US3637204A

US3637204A - Pole vault crossbar apparatus

Info

Publication number: US3637204A
Application number: US84820A
Authority: US
Inventors: Theodore R Dawson
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-10-28
Filing date: 1970-10-28
Publication date: 1972-01-25
Anticipated expiration: 1989-01-25

Abstract

A crossbar for pole vaulting is placed on pegs mounted for vertical travel on two standards. The pegs are moved upward by halyards attached to the pegs and run over wheels at the top of the standards or downward by downhauls attached to the pegs. Therefore, the crossbar may be replaced when the pegs are at a height which is conveniently reached by attendants. The pegs and the crossbar are then raised to the desired height and stopped when protuberances on the halyards engage adjustable stops on the standards. For automatic operation, an electrically conductive crossbar for pole vaulting is set upon pegs which are mounted for vertical travel on the two standards. If the bar is knocked off, the change in electrical resistance between the pegs is noted and the pegs run down the standards so the crossbar is manually replaced on the pegs at which time the change in electrical resistance between pegs cause the pegs to be run up the standards. The height the pegs reach on the standard is adjusted by a limit switch on the standard.

Description

United States Patent Dawson [451 Jan. 25, 1972 [541 POLE VAULT CROSSBAR APPARATUS Theodore R. Dawson, 3794 Blossom Lane, Odessa, Tex. 79760 [22] Filed: Oct. 28, 1970 [21] Appl.No.: 84,820

[72] Inventor:

Related US. Application Data [63] Continuation-impart of Ser. No. 738,952, June 21,

1968, abandoned.

(52] US. Cl. ..272/59 C [51] Int. Cl A63b 5/02, A63b 5/16 [58] Field 0! Search ..272/59 C [56] References Cited UNITED STATES PATENTS 1,388,821 8/1921 Pulliam ..272/59 C 1,887,033 11/1932 Merriman ...272/59 C 1,737,108 1 H1929 Craig ..272/59 C 3,294,400 12/1966 Goldstein 272/59 C Primary Examiner-Richard C, Pinkham Assistant Examiner-Richard Dror Attorney-Charles W. Coffee [57] ABSTRACT A crossbar for pole vaulting is placed on pegs mounted for vertical travel on two standards. The pegs are moved upward by halyards attached to the pegs and run over wheels at the top of the standards or downward by downhauls attached to the pegs. Therefore, the crossbar may be replaced when the pegs are at a height which is conveniently reached by attendants. The pegs and the crossbar are then raised to the desired height and stopped when protuberances on the halyards engage adjustable stops on the standards.

For automatic operation, an electrically conductive crossbar for pole vaulting is set upon pegs which are mounted for vertical travel on the two standards. If the bar is knocked off, the change in electrical resistance between the pegs is noted and the pegs run down the standards so the crossbar is manually replaced on the pegs at which time the change in electrical resistance between pegs cause the pegs to be run up the standards. The height the pegs reach on the standard is adjusted by a limit switch on the standard.

16 Claims, 9 Drawing Figures ageanzcm PATENTEU JAMES m2 SHEEI 1 BF 5 INVENTOR THEODORE R, DAWSON PATENTEDJAN2519I2 31 37l204 INVENTORZ TH EODORE R. DAWSON FIG. 4

INVENTOR: THEODORE R DAWSQN PATENIEU JANZBIHYZ mm-W INVENTOR: THEODORE R. DAWSON POLE VAULT CROSSBAR APPARATUS CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of my copending application entitled AUTOMATIC-SET POLE VAULT CROSSBAR, filed June 21, 1968, Ser. No. 738,952, now abandoned.

BACKGROUND OF THE INVENTION 1. Field'of the Invention This invention relates to pole vaulting and more particularly to setting the crossbar at the desired height.

2. Description of the Prior Art As pointed out in the U.S. Pat. to LANGTON, No. 3,222,064, the well trained athletes of today vault tremendous heights. Difficulty exists in setting the crossbar at these heights accurately. To set the crossbar manually, requires either the use of hand operated poles to elevate the crossbar to the or 16-foot height or the use of stepladders. This is time consuming, increases the strain upon the performing athlete, and destroys the interest of the spectators. LANGTONs solution is to divide the crossbar in the middle and cantilever the parts from each standard.

CRAIG, U.S. Pat. No. 1,737,108, has suggested that the standard be comprised of telescoping sections and the sections be raised and lowered by a nut upon a hand-rotated screw.

