GB2406292A

GB2406292A - Weightlifting apparatus

Info

Publication number: GB2406292A
Application number: GB0322474A
Authority: GB
Inventors: Adam Martin Blackwell
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-09-25
Filing date: 2003-09-25
Publication date: 2005-03-30
Also published as: GB0407167D0; GB0322474D0

Abstract

Weightlifting apparatus includes first and second substantially horizontal spotting arms 30, 40 spaced apart for supporting the bar 102 of a barbell 100. The first and second spotting arms 30,40 are capable of vertical motion, preferably independently. The arms may be controlled to operate in an assistance mode in which the spotting arms track and engage the barbell to assist in lifting the barbell; and the spotting arms are arranged to allow the barbell to roll freely horizontally over the spotting arms when the spotting arms are in contact with the barbell in the assistance mode. Also disclosed is an end section (figure 5) for attachment to the ends of a barbell (100) and engagement with spotting arms (30) allowing the barbell to roll over the spotting arms.

Description

WEIGHTLIFTING APPARATUS

The invention relates to weightlifting apparatus and in particular to weightlifting apparatus offering support to users lifting weights.

Weightlifters lifting weights may need m some exercises a spotter or spotters who can provide assistance to help support the bar in case the weightlifter needs it.

This is particularly important in exercises that are performed to the point of fatigue.

US 5,314,394 describes weightlifting apparatus in which a barbell is supported by a support structure that provides variable amounts of assistance. Collars located in the central part of the barbell attach the barbell to a frame connected to a motor which provides the intermittent assistance.

According to a first aspect of the invention there is provided weightlifting apparatus for use with a barbell, comprising: first and second substantially horizontal spotting arms spaced apart for supporting the bar of a barbell, the first and second arms being capable of vertical as motion; at least one motor for driving the first and second spotting argons; .

a controller having inputs from at least one sensor and outputs connected to control the at least one motor arranged to drive the motors to track the barbell with the I . spotting arms; ,. wherein the controller is arranged to operate in an assistance mode in which the spotting arms engage the barbell to assist in lifting the barbell; and the spotting arms are arranged to allow the barbell to roll freely horizontally over the spotting arms when the spotting anus are in contact with the barbell in the assistance mode.

By allowing the barbell to freely move horizontally assistance can be provided without impeding the normal lifting of a weightlifter using the apparatus. Such free horizontal motion is not possible using the arrangement of US 5,314,394 in which the horizontal bar is held in collars that will inevitably give rise to significant frictional resistance.

Preferably, the spotting arms are movable vertically independently of one another and the controller Is arranged to independently control each spotting arm to track the barbell. This ensures that the spotting arms can track and assist even if the barbell is not fully horizontal. In this way it is possible to move the spotting arms against the barbell to provide assistance without causing a strong rotational impulse when the arms hit the barbell even if the barbell is not horizontal.

The spotting arms may be arranged to be rollers of circular section rotatable about the longtudmal axis of the roller. Alternatively, rollers may be provided on the upper surface of the spotting arms. Either way, free horizontal motion can be achieved.

There is preferably also provided at least one sensor for detecting the distance of the barbell above the first and second spotting arms, wherein the controller is arranged to drive the spotting arms in a tracking mode with the spotting arms spaced a predetermined target distance below the barbell.

According to a second aspect of the invention there is provided a weightlifting apparatus, comprising: first and second substantially horizontal spotting arms spaced apart for t. ..

supporting the bar of a barbell, the first and second arms being capable of independent ..

vertical motion; at least one sensor for detecting the distance of the barbell above the first and .

second spotting arms; at least one motor for driving the first and second spotting arms independently; .. and a controller having inputs from the at least one sensor and outputs connected to control the at least one motor arranged to drive the motors to track the barbell with the spotting arms.

