Chest Press Apparatus for Exercising Regions of the Upper Body

1. Field of the Invention

The present invention relates to an apparati for exercising regions of the upper body, and more particularly to an improved chest press exercise machine.

2. Background of the Invention

A variety of exercise machines which utilize resistance or strength training have become very popular in recent years. Such strength machines are often used in place of conventional free weights to exercise a variety of muscles within the human body. Most strength machines are designed with the goal of optimizing resistance training benefits to the user by combining adjustable weight resistance with ease of use, while also attempting to maintain proper biomechanical alignment of the user's joints.

While such machines offer convenience and other benefits to the user in comparison to free weights, conventional designs typically include a frame superstructure for providing symmetrical balance and support for various levers and weight components of the machines. Such conventional frame superstructures generally result in machines that are oversized in height, width, and architecture. In addition, many of such conventional machines may be inconvenient to users performing more than one repetition of an exercise with varying weights, as the user is generally required to be physically removed from the machine in order to place weights on, or otherwise select the desired weight force before performing each set.

Another limitation found in conventional strength machines utilizing selectable weights is the inability of the user to perform high velocity exercises. In such conventional machines the weights have inertial problems at higher speeds which can result in inconsistent resistance through a complete range of motion, therefore, users are encouraged to perform the exercises slowly. Training at lower velocities produces greater increases in muscular force at slow speeds for the user. Therefore, low velocity training only improves an individual's capabilities at slower speeds. In contrast, training at higher contractal velocities produces increases in an individual's muscular force at all speeds of contraction at and below the training velocity. Therefore, high velocity training improves an individual's functional capabilities at normal contractal velocities, i.e. velocities utilized for activities such as golfing and tennis which are more likely to be a part of every day living. Although there are many forms of strength training which allow for higher velocity training, the resistance mechanisms of such equipment generally do not include selectable weights, these devices do not utilize selectable weights as part of their resistance mechanism, and many users prefer training with selectable weights as opposed to other forms of resistance training, for example, resistance bands.

Conventional resistance equipment may also be limited by designs that prevent users from maintaining the proper biomechanical alignment of joints through a complete range of motion. A variety of machines have been proposed to improve the range of motion of the user, in order to make the exercise performed through the range more effective. Such machines are disclosed in, but not limited to, U.S. Pat. Nos. 5,437,589 and 5,273,504. However, the equipment disclosed in such references does not consistently provide proper biomechanical alignment of the user's joints through the complete range of motion.

Therefore, a need exists in the field of resistance training for selectable weight equipment that allows users to maintain the proper biomechanical alignment of joints through a complete range of motion, while performing exercises at high contractal velocities.

In accordance with the invention there is provided a chest press exercise apparatus comprising a selectable weight mechanism and a support mechanism which pivotally supports a pair of four-bar linkage mechanisms. The selectable weight mechanism is disposed in an off-center position relative to the exercise ready seating position of the user, such that the user can readily access and manually adjust/select the degree of weight force from a seated, exercise ready position. The selectable weight mechanism is preferably mounted in a relatively short weight support frame, typically less than about 3.5 feet in height. The four bar linkage mechanisms are pivotally mounted at their rearward ends about axes which are disposed at an angle relative to a horizontal plane, i.e. are tilted relative to vertical, such that a pair of elongated bars of the four bar linkage mechanisms travel in planes which are tilted relative to vertical. A pair of handles are rigidly connected to the forward most bar component of the four-bar linkage mechanisms such that the handles follow the same pivoting movement as the forward most bar component, as the four bar linkage mechanism are pivoted around the rearward mounted, tilted axes. When utilizing a neutral grip the four-bar linkage mechanisms enable the user to maintain the proper biomechanical alignment of the joints. If a horizontal grip is utilized then the tilted axes maintain the proper alignment of the wrists. The tilted planes through which the four bar linkage mechanisms travel enable the handles to travel along a slightly curvilinear outwardly converging path which simulates as natural a human musculoskeletal outward pushing motion as possible. The four bar linkage mechanisms are preferably mounted to an upright support. A cable and pulley are interconnected between the four-bar linkage mechanisms and the shortened selectable weight mechanism such that as the four bar linkage mechanisms are pivoted around their corresponding primary axis the selected weight is pulled through a relatively short vertical path, preferably about 1 foot. The distance between the point where the cables are connected to the four bar linkage mechanisms and the forward most bar of the four bar linkage mechanisms to which the handles are connected is such that the user has increased leverage control over the pulling of the selected weight resistance.