SUMMARY OF THE INVENTION I have solved the problem by mounting the crossbar-supporting pegs for vertical movement upon the standards. Each peg is raised by a halyard and lowered by a downhaul; the halyard passing over a pulley or wheel at the top of the standard. A stop, which is adjustable in height on the standard, is in operative relationship with a protuberance on the halyard so that it stops the movement of the halyard when the peg reaches the desired height.

For automatic operation, I have solved the problem by mounting the crossbar-supporting peg upon a belt or chain which is journaled over a wheel or sprocket at the top and bottom of the standard. The chain is driven by a reversible electric motor. The standard aluminum crossbar is electrically conducted and, therefore, if the crossbar is on the pegs, it will provide an electrically connected path which can be used to energize relay coils to control the motors. When the bar is knocked off, the change of current through the relay coil can be used to energize the motor to lower the pegs to a reasonable height wherein the crossbar may be laid across the pegs. When the crossbar is laid across the pegs, the pegs then again rise to the desired height. The height of the crossbar-supporting pegs is determined by a stop peg on the opposite side of the standard which operates a limit switch upon the standard.

An object of this invention is to set acrossbar for pole vaulting.

Further objects are to achieve the above with a device that is sturdy, compact, durable, lightweight, simple, safe, versatile, reliable and efiicient yet inexpensive and easy to manufacture, transport, setup, operate and maintain.

Still further objects are to achieve the above with a method that is safe, rapid, efiicient, and inexpensive and does not require skilled people to transport, setup, adjust, operate, and maintain.

The. specific nature of the invention. as well as other objects, uses, and advantages thereof, will clearly appear from the following description and from the accompanying drawing, the different views of which are not necessarily to the same scale.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a perspective view of pole vaulting standards and crossbar according to a first automatic embodiment of this invention.

FIG. 2 is a perspective view showing one standard of the first embodiment from the crossbar side, which has been broken and foreshortened for clarity.

FIG. 3 is a perspective view showing one standard of the first embodiment from the approach side, which has been foreshortened and cutaway for clarity.

FIG. 4 is a sectional view showing details of construction of the first embodiment taken substantially on line 4-4 of FIG. 3.

FIG. 5 is a schematic representation of the electrical controls of the first embodiment.

FIG. 6 is a side elevational view according to a second manual embodiment of this invention, which has been broken away and foreshortened for clarity.

FIG. 7 is a sectional view showing details of construction of the second embodiment taken substantially on line 7-7 of FIG. 6.

FIG. 8 is a sectional view showing details of construction of the second embodiment taken substantially on line 88 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing the first embodiment and .referring to the drawing, FIG. 1, it may be seen that a crossbar 10 is supported by pegs 12. One of the crossbar-supporting pegs 12 extends from each of the

standards

14 and 14. The standards themselves are supported upon base 16.

The base 16 has a pair of angle members 18 attached to the upper surface thereof as by welding to form slots.

Foot 20 is attached as by welding as with suitable gussets 22 to the bottom of the standard 14. The edges of the foot 20 fit into the slots formed by the angle members 18 thereby providing a suitable track by which the standard 14 may be moved and adjustably positioned. The reason for this is because that the rules of pole vaulting provide that the crossbar-carrying standards and 14' may be moved closer or further away from the pole trap T.

LANGTON in his U.S. patent, noted above, shows other means for moving the standards back and! forth.

Pillar blocks 24 are at the top and bottom of each of the

standards

14 and 14. (FIGS. 2-4). Shaft 26 is journaled in the lower pillar block of each standard; carrying wheel in the form of a sprocket. This is within the standard 14 which has a hollow rectangular cross section. Also, wheel 30 in the form of a sprocket is joumaled on shaft 28 in pillar blocks 24 at the top of each standard. (FIG. 4). Flexible tension member in the form of endless belt 32 is in the form of a light chain trained around the wheels which are in the form of sprockets. The crossbar-supporting peg I2 is attached to a special link in the belt 32 in the form of a chain. Peg 12 projects through slot 34 on one side of the standard. 0n the backside of the standard, protrusion or height peg 36 is also attached to a special link in the chain 32.

The shaft 26 extends through the pillar block 24 to the outside of the standard 14 and has mounted thereon sprocket 38 which is chain driven from electrical motor 40. (FIG. 2).

High-level limit switch or stop 42 is attached by housing 44. (FIGS. 3 and 4). The housing is held to the standard by bolt 46 which extends through the slot 37 on the backside of the standard through which the peg 36 extends. The housing 44 carries pointer 48 which, in cooperation with indicia 50, indicates the height at which the crossbar-supporting peg I2 is stopped by the limit switch 42.