The spotting apparatus according to the second aspect of the invention can track the position of the barbell above the arms and accordingly drive the arms to track the barbell. In this way, the lifter can lift the barbell entirely freely without any constraints and the arms can track the barbel] as the lifter carries out the lift. This is further enhanced by the provision of Independently driven arms so that even if one end of the barbell is a little above the other end it is still possible to track the barbell.

In contrast, the collar arrangement of US 5,314,394 constrains the barbell to be horizontal at all times. Further, the barbell cannot move without also moving the tracking mechanism and this inevitably interferes with free lifting.

In either aspect, a number of additional features are useful. The spotting arms are preferably of circular section and are rotatable about their longitudinal axis. This allows the barbell to freely move when resting on the spotting arms.

The apparatus may mclude a ratchet brake for operation in a ratchet mode to allow the spotting aunts to rise but not to fall. The ratchet mode can be engaged on a power failure, by providing a ratchet and an actuator that disengages the ratchet. When the power fails, the ratchet engages and prevents the spotting arms and hence the barbell from falling. The ratchet mode can also be engaged by the computer to brake the spotting arms when required.

The apparatus may also include counterbalance weights connected to counterbalance the weight of the spotting arms. The weight of the weights connected to early spotting arm may be slightly greater than the weight of the spotting arms to provide an upwards bias to raise the arms. This is particularly beneficial in .- combination with the ratchet brake. On power failure, the counterbalance weights raise ..

the arms to engage the barbell which is then prevented from falling by the ratchet brake.

The controller may be arranged to operate selectably in a tracking mode or in an -.

assistance mode, wherein in the tracking mode the spotting arms track the barbell and in the assistance mode the spotting arms engage the barbell to assist in lifting the ,. barbell.

In a tracking mode the spotting arms preferably track the barbell at a predetermined distance from the barbell.

In the assistance mode the controller may be arranged to target a predetermined vertical speed of the barbell. Alternatively or additionally the controller may control the arms to provide a predetermined assistance force. The choice of mode can be done either automatically or under user control.

A frame may be provided having four vertical struts, the spotting arms extending between adjacent pairs of struts. Each end of the spotting arms may be connected to a cable passing over pulleys, the cable passing along the length of the vertical struts. The cable may be driven by a motor. A separate motor may be provided to drive each spotting arm, and separate cables may be used for each end of the spotting arm.

Shock absorbers may optionally be provided either at the pulleys or in the end of the cable to absorb shocks.

The invention also relates to a weightlifting kit including weightlifting apparatus as set out above and a pair of end sections for attachment to the ends of a barbell, the end sections having an outer end section for engagement with the spotting arms.

The outer end section may include a rotary sleeve for free rotation about the axis of the barbell, to allow the barbell to roll over the spotting argons. The perpendicular rotations provided by spotting arms and end sections allow free movement of the barbell in all four horizontal directions.

The end sections may include a disk extending around the end section on the inner side of the rotary sleeve to prevent the end of the barbell from moving outwards past the spotting arms, and to ensure that when the spotting arms are brought into contact with the barbell the spotting arms come into contact with the rotary sleeve to ë allow free horizontal movement. The disks on the pair of end sections effectively ma locate the barbell correctly over the spotting arms. The disks preferably have a sufficient radius to locate the barbell even when the spotting arms are spaced away .- from the barbell by the predetermined tracking distance.

I

Thus, in another aspect, the invention relates to an end section for attachment in pairs to the end of a barbell for engagement with weightlifting apparatus having first ., and second substantially horizontal spotting arms; the end section comprising: an inner end for engagement with the end of the barbell having means for attaching the inner end to the barbell; an outer end longitudinally spaced from the inner end having a rotary sleeve for engagement with a spotting arm, the rotary sleeve being rotatable about a longitudinal axis; and a disk extending laterally between the inner and outer ends for engagement with the spotting arms.