Accordingly, the present invention is directed to a chest press exercise apparatus that includes a base member and a support member extending from the base member. A pair of four-bar linkage mechanisms are supported by the support member. Each of the pair of four-bar linkage mechanisms includes a primary lever arm pivotable about a primary axis and a follower lever arm pivotable about a secondary axis. The primary axes are disposed at an angle with respect to each other. The primary and follower lever arms lie in a common plane tilted at an angle relative to a vertical plane, which vertical plane is perpendicular to a horizontal plane underlying the base member. The apparatus also includes a weight mechanism operatively associated with the pair of four-bar linkage mechanisms. The primary and follower lever arms travel in the common plane as the pair of four-bar linkage mechanisms are displaced between a first position and a second position while maintaining a correct biomechanical positioning of the user.

In another aspect of the invention, the chest press exercise apparatus includes a handle lever arm operatively associated with both of the primary and follower arms of each of the pair of four-bar linkage mechanisms. A handle extends from each handle lever arms, each handle extending outwardly and perpendicularly from the handle lever arm, and curving outwardly and downwardly therefrom at a 90 degree angle. The handles travel in a slightly curvilinear upwardly converging and downwardly diverging path as the four-bar linkage mechanisms are displaced between a first position and a second position, while maintaining the correct biomechanical positioning of the user.

In another aspect of the present invention, the support member includes at least one post member connected to the base member extending upwardly behind a seat. The first and second four-bar linkage mechanisms are supported on the at least one post member above and behind the seat. The primary and follower lever arms travel in the common plane as the four-bar linkage mechanisms are displaced between a first position and a second position.

In another aspect of the invention, the first and second four-bar linkage mechanisms each have a length, and are each pivotally supported at a first selected position along the length, each having a handle connected to a second selected position along the length. The apparatus includes a seat which positions a user in a disposition relative to the handles such that the handles are manually engageable by the user for pushing the handles between the first position and the second position in a chest press motion.

In another aspect of the invention, the chest press exercise apparatus includes a handle lever arm operatively associated with each of the primary and follower lever arms. The handle lever arm includes a manually engageable handle for moving the four-bar linkage mechanisms between the first and second positions. The handle is disposed in a predetermined gripping orientation in the starting position such that the operative association of the handle lever arm with the primary and follower arms maintains the handle extension in the predetermined gripping orientation during displacement of the four-bar linkage arms between the first and second positions.

In another aspect of the invention, at least one of the primary and follower lever arms of each of the four-bar linkage mechanisms is operatively associated with a cable and a selected portion of a selectable weight stack. The selected portion of the weight stack is displaced by a distance upon movement of the four-bar linkage arms from a first position to a second position.

In another aspect of the invention, the primary and follower lever arms each have a length, and a handle interconnected to a first position along the length of at least one of the four-bar linkage mechanisms. The cable is interconnected to a second position along the length of at least one of the four-bar linkage mechanisms. The first and second interconnection positions of the handle and the cable are selected such that the handle travels through a distance less than about 60% of the displacement distance of the selected portion of the weight stack upon displacement of the four-bar linkage mechanisms from a first position to a second position .

FIG. 1 is a front-right perspective view of a chest press exercise apparatus according to the invention;

FIG. 2 is a front view of the FIG. 1 apparatus showing the laterally connected weight stack in a semi-perspective disposition;

FIG. 3 is a left-front perspective view of the FIG. 1 apparatus showing a detail close-up of the control support bar relative to the user seat;

FIG. 4 is a right-front perspective view of the FIG. 1 apparatus showing a detail of the interconnection of cables to the four-bar linkage arms;

FIG. 5 is a front-right perspective view of the FIG. 1 apparatus showing a user seated in an exercise chest press ready position;

FIG. 6 is a perspective view of the pivotally mounted portion of one of the pair of four-bar linkage arms of the FIG. 1 apparatus;

FIG. 7 is a right side view of the rear-upper portion of the FIG. 1 apparatus showing the tilted pivot axis mounting of one of the four-bar linkage arms to the central support bar member of the FIG. 1 apparatus;