Limit switch 52 is permanently mounted at some convenient height such as about 5 feet. Operating lever 54 of the limit switch 52 is in the path of movement of the crossbar-supporting pegs 12.

The crossbar 10 is customarily made of aluminum which is electrically conductive. Therefore, when the crossbar is knocked off by an unsuccessful athlete, there will be a change of electrical resistance between the two pegs 12, inasmuch as the belt 32 is conductive. Electrical cable .55 connects the two standards. Measurement of this change of electrical resistance can be used to detect whether or not the crossbar is upon the pegs 12. If the crossbar has been knocked off, the motor 40 is activated to run in a direction which will rotate the shaft 26 in a direction to move the pegs 12 downward. If that part of the belt 32 downward between where it is attached to peg 12 and is trained around the shaft 26 is considered the downhaul and that part of the belt which is above the peg where it is also trained around the shaft 26 is considered the halyard, it may be seen that the action of the motor is to increase the tension on the downhaul so that it is more than the tension on the halyard, thereby lowering the peg. The peg moves downward untilit strikes the reset limit switch 52. At that time the electric motor is automatically stopped by the operation of the reset limit switch.

When the crossbar 10 is again placed across the pegs 12, this change in electrical resistance is used to restart the motors 40 in an opposite direction so that the pegs 12 move upward and continue to do so until the height peg 36 strikes the highlevel limit switch 42 at which time the motor 40 again stops, thus setting the crossbar 10 at the desired height. Again considering the belt 32 to be part halyard and part downhaul, it may be seen that the action of the motor 40 increases the tension on the halyard until it exceeds the tension on the downhaul, thereby causing the peg to be raised. If the athlete successfully vaults the height and it is desired that the bar 10 be raised, all that is necessary is to loosen the bolt 46 and move the housing 44 downward so that the pointer 48 points to the desired height upon the indicia 50. As soon as the housing 44 is moved downward, the high-level limit switch 42 will cause the motor 40 to start again so that the bar will be moved upward to the desired height.

FIG. shows a schematic representation of the electrical controls that accomplish the above operation. In the subsequent description and on FIG. 5, the elements on one standard will be designated as prime for clarity. There is a source of supply of 24 volts, direct current, of electricity such as in the form of battery 56. There is a master power switch 58. Light 60 indicates that the power is turned on by the master switch 50. The battery 56 is connected to each of the standards in series with control relay coil 62 and manual downswitch 64. Manually opening the switch 64 will deenergize the coil 62 as will the removal of the bar 10. Deenergizing the coil 62 will close its contact 66 and open its contact 68 as shown in FIG. 5. Closing contact 66 will energize coil 68 and 70 assuming that the reset limit switches 52 and 52 are closed. Energizing the coil 68 will close motor controlling contacts 72, 74, and 76, for motor 40. Closing the contact 74 will energize the armature 78. The closing of the contact 72 and 76 will energize field winding 80 in a first direction. Likewise the energizing of the coil 70 will close motor control contacts 72', 74, and 76. Therefore, with the case of motor 40', the armature 78' will be energized by the closing of contact 74' and the field winding 80 will be energized in a first direction by the closing of contact 72' and 76. Therefore, the

motors

40 and 40 will rotate in a first direction until the peg 12 reaches the reset limit switch 52 and open same.

When the reset switch 52'is open, the coil 68 will be deenergized and the contacts 72, 74, and 76, will open. The openings of this contact will deenergize the motor 40, stopping the motor 40. Likewise, when peg 12' opens reset limit switch 52', this will deenergize the coil 70 which will open the contacts 72, 74, and 76', which will deenergize the motor 40'. Therefore, the pegs 12 and 12' will remain in the lower position until the crossbar is again placed across the pegs 12 and 12'.

When crossbar is placed upon pegs 12 and 12', the circuit will be completed through the coil 62. The energizing of coil 62 will open contact 66 and close contact 67. (Opposite the position shown in FIG. 5). Inasmuch as limit switches 52 and 52' are already open, the opening of the contact 66 will have no effect. However, the closing of the contact 67 will energize coil 82 through high-level limit switch 42 and coil 84 through high-level limit switch 42'. When the coil 82 is energized, its

contacts 86, 88, and 90, will close. Likewise, the energizing of coil 84 will close its contacts 86, 88', and 90. Closing contact 86 will energize the armature 78 and motor 40. The closing of contacts 88 and 90 will energize the field-winding of motor 40. It will be noted that when the field-winding 80 is energized by closing of contacts 88 and in opposite polarity that it is being energized by the closing of contacts 72 and 76. Likewise, energization of coil 84 will close contacts 86', 88' and 90, which will in like manner cause motor 40 to run in the reverse direction as the motor 40' runs when it is energized by the closing of contacts 72', 74', and 76. Therefore, the motors 40 and 40' will run in a direction causing the pegs 12 and 12' to move upward, carrying with them the crossbar 10. Upon the first movement of pegs l2 and 12, they will move away from the limit switches 52 and 52' allowing them to close. However, inasmuch as contact 66 is open in this position, there will be no energization of the coils 68 and 70.

