AUTOMATIC SPOTTER LIFT FORCE CALCULATOR AND DISPLAY DEVICE AND METHOD OF USE

Abstract

A system for measuring actual weight lifted by a user when a spotting force is applied and calculating a spotting force. The system is comprised of a display device and sensors having strain gauges attached to a weight lifting bar. The system will determine and display the actual weight lifted by a user with or without a spotting force, and a spotting force applied.

Claims

1. A display device for a weight lifting bar comprising: a processor, operatively connected to a memory; a display operatively connected to the processor; a sensor set, positioned on the weight lifting bar, and operatively connected to the processor; the memory including a set of instructions that, when executed, causes the display device to perform the steps of: receiving a first sensor signal set from the sensor set; determining a first exerted force, in a first direction, based on the first sensor signal; receiving a second sensor signal set from the sensor set; determining a second exerted force, in a second direction, based on the second sensor signal; determining a resultant force based on the first exerted force and the second exerted force; and, displaying, on the display, a first value related to the resultant force.

2. The display device of claim 1 wherein the set of instructions further comprises instructions that when executed cause the display device to: display a second value related to the second exerted force.

3. The display device of claim 1 wherein the set of instructions further comprises instructions that when executed cause the display device to: display a second value related to the first exerted force.

4. The display device of claim 1 wherein the sensor set further comprises a first strain gauge and a second strain gauge.

5. The display device of claim 4 wherein the step of determining a first exerted force further comprises summing a signal from the first strain gauge and a signal from the second strain gauge.

6. The display device of claim 1 wherein the step of determining the second exerted force further comprises calculating a difference between the resultant force and the first exerted force.

7. The display device of claim 1 wherein the step of determining the resultant force further comprises calculating a difference between the first exerted force and the second exerted force.

8. The display device of claim 1 further comprising a communication interface, operatively connected to the processor, and wherein the set of instructions further comprises instructions that when executed causes the display device to perform the steps of: transmitting, by the communication interface, the first exerted force, the second exerted force, and the resultant force to an external device; and, displaying, at the external device, one of the first exerted force, the second exerted force, and the resultant force.

9. The display device of claim 1 further comprising a spotter machine, the spotter machine having a cable, connected to the weight lifting bar, and exerting a cable force, and wherein the step of receiving the second sensor signal from the sensor set further comprises receiving the second sensor signal as a result of the cable force.

10. The display device of claim 1 wherein the display device is removably connected to the weight lifting bar at an off center position.

11. The display device of claim 1 wherein: the first sensor signal further comprises a first right sensor signal and a first left sensor signal; and, wherein the set of instructions further comprises instructions that when executed causes the display device to perform the step of: summing the first right sensor signal and the first left sensor signal.

12. The display device of claim 11 wherein: the second sensor signal further comprises a second right sensor signal and a second left sensor signal; and, wherein the set of instructions further comprises instructions that when executed causes the display device to perform the step of: summing the second right sensor signal and the second left sensor signal.

13. The display device of claim 12 wherein the first right sensor signal is about equal to the first left sensor signal.

14. The display device of claim 12 wherein the second right sensor signal is about equal to the second left sensor signal.

15. The display device of claim 11 wherein the resultant force further comprises a left resultant force and a right resultant force.

16. A method of determining forces exerted on a weight lifting bar comprising: providing a processor, operatively connected to a memory; providing a display operatively connected to the processor; providing a sensor set, positioned on the weight lifting bar, and operatively connected to the processor; providing a set of instructions, resident in the memory, that when executed, causes the processor to perform the steps of: receiving a first sensor signal set from the sensor set; determining a first exerted force, in a first direction, based on the first sensor signal; receiving a second sensor signal set from the sensor set; determining a second exerted force, in a second direction, based on the second sensor signal; determining a resultant force based on the first exerted force and the second exerted force; and, displaying, on the display, a first value related to the resultant force.

17. The method of claim 16 wherein the step of providing the set of instructions further comprises providing instructions that when executed cause the processor to: display a second value related to the second exerted force.

18. The method of claim 16 wherein the step of providing the set of instructions further comprises providing instructions that when executed cause the processor to: display a second value related to the first exerted force.