FIG. 8 is a left side view of the rear-upper portion of the FIG. 1 apparatus showing the tilted pivot axis mounting of one of the four-bar linkage arms to the central support bar member of the FIG. 1 apparatus;

FIG. 9 is a front view of the FIG. 1 apparatus showing a user seated in and grasping a horizontal extension of the handle bars of the FIG. 1 apparatus in a starting chest press exercise position;

FIG. 10 is a front view of the FIG. 1 apparatus showing a user seated in and grasping a horizontal extension of the handle bars of the apparatus in a second extended four-bar linkage arm pivoted position;

FIG. 11 is a left-side perspective view of the FIG. 9 view;

FIG. 12 is a left-side perspective view of the FIG. 10 view;

FIG. 13 is a front view of the FIG. 1 apparatus showing a user seated in and grasping a vertical extension of the handle bars of the FIG. 1 apparatus in a starting chest press exercise position;

FIG. 14 is a front view of the FIG. 1 apparatus showing a user seated in and is grasping a vertical extension of the handle bars of the apparatus in a second extended four-bar linkage arm pivoted position;

FIG. 15 is a side schematic view of an arrangement of interconnected levers which interconnect a foot pedal to the pivotable four-bar linkage arms for initially positioning the four-bar linkage arms;

FIG. 16 is a top right-side perspective view of the upper-side of the central support bar of the FIG. 1 apparatus showing the pivot mounting brackets and pivot wheel stop mechanisms;

FIG. 17 is an upper right-side perspective view of the FIG. 1 apparatus without the seat and base components showing the four-bar linkage arms in an extended pivoted position and showing the interconnection and positioning of the cable and pulleys between the four-bar linkage arms and weight stack.

Referring initially to FIGS. 1, 2, and 17, there is illustrated a perspective and a front view of a chest press exercise machine 10, according to one embodiment of the present invention. Chest press exercise machine 10 preferably includes a support 18 for supporting a pair of four-bar linkage mechanisms 14a and 14b as well as for supporting a seat 20, a selectable weight mechanism 12 operatively connected to each of the pair of four bar linkages 14a and 14b, and a pair of handles 16a and 16b extending from the four bar linkages 14a and 14b, respectively. For purposes of the present description, reference signs with the "b" suffix designate mirror images of those with an "a" suffix.

In the present embodiment, support 18 is preferably constructed of a rigid material such as steel, and includes a base member 19, a pair of post members 21a and 21b (FIG. 17), a cross bar assembly 62, and a pair of extensions 23a and 23b, all of which combine to form the structural elements of support 18. Base member 19 preferably includes a first support member 19a, a second support member 19b and a mounting member 19c disposed therebetween. First and second support members 19a and 19b preferably rest on a substantially horizontal, flat surface, such as the floor 17. Preferably a foot start 15 is located adjacent first support member 19a so that a user can easily grasp handles 16a and 16b in order to begin exercising, as described in greater detail herein below. In the present embodiment mounting member 19c is preferably supported at one end by first support member 19a, is supported at an opposite end by second support member 19b, and is preferably spaced from and substantially parallel to the floor 17.

With continued reference to FIGS. 1, 2, and 17, post members 21a and 21b preferably extend at an angle, which is approximately 30.degree. from vertical axis "v" (FIG. 2) in the present embodiment, and operate to support seat 20 in a reclined position. Cross bar assembly 62 preferably includes a mounting post 62a and a pair of cross bar members 62b and 62c mounted transverse to and preferably at an angle with respect to mounting post 62a. Extensions 23a and 23b are preferably mounted to and extend from post members 21a and 21b, respectively. In the present embodiment, extensions 23a and 23b extend from post members 21a and 21b at an angle which is inclined toward the forward facing direction of the user. It will be understood to one of skill in the art that any number of structural elements, having a variety of shapes, sizes and orientations, may be utilized to form support 18, as long as the structural orientation supports the four bar linkages as the user exercises against a selected resistance.