Then the

pegs

12 and 12 continue to rise until peg 36 opens the high-level limit switch 42 and the peg 36 opens the highlevel limit switch of 42. When these two limit switches are open, the coils 82 and 84 will be deenergiz'ed, therefore causing the contacts to open, thus

deenergizing motors

40 and 40. Therefore, the crossbar will remain in position with the pegs l2 and 12 elevated.

If it is desired to move the crossbar higher, moving the housing 44'so that its pointer 48 moves to a higher numbered indicia 50 will move the switch 42 away from the height peg 36 causing the high-level limit switch 42 to close. The closing of the limit switch 42 will energize the coil 82 which will again start its motor 40 running to raise the peg 12.

If upon an unsuccessful vault, the athlete knocks the crossbar 10 from the pegs 12 and 12', the coil 62 will be deenergized, causing the contact 67 to open, preventing either of the coils 82 and 84 from being energized, but also closing the contact 66 which will energize the coils 68 and 70. This is the condition first described in the explanation of the operation of the electrical circuits.

Describing the second embodiment and referring to the drawing, (FIG. 6), standard 102 is attached to foot 104. The foot is mounted for horizontal adjustment on tracks, however this has not been shown on FIG. 6. The standard 102 has indicia 106 attached to the side thereof.

Standard extension or riser 108 is attached to standard 102 by guide 110 at the top of standard 102 by clamp;112 at the bottom of the riser 108. The clamp 1 12 is bolted to the bottom of the riser 108 and encircles the standard 102. Bolt 114 threaded through the back of clamp 112 bears against the back of the standard 102 so the riser may be clamped in the desired position. Top edge 116 of one side of clamp 112 cooperates with the indicia 106 to indicate the height of the peg l 18 when it is in its raised position.

Track 120 is attached as by welding to the front of riser 108. The track is T-shaped in cross section. Slide 122 rides on the track 120 and moves up and down the track. Peg 118 is attached to the slide. Thus, the peg is mounted for vertical travel on the standard inasmuch as the riser 108 is an extension of the standard and a portion of the standard.

A flexible tension member is attached to the slide 122. The lower portion of the flexible tension member is in the form of a fabric cord called downhaul 124. This end of the flexible tension member is wound around spring-loaded reel 126 mounted at the bottom of the standard 102, specifically, to the foot 104. Spring-loaded reels 126 are commercially available upon the market for clothes line so that the clothes line may be retracted within the cover of the reel when not in use. The purpose of the reel is to prevent the downhaul 124 from becoming tangled as the slide 122 is raised and lowered."

Wheel or pulley 128 is journalcd to the top of the standard specifically to the top of the riser 108. Halyard 130, which is that part of the flexible tension member extending upward from the peg 118, in the form of a flexible steel cable of small diameter, is trained over the wheel 128. Weight 132 is attached to the end of the halyard 130 and is inside the riser 108 which is tubular.

At the bottom of riser 108, detent 134 extends through the wall of the riser. The detent is spring biased inward and may be pulled from the interior of the riser by hand knob 136. By rotating the hand knob, the pins 138 rest upon the shoulder of the barrel 140 so the detent is withdrawn from the riser.

I use the expression that the detent 13 i is on the bottom of the riser 108, although, as seen, it is spaced upward from the extreme bottom. It is on the lower section and for simplicity, the lower section will be referred to as the bottom. Disc cleat M2 is also located on the bottom of riser b.

The crossbar is placed on the pegs 118 and the pegs raised until they are chock-a-block at the top of the standard. Each is raised until the cable connections run over the wheel 128. Alternately, clip 144 may be attached to the track 120 by a setscrew 146. If the clip 144 is used, the slide 122 is run chock-ablock to the clip. The clip 144 is adjusted to set the peg 118 so the edge 116 gives the proper reading upon the indicia 106 for any installation.