19. The method of claim 16 wherein the step of providing the sensor set further comprises providing a first strain gauge and a second strain gauge.

20. The method of claim 19 wherein the step of determining a first exerted force further comprises summing a first signal from the first strain gauge and a second signal from the second strain gauge.

21. The method of claim 16 wherein the step of determining the second exerted force further comprises calculating a difference between the resultant force and the first exerted force.

22. The method of claim 16 wherein the step of determining the resultant force further comprises calculating a difference between the first exerted force and the second exerted force.

23. The method of claim 16 further comprising the step of providing a communication interface, operatively connected to the processor, and wherein the step of providing the set of instructions further comprises providing instructions that when executed cause the processor to perform the steps of: transmitting, by the communication interface, the first exerted force, the second exerted force, and the resultant force to an external device; and, displaying, at the external device, the first exerted force, the second exerted force, and the resultant force.

24. The method of claim 16 further comprising the step of providing a spotter machine, the spotter machine having a cable, connected to the weight lifting bar and exerting a cable force, and wherein the step of receiving the second sensor signal from the sensor set further comprises receiving the second sensor signal as a result of the cable force.

25. The method of claim 16 further comprising the step of connecting the processor to the weight lifting bar at an off-center position.

26. The method of claim 16: wherein the step of providing the first sensor signal further comprises providing a first right sensor signal and a first left sensor signal; and, wherein the step of providing the set of instructions further comprises providing instructions that when executed causes the processor to perform the step of: summing the first right sensor signal and the first left sensor signal.

27. The method of claim 26 wherein: the step of receiving the second sensor signal further comprises the step of a second right sensor signal and a second left sensor signal; and, wherein the step of providing the set of instructions further comprises providing instructions that when executed cause the processor to perform the step of: summing the second right sensor signal and the second left sensor signal.

28. A display device for a weight lifting bar comprising: a processor, operatively connected to a memory; a display operatively connected to the processor; a sensor set, positioned on the weight lifting bar, and operatively connected to the processor; the memory including a set of instructions that, when executed, causes the display device to perform the steps of: receiving a total weight value, a first distance value, a second distance value, a third distance value and a fourth distance value; receiving a right sensor signal and a left sensor signal from the sensor set; determining a left lifting force associated with the left sensor signal; determining a right lifting force associated with the right sensor value; calculating a first spotter force and a second spotter force based on the total weight value, the right sensor signal, the left sensor signal, the first distance value, the second distance value, the third distance value and the fourth distance value; and, displaying, on the display, at least one of the first spotter force, the second spotter force, the left lifting force and the right lifting force.

29. The display device of claim 28 wherein the step of calculating a first spotter force and a second spotter force further comprises applying the equations: $\mathrm{SFL}=W-\mathrm{LFL}-\mathrm{LFR}+\left(\frac{{\mathrm{LFLd}}_1+{\mathrm{LFRd}}_3-{\mathrm{Wd}}_2}{d_4}\right)$ $\mathrm{SFR}=W-\mathrm{LFL}-\mathrm{LFR}-\mathrm{SFL}$ Where: SFL=the first spotter force; SFR=the second spotter force; W=the total weight value; LFL=the left lifting force value associated with the left sensor signal; LFR=the right lifting force value associated with the right sensor signal; d.sub.1=is a first distance, along the weight lifting bar, between an application of the first spotter force and the application of the left lifting force; d.sub.2=is a second distance, along the weight lifting bar, between the application of the first spotter force and a longitudinal center of weight lifting bar; d.sub.3=is a third distance, along the weight lifting bar, between the application of the first spotter force and an application of the right lifting force; and, d.sub.4=is a fourth distance, along the weight lifting bar, between the application of the first spotter force and an application of the second spotter force.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In the detailed description of the preferred embodiments presented below, reference is made to the accompanying drawings.

[0021] FIG. 1 is a side view of a multi-mode exercise machine in the prior art.

[0022] FIG. 2 is a side view of a multi-mode exercise machine in the prior art.

[0023] FIG. 3 is a side view of a preferred embodiment of a system for measuring alter weight, a spotter force and a resultant weight lifted.