Referring again to FIG. 1, seat 20 preferably includes a seat cushion 25 and a support cushion 27, is supported in a reclined position, and is preferably adjustable between a plurality of vertical positions. Seat cushion 25 is supported by an angled seat mount 29 while support cushion 27 is supported by angled post members 21a and 21b. Seat 20 is mounted at an angle, which is approximately 30.degree. in the present embodiment, with respect to a plane perpendicular to floor 17, so as to properly orientate the user for performance of a chest press exercise motion. In the present embodiment, adjustment of seat 20 is preferably enabled through a four-bar, gas-assist seat adjustment, although other methods of adjustment, for example hydraulic, may be utilized. A pin 33 is insertable through each of a plurality of holes, in order to select the desired height of the seat. As with support 18, seat 20 may be designed in a variety of configurations and dimensions, and may, or may not be adjustable.

Referring to FIGS. 1, 15, and 16, foot start 15 is preferably located adjacent seat 20, and when activated by a user, allows the user to easily grasp handles 16a and 16b in order to begin exercising, as is known in the art. Foot start 15 preferably includes an engagement rod 15a mounted to a first, forward end of assist lever 15b such that engagement of rod 15a by a user in the direction of arrow "G" moves the first end of assist lever also in the direction of arrow "G". Assist lever 15b is connected at a second end, opposite the first end, to one end of linkage 15c, by pin 15d, such that upon engagement of rod 15a by the user in the direction of arrow "G", linkage 15c moves in the direction indicated by arrow "H". Assist lever 15b is further connected to support 18 by pivot 15e. Linkage 15c is, in turn, connected an opposite end to center link 15f by pin 15g, such that movement of linkage 15c in the direction of arrow "H" pivots center link 15f in the direction indicated by arrow "I". Center link 15f is connected to support 18 by rod 15h, and is connected at a second end to bar 15g, such that pivoting center link 15f in the direction of arrow "I", moves bar 15g in a downward direction as indicated by arrow "J". The movement of rod 15g in the direction of arrow "J" moves rockers 15i and 15j and hence axes 15k and 151 which are connected thereto, in the direction of arrow "M". Axes 15k and 151 are, in turn, rotationally connected to corresponding stop arms 35a and 35b mounted thereto, with rollers 37a and 37b of stop arms 35a and 35b abutting corresponding primary lever arms 36a and 36b (FIGS. 4 and 6). Movement of axes 15k and 151 therefore moves stop arms 35a and 35b, and rollers 37a and 37b, in the direction of arrow "N" to move the four bar linkages 14a and 14b toward the user until the user is able to grip the handles 16a and 16b.

With continued reference to FIGS. 1 and 2, selectable weight mechanism 12 is preferably a high-mass, short-travel (HMST) weight stack. The high-mass, short-travel weight mechanism 12 provides the user with a higher mass weight stack and a shorter range of travel than conventional weight stacks. By increasing the mass and decreasing the range of travel, the speed of the selected weight is decreased during use, without slowing down the speed of the user, as described hereinbelow. This allows an individual to utilize strength training to train at higher contractal velocities s without the associated negative inertial effect found in conventional selectable weights, because as the speed of the weight is decreased, so is the negative inertial effect. Overcoming the negative inertial effect, in turn, results in smooth and predictable resistance through a complete range of motion.

As shown in FIGS. 2 and 5, selectable weight mechanism 12 is preferably disposed in an off-center position relative to the exercise ready, seating position of the user such that the user can readily access and manually adjust/select the degree of weight force from a seated, exercise ready position. In the present embodiment, weight mechanism 12 stands approximately 35 inches in height and preferably includes a housing 22 and a plurality of selectable weight plates 24 supported therein. Housing 22 is preferably supported by a stabilizer bar 22a and brace 22b which are both attached to support 18. The total number of selectable weight plates 24 supported within housing 22 are referred to collectively as a "weight stack." In the present embodiment, weight plates 24 are each approximately 0.75 inches thick and are uniform in weight, each plate weighing approximately 20 lbs. A top weight plate 28 is operatively connected to a cable 30 and a central rod 32. The central rod 32 extends in a downward direction from top weight plate 28 through each of the consecutive weight plates 24. A pin 34 (FIG. 10) is insertable through a transverse hole in each plate, and into the central rod to select the desired amount of weight for the exercise routine to be performed, as is known in the art. Weights 24 are movable in a first and second substantially vertical direction along guide rods 26a and 26b, respectively, as will be described in greater detail herein below.