Specific embodiments of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of spotting apparatus according to a first embodiment of the invention; Figure 2 shows a detail view of the spotting arms of the arrangement of Figure 1; Figure 3 shows a detail view of the cable of the arrangement of Figure 1; Figure 4 shows the cable drum and drive of the arrangement of Figure 1; Figure 5 shows a barbell adapted for use with the spotting apparatus of Figure 1; Figure 6 shows a counterbalance system of the arrangement of Figure 1; Figure 7 shows a schematic view of a computer used in the arrangement of Figure 1; and Figure 8 shows a front view of a second embodiment of the invention.

The drawings are purely schematic and not to scale.

Referring to Figure 1, an embodiment of spotting apparatus according to the invention has a frame 10 with four vertical struts 12,14,16,18, one at each corner, held ë . in place by four upper horizontal bars 20 and three lower horizontal bars 22. The ..

entrance side 24 of the frame omits the lower bar so that a weightlifter can get inside the frame wholly unimpeded.

A first spotting arm 30 extends between first and second struts 12,14 on the left side 26 of the frame on one side of the entrance side 24 and a second spotting arm 40 . extends between third and fourth struts 16, 18 on the right side 28 of the frame opposite : the left side.

Figure 1 also shows the barbell 100 supported by spotting arms 30,40. The barbell 100 has grip region 102, weight supporting region 104 of slightly larger diameter carrying weights 105 and outer end pieces 106 resting on the spotting arms 30,40. The barbell and in particular the ends will be described in more detail below with reference to Figure 5.

As illustrated in Figure 2, the spotting anus 30, 40 have a bearing housing 50 at each end which engages a vertical slide shaft 52 which runs vertically at the respective vertical strut 12, 14, 16, 18. The bearing housing has a ball bush 54 including ball bearings to allow free motion of the bearing housing 50 up and down the shaft. The spotting anms 30,40 are accordingly free to move up and down independently, but are constrained to stay horizontal by the ball bush 54 as well as the cables (see below).

The spotting arms in the embodiment are tubular section and are mounted in the bush 50 by rotary bearing 51 to allow rotation of the spotting arm.

S As shown in Figures 2 and 3, a cable 56 is used at each end of the spotting arm 30, 40 and is led through a series of pulleys 58 and around a cable drum 70 having notches 72 (See Figure 4) which locate the cable on the drum 70. The cable is attached to the bearing housing 50 at the end of the spotting and 30,40. The cable is led down and up at each vertical strut 12, 14, 16, 18 at the end of the spotting and and the spotting arm is attached in such a way that it is constrained to remain horizontal but can be raised or lowered by rotation of the cable drum 70.

In the embodiment shown, each end of each spotting arm uses a separate cable 56 but alternatively the two ends of each arm may use a single cable if required.

Separate cables 56 are used for each spotting arm 30, 40 to allow independent motion of the spotting arms.

As shown in Figure 2, the pulley 58 is mounted on a shock-absorbing platform 60 which has a ball bush 62 around the slide shaft 52. The platform is mounted on a - .e shock absorber 64 on a solid platform 66 welded to the frame structure. A force sensor 68 is provided between the pulley and the shock-absorbing platform 60. In an alternative arrangement the shock absorption is provided by a shock absorber where the .

cable 56 meets the bearing housing 50.

One of the pulleys of each cable also includes a rotation sensor 122. This may . be on the same pulley as the load sensor or another pulley. The rotation sensor measures the position of cable 56 and hence of the attached spotting and.

Figure 4 shows the cable drum 70 and cable 56. The cable drum 70 is connected to a brake 74 and to motor 76.

The brake 74 is a ratchet brake commented to electrically operated actuator 75 to disengage the brake biased to engage the brake. In the event of power failure the actuator 75 causes the ratchet brake 74 to engage. In tiers engaged state, the ratchet brake 74 allows the spotting arms to move upwards but prevents downwards motion of the arms. In normal use, with power applied, the brake is disengaged. Thus, in the event of power failure, the brake prevents descent of the barbell and thus avoid possible injury to the user.