[0024] FIG. 4A is a free body diagram of a preferred embodiment.

[0025] FIG. 4B is a free body diagram of a preferred embodiment.

[0026] FIG. 5A is a schematic diagram of a preferred a system for measuring actual weight lifted, a spotter force and a resultant weight lifted.

[0027] FIG. 5B is a network diagram of a system for measuring actual weight lifted, a spotter force and a resultant weight lifted.

[0028] FIG. 6A is a state chart implemented by a preferred embodiment.

[0029] FIG. 6B is a flowchart of a preferred method for determining an actual weight lifted, a spotter force and a resultant weight lifted.

[0030] FIG. 6C is a flowchart of a preferred method of system startup.

DETAILED DESCRIPTION OF THE INVENTION

[0031] In the description that follows, like parts are marked throughout the specification and figures with the same numerals, respectively. The figures are not necessarily drawn to scale and may be shown in exaggerated or generalized form in the interest of clarity and conciseness.

[0032] Referring then to FIG. 3, the configuration of a barbell with a preferred embodiment of a weight display device attached will be described.

[0033] Barbell 300 is comprised of steel shaft 302. Steel shaft 302 is typically about 5 to 7 feet long having a diameter of approximately 1 inch. The steel shaft includes grip 308 and grip 310. Grips 308 and 310 are typically knurled sections of the bar.

[0034] Barbell 300 is further comprised of sleeve 304 and sleeve 305. Sleeve 304 is connected to end 301 of steel shaft 302. Sleeve 305 is connected to end 303 of steel shaft 302. The sleeves are chrome cylinders coaxial with the steel shaft having a diameter of about 2 inches. Sleeve 304 includes integrally formed collar 309. Sleeve 305 includes integrally formed collar 311.

[0035] In a preferred embodiment, sleeves 304 and 305 include bearings 321 and bearings 322. The bearings allow rotation of the sleeves around steel shaft 302 to reduce friction on the users hands as the bar is rotated about its longitudinal axis. Sleeve 304 and sleeve 305 support weight plate 306 and weight plate 307, respectively.

[0036] Connected to barbell 300 are sensor 312, sensor 314, and display device 316. Display device 316 is comprised of a screen and microcontroller, as will be further described. The display device is positioned off-center on the barbell. In a preferred embodiment, the display device is removably attached to the steel shaft via clip 317. Alternative methods of attaching the display device may be utilized.

[0037] Sensor 312 and sensor 314 each include a strain gauge and are electrically connected to display device 316, as will be further described. In a preferred embodiment, the sensors are removably attached to the steel shaft along grip lines using a suitable industrial adhesive. In alternate embodiments, a single strain gauge may be employed, at either position.

[0038] Barbell 300 may be used with the multi-mode exercise machine disclosed in '612 Patent to Breaux. In this configuration, bar clamp 318 attaches spotter cable 320 to barbell 300 at center line 350.

[0039] It should be noted that while the invention is shown in use with a barbell, it may also be used with other lifting bars or a multi-mode weight lifting machines, such as a trap bar, a log bar, a Swiss bar, a safety squat bar, a cambered bar, a curl bar, or a tricep bar.

[0040] Referring then to FIG. 4A, an example free body diagram 400 representing the forces exerted on barbell 300 during use will be further described.

[0041] In any static situation, the sum of the forces on the free body must equal zero. In this example, lift forces LF1 and LF2 are directed upwards on sensors 312 and 314. LF1+LF2 is equivalent in magnitude, but opposite in direction to the weight of the bar and weights which acts with a downward force W. When a central spotting force, SF, is applied, the free body diagram must still be in equilibrium. Therefore, the sum of forces exerted may be represented by the following equation:

LF1+LF2+SF−W=0

[0042] In this example it is assumed that LF1=LF2. However, it should be appreciated that while the spotting force is depicted as central to the barbell, a spotting force may be applied at one or more positions, such as at either end of the bar. Further, these spotting forces may not be equal. In this case, LF1 may not be equal to LF2 and so the sensors will measure different force values.

[0043] Those of skill in the art will recognize that the forces described may be reversed, such as in the case where the lift force is directed downward, such as in a typical trap exercise on a trap machine.