With reference to FIG. 12, in the present embodiment, the selectable weight plates 24 preferably have a total mass of 400 lbs, which is twice the conventional mass (200 lbs) utilized with a chest press machine. Also in the present embodiment, the selected weight plates 24 travel at approximately half the speed of a selected weight plate of a conventional chest press machine, therefore, the selected weight also is subjected to approximately half the acceleration over approximately half the distance of a conventional selected weight plate utilized with a chest press machine. As shown in FIGS. 11 and 12, the distance "W" that the selected weight plates travel is approximately 55% of the distance "DC" traveled by a user's hand, in the present embodiment, as measured by the distance between the vertical positions of handles 16a and 16b at the start and stop of the exercise. The distance "DC" is a function of the length of the user's arm. The distance a user's hand travels from the beginning to the end of one repetition of the exercise defines a complete range of motion. Although the mass is doubled, the total load the user feels during the performance of an exercise routine is the same as with a conventional chest press machine. This effect is achieved by changing the mechanical advantage to increase the leverage the user has over the selected weight plates from 1.8:1 (force exerted by user:weight) in a conventional system, to a 0.9:1 ratio in the present embodiment. The ratio may be changed by attaching cable 58 (FIG. 17) at an appropriate attachment point along primary lever arm 36a and 36b, in the present embodiment, as determined by conventional engineering techniques.

Referring now to FIGS. 4, 6, and 17, pulley blocks 17a and 17b preferably attach cable 58 at a point approximately mid-way between first pivot points 44a and 44b and second pivot points 46a and 46b of primary lever arms 36a and 36b, respectively. Pulley blocks 17a and 17b are attached at approximately 55% of the distance between first pivot points 44a and 44b and second pivot points 46a and 46b, as measured starting from the second pivot points 46a and 46b, in the present embodiment. The total distance between the pivot points is in the range of approximately 25 to 35 inches, and is approximately 30.5 inches in length in the present embodiment. It should be understood that the placement of cable 58 depends upon the desired leverage, and the desired leverage depends upon the percentage increase in the mass of the weights, as compared to conventional weights. The criteria for determining the placement of cable 58 is that while performing an exercise on the chest press exercise apparatus of the present invention, the user should feel a resistance comparable to that felt while performing an exercise on a conventional chest press exercise apparatus while being able to exercise at higher contractal velocities. The increase in mass is, in turn, determined by several considerations, such as cost, structural load placed on the apparatus by the mass, as well as the ability to readily achieve the desired leverage for a given mass.

With reference to FIGS. 1, 2 and 4, four bar linkage mechanisms 14a and 14b having a length "L", are pivotally mounted at their rearward ends to support 18, and are operatively associated with the selectable weight mechanism 12, as will be described in greater detail herein below. Four bar linkages 14a and 14b are symmetrical in construction, therefore, the below detailed description of linkage 14a is applicable to symmetrical linkage 14b as well. Four bar linkage 14a preferably includes primary lever arm 36a, a follower lever arm 38a, a handle lever arm 40a, and a support arm 42a. Preferably, the primary and follower lever arms lie and travel in a common plane which is tilted at an angle relative to a vertical plane, where the vertical plane is perpendicular to horizontal plane "A" underlying the base 19 of the apparatus. In the present embodiment, for ease of illustration, the tilted common plane is illustrated as plane "T" (FIG. 1), which is tilted with respect to the vertical plane "Z", where plane "Z" intersects the y- axis, and is perpendicular to plane "A", and where the y- axis bisects the seat 27. Although the common titled plane "T" is illustrated with reference to the vertical plane "Z", any vertical may be used as a reference plane for the angular disposition of the four-bar linkages, provided such plane is perpendicular to the horizontal plane "A" underlying the apparatus, and on which it is supported, such as, for example, plane "B".

The primary lever arm 36a is preferably an elongated bar which is pivotally connected at a first, forward end to the handle lever arms 40a, by a pin 44a (FIG. 7) and is pivotally connected at second, rearward end, opposite the first end, by primary axle 46a (FIG. 6), which is axially disposed about primary axis 47a (FIG. 4). The primary axle 46a is, in turn, mounted to the support arm 42a. In the present embodiment, the support arm 42a preferably includes a plate 43a, having a stop arm 35a mounted thereto. The stop arm 35a includes a roller 37a which engages primary lever arm 36a when the machine 10 is not in use, limits the downward movement of four bar linkages 14a and b in the direction of arrow "E", and assists in the grasping of handles 16a and 16b, as described hereinabove.