Each spotting arm 30, 40 has a separate cable 56, cable drum 70, brake 74 and motor 76 to enable the two spotting arms to be controlled independently.

Figure 5 shows the end of a barbell 100 adapted for use with the invention.

Conventional barbells 100 are known either as "Standard" or "Olympic" barbells - the invention can be used with either, or indeed any other fond of barbell, though the specific embodiment uses an "Olympic" barbell which is the type commonly used in gyms. The barbell has a central grip section 102 (Figure 1), and an outer weights section 104 for supporting weights 105. These features are those of a conventional Olympic barbell, and indeed it is a benefit of the invention that it can be used with existing barbells.

In the embodiment shown, as illustrated in Figure 5, an add-on piece 106 is attached to each end of the existing barbell 100. The add-on piece 106 has an inner end section 108 for surrounding the end of the barbell 100 and a fastening means 1 1 1 for fixing the inner end 108 to the barbell 100. In the embodiment shown, the fastening means 111 is a magnet 111 fixed to the end of shock absorber 110. Although a magnetic fastening might at first sight not be thought of as strong enough, in practice - . most of the stresses at the end of the barbell are compressive so the fastening does not -..

need to be particularly strong. Alternatively, a screw can be used to fix the add-on piece 106 to the barbell 100. -.

At the outer end 1 12 of the add-on piece 106 is provided a rotary sleeve 114 . - ..

arranged to rotate on the outer end 112 on bearings 116. A disk 117 extends around the add-on piece on the inner end of the rotary sleeve 114 to locate the barbell on the .. spotting arms. The disk 117 has a radius greater than the predetermined target distance of spotting arms to barbell in the tracking mode so that the barbell remains located along the length of the barbell even when the barbell is spaced away from the spotting arms.

The distance between the spotting arms 30, 40 is chosen such that the rotary sleeve 114 rests on the spotting arms 30,40. The fact that both the spotting arms 30, 40 and the sleeve 114 rotate allows the barbell to roll easily in the horizontal plane in all directions even when resting on the spotting arms 30, 40. Thus, the arrangement of the invention ensures free horizontal movement.

The barbell 100 has a button 118 used to control the system connected to a radio transceiver 119 for communication. By avoiding cables being connected to the barbell the risk that the cable could become tangled in the barbel] Is avoided.

Retun1ing to Figure 2, part of a light sensor system 80 is provided at each end of the spotting arm 30,40 on the bearing housing 50 for measuring the distance to the barbell 100. At one end, the part is an array of infra-red transmitters and at the other end the part is an array of infra-red receivers. The vertical length of the array is in the embodiment at least l Ocm and the number of elements of the array is sufficient to provide sufficient vertical resolution of height measurement. The system is driven by control electronics 86 (see Fig. 7) which switches on each light transmitter in the array 82 in turn and measure whether the corresponding receiver receives the light. When the barbell is between the transmitter and receiver, the light is occluded. This allows the position of the barbell with respect to the spotting arms to be measured.

A counterbalance system is provided as illustrated in Figure 6 having a counterbalance cable 90 around counterbalance pulleys 92, supporting a counterbalance weight 94, at each end of each spotting arm 30, 40. The counterbalance cable 90 is - connected to the bearing housing 50 to counterbalance the weight of the spotting arms -..

to 30,40.

The counterbalance system has two benefits. Firstly, it reduces the load on the . - motors 76. Secondly, it provides additional safety if power fails. The counterbalance ] . weight is arranged to be slightly heavier than the spotting arms to provide an upwards .. bias. If power fails, the spotting arms are pulled thereby upwards against the underside . of the barbell so that the ratchet brake 74 will then prevent the barbell falling.

The system is controlled by a computer 120 shown schematically in Figure 7.