To raise the peg 118, all that is necessary is to release the downhaul 124i inasmuch as the weight 132 will overcome the bias of the spring-loaded reel 126 and the weight of the pegs and crossbar thereon. After the peg 118 is chock-a-block at the top, it is desirable to set the detent 131 above the top of the weight 132 to snugly hold it in place and snugly hold the halyard 130 with the peg chock-a-block to prevent accidental movement. In this regard the detent 134 itself could also be considered a stop. Actually, the adjustable stop is the clip 144 (or the wheel 128, whichever is used).

If the athlete vaults the height, the crossbar may be raised by loosening the bolt 1141 and raising the riser 108. Raising the riser 108 in effect adjusts the stop (clip 144) against which the protuberance (slide 122) on the halyard 130 operates.

If the athlete fails to vault the crossbar and knocks it from the pegs 118, each is lowered by manually increasing the tension upon the downhaul 124 to exceed the tension exerted by the weight 132, pulling the peg downward. The downhaul is cleated to disc cleat M2 to hold the peg in the lower position while the crossbar is replaced upon the pegs. After the crossbar is replaced, the downhaul 124 may be released from the cleat 142, again allowing the weight 132 to pull the peg 118 and crossbar upward.

A variation of the above structure is that the end of the downhaul 124 could be attached to the bottom of the weight 132, eliminating the spring-loaded reel 126. Then, if dirt on the track 120 prevented the weight 132 from pulling the slide 122 up, added force could be exerted by pulling downward on the weight. As varied, that portion of the cord from the bottom of the riser 108 to the weight 132 would be a portion of the halyard, 130 which would be used to raise the pegs 118. Also, the peg could be secured chock-a-block by cleating the halyard extension to the cleat M2, thereby also eliminating the detent 13 1.

The embodiments shown and described above are only exemplary. I do not claim to have invented all the parts or elements described. Various modifications can be made in the construction, material, arrangement, and operation, and still be within the scope of my invention. The limits of the invention and the bounds of the patent protection are measured by and defined in the following claims. The restrictive description and drawing of the specific example above do not point out what an infringement of this patent would be, but are to enable the reader to make and use the invention.

SUBJECT MATTER CLAIMED FOR PROTECTION I claim as my invention:

1. In an apparatus for supporting a. a crossbar for pole vaulting having b. two standards each having 0. a crossbar-supporting peg thereon,

d. the improvement comprising in combination with the above:

e. electrical means connected to the standards for detecting if the crossbar is on the pegs, and

f. means connected to the standards for automatically lowering the pegs responsive to the detection that the crossbar is not on the pegs.

2. The invention as defined in claim 1 with the additional limitation of said means for detecting including g. said crossbar made of electricallly conductive material and h. an electrical circuit between the standards which is completed by said crossbar.

3. The invention as defined in claim 2 with the additional limitations of said means for lowering the pegs including j. wheels joumaled in the top and bottom of each standard,

k. an endless belt trained over the wheels of each standard,

and

in. said pegs attached to said belts.

4. The invention as defined in claim 1 with the additional limitation of g. means connected to the standards for raising the pegs to an adjustable position when the crossbar is placed on the pegs.

5. The invention as defined in claim 1 with the additional limitation of said means for lowering the pegs including g. wheels joumaled in the top and bottom of each standard,

h. an endless belt trained over the wheels of each standard,

and

j. said pegs attached to said belts.

6. The invention as defined in claim 5 with the additional limitation of k. a reversible electrical motor drivingly connected to the bottom wheel of each standard.

7. The invention as defined in claim 6 with the additional limitation of m. means for supplying power to the motor responsive to the position of the pegs upon the standards.

8. The invention as defined in claim 6 with the additional limitation of in. means for supplying power to the motor responsive to said means for detecting.

9. The invention as defined in claim 8 with the additional limitation of said means for detecting including n. a crossbar of electrically conductive :material and 0. an electrical circuit between the standards which is completed only by said crossbar.

10. In an apparatus for supporting a. a crossbar for pole vaulting including b. two standards having c. crossbar-supporting pegs thereon,

d. the improved method of setting the crossbar to the desired height comprising:

e. detecting if the crossbar is on the pegs,

f. automatically lowering the pegs responsive to the detection that the crossbar is not on the pegs, and

g. automatically raising the pegs to an adjustable height responsive to the detection that the c. crossbar is on the pegs.

11. The invention as defined in claim 10 with the additional limitation of h. attaching each peg to an endless belt,

j. journaling each belt to one of the standards, and

k. raising and lowering the pegs by moving the endless belts.