Follower lever arm 38a is likewise preferably an elongated bar which is pivotally connected at one end to handle lever arm 40a at a first pivot point 48a, by any suitable fastening device, such as a bolt, and is pivotally connected at its opposite, rearward end by secondary axle 50a (FIG. 4), which is axially disposed about secondary axis 51a. The secondary axle 50a is, in turn, mounted to the support arm 42a. The distance between the first pivot point 48a and the second pivot point 50a of follower lever arm is preferably equal to the distance between the pivot points of the primary lever arm. In the present embodiment the distance between pivot points 48a and 50a of follower lever arm is approximately 30.5 inches, although alternate lengths are acceptable for both the primary and follower lever arms. In the present embodiment, the distance between primary axle 46a and secondary axle 50a is 3.75 inches. Also in the present embodiment, secondary axle 50a is mounted to block 52a (FIG. 2) which is part of support arm 42a. Block 52a is preferably welded to a support arm 42a, but may be attached in any suitable manner as long as block 52a remains stationary while supporting follower lever arm 38a. Alternatively, secondary axle 50a may be directly mounted to support arm 42a.

In the present embodiment, the primary axes 47a and 47b are preferably disposed at an angle with respect to a horizontal plane "A" underlying machine 10. Angle .theta. is the angle disposed between the angled primary axes 47a and 47b and is in the range of 135 to 165 degrees, and is preferably 150 degrees for a chest press machine according to the present embodiment. The primary concern with regard to the angle .theta. is that convergence take place in the upward, or pushing direction. In determining the preferred angle employed, several considerations are taken into account, including, but not limited to, the starting and ending points of a handles 16a and 16b (FIG. 1), which allows the correct biomechanical positioning of the user's wrists and forearms to be maintained. "Proper" or "correct biomechanical positioning," as used herein, means that the orientation of the user's wrist and forearm remains relatively constant from the start to finish of a chest press exercise motion, i.e., throughout a complete range of motion. This may also mean that it is not necessary for the user to adjust their hand position on the handles while exercising, since the handles do not twist, as in conventional exercise machines. These points help determine the maximum angle .theta., or in other terms, the maximum upward convergence of the four bar linkages 14a and 14b. In the present embodiment, the secondary axles 50a and 50b are preferably spaced from and are parallel to the primary axles 46a and 46b. The primary axes 47a and 47b are also preferably disposed parallel with respect to a plane "B", plane "B" being perpendicular to horizontal plane "A" (FIG. 2).

With continuing reference to FIGS. 1 and 2, the handle lever arm 40a is the forward most component of the four bar linkage 14a. The handle lever arm 40a is approximately 4.5 inches in length between the pivot points 44a and 48a includes a handle 16a extending therefrom. In the present embodiment, the follower lever arm 38a is preferably not disposed parallel with respect to primary lever arm 36a. The handle 16a is preferably rigidly connected to the handle lever arm 40a, and preferably includes a first handle portion 16x extending in a first, perpendicular direction therefrom, and a second handle portion 16y curving outwardly from the first portion 16x, preferably at a 90.degree. angle, and preferably slightly downwardly. Such an arrangement enables a slight rotational movement of the bottom end 41a of the handle lever arm 40a in the direction of arrow "y" during operation, resulting in a slight tilt of the handle 16a through the complete range of motion. Such a slight tilt of the handle assists the user in maintaining the proper biomechanical alignment of the user's wrist and forearm during performance of the exercise, as previously described. The handle 16a is preferably rigidly connected to the handle lever arm 40a, extends in a first, perpendicular direction therefrom, curves outwardly, preferably at a 90.degree. angle, and preferably slightly downwardly. With such an arrangement, a user may choose either a grip which is perpendicular or substantially parallel to the handle lever arm 40a, also known as horizontal or neutral grips, respectively. When a horizontal grip is used, i.e. when the user grasps handle portions 16x so that their hands are substantially perpendicular to the handle lever arm 40a, as shown in FIGS. 7 and 8, then the tilted axes maintain the correct biomechanical alignment of the wrists. When a neutral grip is used, i.e., when the user grasps handle portions 16y so that their hands are substantially parallel to handle lever arm 40a, as shown in FIGS. 9 and 10, the four-bar linkage mechanisms also enable the user to maintain the correct biomechanical alignment of the joints. In either case, the handle does not substantially twist or change orientation relative to the horizontal (A) and vertical (Z and B) planes throughout the user's complete range of motion, i.e., displacement of the four-bar linkage mechanisms. Alternatively, the handle 16a may extend at any orientation with respect to the handle lever arm 40a, provided the orientation allows the user to comfortably grip the handle while preferably properly aligning the user's hands with respect to the user's wrists. In the present embodiment the handle 16a is welded to the handle lever arm 40a, although other attachment methods may be utilized provided that the handle 16a remains substantially stationary with respect to the handle lever arm 40a. The handle 16a is also preferably covered with foam for user comfort.

