnetic
inserts 80, 180 disposed in recesses 81, 181 in each weight plate
51, 151, respectively, and magnetic inserts 90, 190 disposed in
recesses 91, 191 in each guide member 60, 160, respectively,
alternatively, each weight plate and guide member may be formed
from a magnetic material, or material capable of being
electro-magnetized, thereby eliminating the need for distinct
magnetic inserts and recesses. For instance, referring to FIG. 7,
an individual weight plate 251 includes a magnetic material (or a
material capable of being electro-magnetized), and two guide
members 260 formed from a magnetic material, or comprise
electromagnets, thereby eliminating the need for distinct magnetic
inserts. The embodiment illustrated in FIG. 7 operates
substantially the same as the embodiment illustrated in FIG. 6. The
repulsive magnetic forces between weight plate 251 and guide
members 260 substantially maintaining gap 285 and the orientation
of weight plate 251 relative to guide members 260.
[0039] In the manner described, embodiments described herein offer
the potential to reduce physical contact and associated friction
between the individual weight plates (e.g., weight plates 51, 151)
and the guide members (e.g., guide members 60, 160) that maintain
the orientation of the weight plates and guide the movement of the
weight plates. In particular, embodiments described herein utilize
magnetic repulsion forces to substantially maintain the physical
separation between the weight plates and the guide members. As a
result, the embodiments described herein offer the potential for
weight machines including magnetic bushings which require less
maintenance, while enabling relatively stable smooth movements
during use.
[0040] It should be appreciated that machine 10 illustrated in
FIGS. 1 and 2 is an exemplary weight lifting machine that includes
a stack of weight plates. In particular, machine 10 is a lat
pull-down machine. However, embodiments described herein may be
used on other weight lifting machines that employ stacks of weight
plates that move as the machine is used. For instance, embodiments
described herein may provide improvements to leg extension
machines, shoulder press machines, bench press machines, and the
like.
[0041] While preferred embodiments have been shown and described,
modifications thereof can be made by one skilled in the art without
departing from the scope or teachings herein. The embodiments
described herein are exemplary only and are not limiting. Many
variations and modifications of the system and apparatus are
possible and are within the scope of the invention. For example,
the relative dimensions of various parts, the materials from which
the various parts are made, and other parameters can be varied.
Accordingly, the scope of protection is not limited to the
embodiments described herein, but is only limited by the claims
that follow, the scope of which shall include all equivalents of
the subject matter of the claims.
* * * * *