12. The invention as defined in claim 10 with the additional limitation of h. measuring the electrical resistance between the pegs to detect if the crossbar is on the pegs.

13. The invention as defined in claim 12 with the additional limitation of j. attaching each peg to an endless belt,

k. journaling each belt to one of the standards, and

m. raising and lowering the pegs by moving the endless belts.

14. In an apparatus for supporting a. a crossbar for pole vaulting including b. two standards, each having c. a crossbar-supporting peg thereon,

d. the improvement comprising in combination with the above:

e. each of said pegs being mounted for vertical travel up and down said standard,

f. a wheel at the top of each of the standards,

g. a flexible tension member extending from the bottom of each standard to and over the wheel,

h. said peg attached to said flexible tension member,

j. a standard extension of each standard called a riser,

k. said wheel at the top of said riser,

111. said riser vertically adjustable,

n. a halyard end of said flexible tension member extending from the peg over said wheel to within said riser,

o. a weight attached to said halyard end of the flexible tension member within said riser, and

p. a downhaul end of said flexible tension member extending down from said peg outside the riser. 15. The invention as defined in claim 14 with the additional limitations of limitations of q. a spring-loaded reel attached to the bottom of said standard, and

r. said downhaul end of said flexible tension member wound around said reel.

Claims

1. In an apparatus for supporting a. a crossbar for pole vaulting having b. two standards each having c. a crossbar-supporting peg thereon, d. the improvement comprising in combination with the above: e. electrical means connected to the standards for detecting if the crossbar is on the pegs, and f. means connected to the standards for automatically lowering the pegs responsive to the detection that the crossbar is not on the pegs.

2. The invention as defined in claim 1 with the additional limitation of said means for detecting including g. said crossbar made of electrically conductive material and h. an electrical circuit between the standards which is completed by said crossbar.

3. The invention as defined in claim 2 with the additional limitations of said means for lowering the pegs including j. wheels journaled in the top and bottom of each standard, k. an endless belt trained over the wheels of each standard, and m. said pegs attached to said belts.

5. The invention as defined in claim 1 with the additional limitation of said means for lowering the pegs including g. wheels journaled in the top and bottom of each standard, h. an endless belt trained over the wheels of each standard, and j. said pegs attached to said belts.

8. The invention as defined in claim 6 with the additional limitation of m. means for supplying power to the motor responsive to said means for detecting.

9. The invention as defined in claim 8 with the additional limitation of said means for detecting including n. a crossbar of electrically conductive material and o. an electrical circuit between the standards which is completed only by said crossbar.

10. In an apparatus for supporting a. a crossbar for pole vaulting including b. two standards having c. crossbar-supporting pegs thereon, d. the improved method of setting the crossbar to the desired height comprising: e. detecting if the crossbar is on the pegs, f. automatically lowering the pegs responsive to the detection that the crossbar is not on the pegs, and g. automatically raising the pegs to an adjustable height responsive to the detection that the c. crossbar is on the pegs.

11. The invention as defined in claim 10 with the additional limitation of h. attaching each peg to an endless belt, j. journaling each belt to one of the standards, and k. raising and lowering the pegs by moving the endless belts.

13. The invention as defined in claim 12 with the additional limitation of j. attaching each peg to an endless belt, k. journaling each belt to one of the standards, and m. raising and lowering the pegs by moving the endless belts.

14. In an apparatus for supporting a. a crossbar for pole vaulting including b. two standards, each having c. a crossbar-supporting peg thereon, d. the improvement comprising in combination with the above: e. each of said pegs being mounted for vertical travel up and down said standard, f. a wheel at the top of each of the standards, g. a flexible tension member extending from the bottom of each standard to and over the wheel, h. said peg attached to said flexible tension member, j. a standard extension of each standard called a riser, k. said wheel at the top of said riser, m. said riser vertically adjustable, n. a halyard end of said flexible tension member extending from the peg over said wheel to within said riser, o. a weight attached to said halyard end of the flexible tension member within said riser, and p. a downhaul end of said flexible tension member extending down from said peg outside the riser.

15. The invention as defined in claim 14 with the additional limitations of q. a detent attached to the bottom of the riser, r. said detent extending into the riser in operative relationship to the top of the weight so that the detent engages the top of the weight and prevents the weight from rising when the detent is engaged.

16. The invention as defined in claim 14 with the additional limitations of q. a spring-loaded reel attached to the bottom of said standard, and r. said downhaul end of said flexible tension member wound around said reel.