Referring now to FIG. 17, pulley system 56 preferably includes a cable 58 attached at a first end to primary lever arm 36a and attached at a second end to primary lever arm 36b. In the present embodiment, the cable 58 is preferably attached by pivot blocks 17a and 17b to both of the primary lever arms 36a and 36b, respectively. As previously discussed, the cable 58 is attached at approximately 55% of the distance between the first pivot points 46a and 46b to the second pivot points 44a and 44b, respectively, as measured starting from the second pivot points 46a and 46b, in order to increase the mechanical advantage the user has over the weight to be lifted.

In order to effectuate movement of the selected weight by actuation of either, or both four bar linkages, cable 58 is routed from primary lever arm 36a, through a plurality of secondary pulleys 61a, 61b, and 61c, respectively, and through floating pulley 60. From floating pulley 60, the cable 58 is routed through a plurality of secondary pulleys 61d, 61e, and 61f for attachment to primary lever arm 36b. Secondary pulleys 61a through 61f operate to route the cable from attachment to the four linkages to the floating pulley 60 in an unobtrusive manner which is easy to access for replacement or repairs, while not interfering with the exercise motions of the user. It will be understood to those skilled in the art that because pulleys 61a through 61f are utilized to route the cable 58 to the floating pulley 60, any number of pulleys may be utilized in a variety of orientations, as long as routing to the floating pulley is achieved.

Floating pulley 60 preferably consists of a pulley 60a disposed between two side plates 60b and, 60c, is connected to a pivot block 63 at one end thereof, and is movable by cable 58 in the direction indicated by arrow M. In operation, a user will begin from a starting position, as shown in FIG. 9, and push on handles 16a and 16b, either simultaneously, or one at a time, in an outward direction, indicated by arrow "E". If the handles are pushed on simultaneously, as shown in FIG. 10, both primary lever arms 36a and 36b operate to put cable 58 in a state of tension, which in turn puts tension on floating pulley 60. The tension on pulley 60 is sufficient to move the pulley in the direction of arrow M, from an initial, at rest position, to a second, active position. Alternatively, if the user chooses to push on only one handle at a time, for example, handle 16b, then the cable is initially moved in the direction of arrow "D" (FIG. 17), as described below.

Movement of handle 16b, and hence, cable 58 in the direction indicated by arrow "D" places tension on the cable, and the tension on the cable is initially transferred to primary lever arm 36a. During movement of handle 16b, handle 16a is preferably still grasped by the user. Therefore, the force initially transferred to primary lever arm 36a will not operate to move the lever arm, as the movement will be resisted by the user's grip on handle 16a. Alternatively, if the user does not resist the force from cable 58, the primary lever arm will move in the direction of arrow "F", until such time as roller 37a of stop arm 35a abuts primary lever arm 36a, as described above. In either case, the force exerted on and through cable 58 will ultimately be transferred through floating pulley 60 and will operate to move pulley 60 in the direction of arrow M, as discussed above. The above description is also applicable to movement of handle 16a, with the force being initially transferred to primary lever arm 36b. It will be understood to those skilled in the art that since the pulleys are utilized to route the cable 58 to the floating pulley 60, any number of pulleys may be utilized in a variety of orientations, as long as routing to the floating pulley is achieved.