[0044] Referring then to FIG. 4B, an example of free body diagram 401, representing different forces exerted on barbell 300 during use, will be further described.

[0045] In this example, lift forces LFL and LFR are directed upwards on sensors 312 and 314. Spotting forces SFL and SFR are directed upward. Weight force W, as a result of gravity, is directed downward.

[0046] Force LFL acts at distance d1 from force SFL. Weight force W acts at distance d2 from SFL. Force LFR acts at distance d3 from SFL. Likewise, force SFR acts at distance d4 from force SFL.

[0047] Forces W, LFL and LFR are known. Force W is the total weight of the free weights and the bar combined. Force LFL and LFR are available from force sensors 312 and 314, as will be further described.

[0048] Assuming the known variables, the following equations of motion apply.

ΣF: SFL+LFL+LFR+SFR+W=0

ΣM: SFL(0)+LFL(d.sub.1)−W(d.sub.2)+LFR(d.sub.3)+SFR(d.sub.4)=0

Where:

[0049] d.sub.1=the distance between the application point of SFL and LFL; [0050] d.sub.2=the distance between the application point of SFL and bar center; [0051] d.sub.3=the distance between the application point of SFL and LFR; and, [0052] d.sub.4=the distance between the application point of SFL and SFR.

[0053] Referring then to FIG. 5A, a schematic of a preferred embodiment of display device 500 will be further described.

[0054] Display device 500 is comprised of strain gauge 518 and strain gauge 520 electrically connected to analog amplifier 516. Strain gauges 518 and 520 are located in sensors 312 and 314. In a preferred embodiment, analog amplifier 516 is a high precision load cell weight sensor having two channel input and capable of providing a digital output, such as the HX711 by Avia Semiconductor of China.

[0055] Analog amplifier 516 is further connected to microcontroller 508. Battery 502 is connected to display 506, microcontroller 508 and analog amplifier 516 through voltage regulator 504. In a preferred embodiment, display 506 is a low power LCD, or a super twisted nematic LCD, such as part no. NHD-0208AZ-RN-YBW-33 available from Newhaven Display Intl of Elgin, Ill. However, alternative screen types may be used, such as LED or OLED.

[0056] Microcontroller 508 is comprised of processor 510, memory 512, and communication interface 514. Memory 512 includes an operating system for the micro controller and a set of program instructions, which, when executed by the microcontroller, carry out the functions of the invention. In one embodiment, communication interface 514 includes Bluetooth capabilities to connect with a wireless device, such as a smartphone, as will be further described.

[0057] Microcontroller 508 is also operatively connected to keypad 513. In a preferred embodiment, keypad 513 is a compact alphanumeric keypad, such as keypad switch GS120203 by Storm Interface of Maldon, England.

[0058] Referring then to FIG. 5B, a network diagram for an alternate embodiment of a system incorporating the display device will be further described.

[0059] Display device 500 is wirelessly connected to client device 530. Client device 530 is a smart device such as a smartphone or tablet. In a preferred embodiment, client device 530 includes application 532 which when activated connects the client device to display device 500 via Bluetooth. Client device 530 further comprises onboard display 533 which is controlled by application 532. In this embodiment, data indicating the actual weight, the spotter force and the resultant weight lifted are sent to the client device wirelessly where they are stored and displayed.

[0060] Referring to FIG. 6A, preferred a mode selection state chart will be further described.

[0061] At system start-up, microcontroller 508 enters wait state 605. During wait state 605, microcontroller 508 monitors keypad 513 for entry of a state selection.

[0062] In a preferred embodiment, two-state selections are available, system startup state 601 and run state 603.

[0063] Upon selection of system startup state 601, the processor polls the keypad for data entry, as will be further described. On completion of system startup state 601, the processor returns to wait state 605.

[0064] Upon selection of run state 603, the processor loads and executes a set of instructions that carry out the functions of the device, as will be further described. Upon completion of run state 603, the microcontroller returns to wait state 605.

[0065] Referring to FIG. 6B, run state 603 will be further described.

[0066] At step 602, a force is applied to the bar on each of the left and right sensors.