The computer is connected to the light sensor system 80, rotation sensors 122 attached to each cable to measure the position of the corresponding spotting arm, and the force sensors 68. The computer outputs are connected to both the motor 76 and brake 74. The input from button 118 via transceiver 119 is picked up by central transceiver 124, and a foot pedal 126 is also connected viaacable to the computer. A display 128 and user control such as keypad] 30 are likewise connected to the computer.

The foot pedal 126 has the same function as the barbell button 118 and provides an alternative switch which may in some cases be more accessible to the user.

In use, the system can be used in one of two main modes.

The first mode, a tracking mode, causes the spotting arms to track the bar without making contact. The light sensor system 80 measures the distance of the barbell 100 above the spotting arms and the rotation sensors measure the height of the spotting arms. The computer l 20 calculates continually the height of the barbell 100 above ground from this information and uses the change in height over time to calculate the velocity and acceleration of the barbell relative to ground.

As the user lifts the weight, the weight is free to move in all directions, constrained by the outer limits allowed by the spotting arms and disk. The user can nevertheless lift weights without being impeded at all since the barbell is not in contact with the spotting arms.

In this mode, the spotting arms are arranged to track the barbell, in a preferred embodiment they track the barbell having a target position a predetermined distance below the barbell 100. The skilled person will realise how to program the computer IS with a suitable control loop.

If the user requires assistance, the user can press the button on the barbell or the ..

footpedal and engage a second mode, the assistance mode. I.

Further, the computer 120 tracking the position ofthe barbell can automatically determine if the motion of the barbell during the tracking mode falls outside .- predetermined safe limits of velocity and/or acceleration for the appropriate part of the - - cycle and can automatically activate assistance if required. For example, there is little .. danger m the lifting phase if the barbell is being lifted to fast, so broad limits may be . set for this phase of the cycle, but during the lowering phase of the cycle there is a danger if the barbell is falling too quickly. Therefore, narrow limits of downward velocity can be set to ensure that the barbell does not fall too quickly.

In the assistance mode the barbel] l 00 rests on the spotting arms 30, 40.

Contact between barbell 100 and arms 30,40 only occurs in this mode. In the assistance mode the force sensors 68 measure the load on each cable at each vertical strut the force of each spotting arm 30,40 on barbell l DO is calculated.

In this mode with the spotting arms 30, 40 against the barbell 100 the spotting arms 30,40 can rotate as can the rotary sleeve 114 on the barbell to allow motion in all four horizontal directions with extremely small impedance. The independent motion of the independent spotting antis 30, 40 allows rotation of the barbell about all three axes in space and independent vertical motion of the barbell, subject of course to the assistance provided.

In one mode, the assistance is arranged to move the barbell at a preprogrammable constant velocity up or down and to provide as much or as little assistance as possible to achieve this.

Alternatively or additionally, the assistance mode can provide assistance with a predetermined force upwards being provided from the spotting anus on the barbell.

Additional programming and setup functions may also be provided.

The frame may be provided with a cable support 210. This may be attached to the barbell in the grip region 102 to hold the barbell to allow the end sections to be removed to allow weights 105 to be added to or removed from the barbell.

The use of external end sections allows the use of a conventional barbell without impeding the grip of the user by taking up part of the grip section. In alternative embodiments however the spotting arms can be arranged inside the weights - this can make replacement of the weights easier.

In a second embodiment, shown in Figure 8, the tubular spotting aria 30, 40 is - replaced by a spotting arm of different section, such as box section, with a spotting arm ..e roller 200 on the upper surface to allow the barbell to roll on the spotting arm.

From reading the present disclosure, other variations and modifications will be apparent to persons skilled in the art. Such variations and modifications may involve ..-.

equivalent and other features which are already known in the design, manufacture and . . use of weightlifting apparatus and which may be used in addition to or instead of features described herein. Although claims have been formulated in this application to particular combinations of features, it should be understood that the scope of disclosure also includes any novel feature or any novel combination of features disclosed herein either explicitly or implicitly or any generalization thereof, whether or not it mitigates any or all of the same technical problems as does the present invention. The applicants hereby give notice that new claims may be formulated to any such features and/or combinations of such features during the prosecution of the present application or of any further applications derived therefrom.