Floating pulley 60 is attached at one end to cable 30 by pivot block 63. Movement of floating pulley 60 in the direction of arrow M, therefore, also operates to move cable 30 in the direction of arrow M. As shown in FIG. 1, cable 30 is routed through a pulley 68a, and then through pulley 68b, attached to the exterior of weight mechanism 12. Cable 30 is then received within housing 22 of weight mechanism 12, where the cable is preferably routed through pulleys 70a and 70b (FIG. 17). Pulleys 70a and 70b operate to orientate the cable above the plurality of selectable weights 24, disposed within housing 22. Cable 30 exits the housing at an aperture 72 where it is operatively connected to central rod 32, as described above. Again, any number of pulleys may be utilized to route cable 30, as long as the cable is operatively connected to central rod 32.

The operation of chest press machine 10 will now be described with reference to FIGS. 1-17. Prior to performance of an exercise routine, a user will first adjust seat 20 to a desired position in which the user's feet will preferably be in contact with floor 17. The user then selects the desired weight for performance of the exercise by inserting pin 34 into the transverse hole of the appropriate weight plate, as described above. Due to the off-center orientation of weight mechanism 12 with respect to seat 20, the user may select the weight from either a seated or a standing position. In either case, after the weight has been selected the user should be seated in seat 20 with the user's back preferably resting against support cushion 27. The direction the user is facing is considered the forward facing direction for purposes of this invention. After the user is properly seated, the user pushes on foot start 15, with his or her foot in order to move the four bar linkages and hence handles 16a and 16b toward the user so that the user can readily grasp either one, or both, handles 16a and 16b. Once the user has grasped the handles 16a and 16b, in either a horizontal or neutral grip, the user is ready to perform a chest press exercise. As stated above, when utilizing a neutral grip (FIG. 13 and 14) the four-bar linkage mechanisms enable the user to maintain the proper biomechanical alignment of the joints. If a horizontal grip (FIG. 9 and 10) is utilized then the tilted axes maintain the proper alignment of the wrists.

The user performs the chest press exercise by first pushing on handles 16a and 16b in an outward direction as indicated by arrow "X" (FIGS. 12). As the user begins pushing in the direction as indicated by arrow "X", the bottom end 41 of handle lever arm 40a begins to rotate slightly in the direction of arrow "Y" which results in a slight tilt of handles 16a and 16b through the range of motion of the exercise, but not as much tilt as the angular deflection of primary arms 36 and 36b. This, slight tilt is enabled by the four-bar linkage mechanisms 14a and 14b in order to maintain proper biomechanical alignment of the user's wrist and forearm during performance of the exercise.

As the user continues to move the handles 16a and 16b in the outward direction, because of the orientation of the primary axes 46a and 46b and the secondary axles 50a and 50b, the four-bar linkage mechanisms 14a and 14b travel in planes which are tilted relative to vertical and are, therefore, non-perpendicular with respect to the plane "A" underlying the machine 10, as described herein above. The tilted planes through which the four bar linkage mechanisms travel enable the handles 16a and 16b to travel in a slightly curvilinear upwardly converging and downwardly diverging path, which is illustrated as "C" in FIG. 11. Such a movement simulates as natural a human musculoskeletal outward pushing motion as possible while maintaining proper biomechanical alignment of the user's joints. As the user is pushing the handles 16a and 16b in the outward direction, cable 58 is placed in a state of tension and floating pulley 60 is moved into the active position, as described above. Activation of floating pulley 60 operates to move the selected weights vertically, in an upward direction within housing 22. Once the user has fully extended his or her arms as shown in FIG. 10, the user then allows handles 16a and 16b to return the handles to the starting position for the exercise.

The handles 16a and 16b move along the same path of travel, but in the downward direction, until the handles are returned to the starting position. As the user allows the handles to move toward the starting position, the four-bar linkages travel through the tilted planes once again, this time in the inward direction with respect to the user. While the user is allowing handles 16a and 16b, to return to the start position, the selected weights are moving in a vertical, downward direction, within housing 22. Once the user reaches the starting point of the exercise, one repetition has been completed through the range of motion of the user.

It will be understood that various modifications may be made to the embodiment disclosed herein. For example, all lengths and angles given are approximate and may be varied by one of skill in the art, the machine may be utilized with, or without a high-mass, short-travel weight stack, the machine may be utilized with or without a seat, the primary lever arms may be parallel without substantially effecting the biomechanical alignment of the user's joints. Therefore, the above description should not be construed as limiting, but merely as exemplifications of a preferred embodiment. Those skilled in the art will envision other modifications within the scope spirit of the invention.