[0067] Steps 604 through 608 are optional, and are carried out only if, during setup, no total weight amount is entered.

[0068] At optional step 604, the processor reads sensor activity.

[0069] At optional step 606, the processor delays for about five seconds, in order to allow sufficient time for the force on the bar to stabilize between the right and left sensors. Other delay times may be used.

[0070] At optional step 607, the processor reads both right and left sensors from the analog amplifier and converts them to a digital weight measurement value.

[0071] At optional step 608, the processor stores the original weight values for each of the right and left sensors.

[0072] At step 610, a spotter force or spotter forces are applied to the bar.

[0073] At step 611, the processor then again reads the sensor activity.

[0074] At step 612, the processor again delays about five seconds in order to allow the spotter forces to stabilize. Other delay times may be used.

[0075] At step 614, the processor again reads the right and left sensors from the analog amplifier and converts them to a digital weight measurement value.

[0076] At step 615, the processor stores resultant weight values for each of the left and right sensors.

[0077] At step 616, the processor calculates the spotter forces and the left and right lifting forces as may be required. In a preferred embodiment, the following equations are computed to determine the amount of weight lifted with no spotter forces applied.

LFL.sub.1+LFR.sub.1=LFTOTAL

Where:

[0078] LFL.sub.1=left sensor value as weight is lifted with no spotter forces applied; [0079] LFR.sub.1=right sensor value as weight is lifted with no spotter forces applied; and, [0080] LFTOTAL=original weight lifted.

[0081] The following equations are computed to determine the spotter force applied.

LFL.sub.2+LFR.sub.2=LFRESULTANT

Where:

[0082] LFL.sub.2=left sensor value after spotter force is applied; [0083] LFR.sub.2=right sensor value after spotter force is applied; and, [0084] LFRESULTANT=the resulting weight lifted after application of the spotter force.

LFSPOTTER=LFTOTAL−LFRESULTANT

Where:

[0085] LFSPOTTER=spotting force.

[0086] In situations where there are more than one spotting force is applied and the lifting and spotting forces at the sensors differ, the following equations are computed:

Where:

[0087] LFL.sub.1=original left sensor value; [0088] LFR.sub.1=original right sensor value; and, [0089] LFTOTAL=original weight lifted.

[0090] The following equations are computed to determine the spotter forces applied:

[00001]$\mathrm{SFL}=W-\mathrm{LFL}-\mathrm{LFR}+\left(\frac{{\mathrm{LFLd}}_1+{\mathrm{LFRd}}_3-{\mathrm{Wd}}_2}{d_4}\right)$$\mathrm{SFR}=W-\mathrm{LFL}-\mathrm{LFR}-\mathrm{SFL}$

Where:

[0091] SFL=spotter force left; [0092] SFR=spotter force right; [0093] W=weight value retrieved from memory; [0094] LFL=lifting force left; [0095] LFR=lifting force right; [0096] d.sub.1=the distance between the application point of SFL and LFL; [0097] d.sub.2=the distance between the application point of SFL and bar center; [0098] d.sub.3=the distance between the application point of SFL and LFR; and, [0099] d.sub.4=the distance between the application point of SFL and SFR.

[0100] At step 620, the processor sends a signal to the display to indicate the original weight lifted.

[0101] At step 622, the processor sends a signal to the display to indicate the total spotter force. In another embodiment, spotter force for each of the left and right sensors is displayed.

[0102] At step 624, the processor sends a signal to the display to indicate the resultant weight lifted. In another embodiment, the resultant weight lifted at each of the left and right sensors is displayed.

[0103] At step 626, optionally, the processor transmits the display data to the smartphone via communication interface 514.

[0104] At step 628, the smartphone receives the display data through its own communication interface and displays it via application 532.

[0105] At step 630, the processor returns to mode selection.

[0106] Referring then to FIG. 6C, system startup state 601 will be further described.

[0107] At step 650, processor 510 polls keypad 513 for an entry of the total weight of the bar and the weight plate to be lifted by the user.

[0108] At step 652, processor 510 polls keypad 513 for entry of distances d.sub.1, d.sub.2, d.sub.3, and d.sub.4.

[0109] At step 654, the processor returns to wait state 605.