Claims

1. Weightlifting apparatus for use with a barbell, comprising: first and second substantially horizontal spotting arms spaced apart for supporting the bar of a barbell, the first and second arms being capable of vertical motion; at least one motor for driving the first and second spotting arms; a controller having outputs connected to control the at least one motor arranged to drive the motors to track the barbell with the spotting arms; wherein the controller is arranged to operate in an assistance mode in which the spotting arms engage the barbell to assist in lifting the barbell; and the spotting arms are arranged to allow the barbell to roll freely horizontally over the spotting arms when the spotting arms are in contact with the barbell in the assistance mode.

2. Weightlifting apparatus according to claim l, wherein the spotting arms are movable vertically independently of one another and the controller is arranged to .e independently control each spotting and to track the barbell. .

3. Weightlifting apparatus according to claim 1 or 2 wherein the spotting arms are 1.-e arranged to have or to be rollers of circular section rotatable about the longitudinal axis . of the roller. - .

4. Weightlifting apparatus according to any preceding claim, further comprising at least one sensor for detecting the distance of the barbell above the first and second spotting arms, wherein the controller is arranged to drive the spotting arms in a tracking mode with the spotting arms spaced a predetermined target distance below the barbell.

5. Weightlifting apparatus according to any preceding claim further comprising a ratchet brake for operation in a ratchet mode to allow the spotting arms to rise but not to fall.

6. Weightlifting apparatus according to any preceding claim further comprising force sensors for measuring the force exerted on the barbell by the spotting arms.

7. Weightlifting apparatus according to any preceding claim further comprising a counterbalance weight connected to counterbalance the weight of the spotting arms.

8. Weightlifting apparatus according to any preceding claim in which the controller Is arranged to target a predetermined vertical speed of the barbell in an assistance mode.

9. Weightlifting apparatus according to any preceding claim in which the controller is arranged to target a predetermined upwards force on the barbel] in an assistance mode.

10. Weightlifting apparatus, comprising: first and second substantially horizontal spotting arms spaced apart for - supporting the bar of a barbell, the first and second anns being capable of independent A. vertical motion; at least one motor for driving the first and second spotting arms independently;

- ë and

a controller having inputs from the at least one sensor and outputs connected to .. control the at least one motor arranged to drive the motors to track the barbell with each . of the spotting arms independently.

11. Weightlifting apparatus according to claim 10 further comprising at least one sensor for detecting the distance of the barbell above the first and second spotting arms, wherein the controller is arranged to drive the spotting arms in a tracking mode with the spotting arms spaced below the barbell and not in contact with the barbell.

12. A Weightlifting kit including Weightlifting apparatus according to any preceding claim and a pair of end sections for attachment to the ends of a barbell, the end sections having an outer end section for engagement with the spotting arms.

13. A weightlifting kit according to claim 12 wherem the outer end section includes a rotary sleeve for free rotation about the axis of the barbell.

14. A weightlifting kit according to claim 12 or 13 further comprising a disc extending from the end sections inwards of the outer end sections for engagement with the spotting arms to act as end stops for horizontal movement of the barbell.

15. An end section for attachment in pairs to the end of a barbell for engagement with weightlifting apparatus having first and second substantially horizontal spotting arms; the end section comprising: an inner end for engagement with the end of the barbell having means for attaching the inner end to the barbell; an outer end longitudinally spaced from the inner end having a rotary sleeve for engagement with a spotting arm, the rotary sleeve being rotatable about a longitudinal axis; and a disk extending laterally between the inner and outer ends for engagement with - .. the spotting arms. A. .

16. Weightlifting apparatus substantially as herein described with reference to and - as shown in the accompanying drawings.

revere . -