AT510065B1 - BOW TEST STAND FOR A SPORT BOW - Google Patents

Abstract

In an arc test stand (1) for determining at least one characteristic of a sheet (2) having a handle part (3), an upper limb (4), a lower limb (5) and a chord (6), the following devices are provided: Holding device (7) for clamping the sheet (2) for shooting down an arrow (16); Tensioning device (9) for tensioning the sheet (2) on the chord (6) to a default value; Triggering device (10) for triggering the firing of the arrow (16); wherein the holding device (7) for clamping the sheet (2) is formed exclusively on its grip part (3) and, wherein on the holding device (7) a force measuring device (K, 15) is provided, which is used to measure the forces of the grip part (3 ) is formed on the holding device (7) during clamping of the sheet (2) and the shooting of the arrow (16) and, wherein a Wegmessvorrichtung is provided for measuring the of the tensioning device (9) for tensioning the sheet (2) traveled Clamping path is formed, and, wherein an evaluation device (14) by integration of the tension of the sheet (2) measured force on the handle part (3) over the tensioning of the sheet (2) measured tensioning path for determining the potential energy (Epot) in the tensioned arc (2) and, by integrating the force measured at the firing of the arrow (16) on the handle part (3) over the measured at the firing of the arrow (16) tensioning path for determining the in the arrow (16) transmitted kinetic En (Ekin) and, based on the formula (Ekin / Epot) * 100 for determining the energy efficiency of the sheet (2) on the basis of the measured values of only one shot of an arrow (16) is formed.

Description

«Recrase-ts päie;: AT510 065B1 2013-05-15

description

BOW TEST STAND FOR A SPORT BOW

The invention relates to a bow tester for determining at least one characteristic of a sheet having a handle portion, an upper and a lower limb and a chord, said Bogenprüfstand having the following devices: holding device for clamping the sheet for the shooting of an arrow; Tensioning means for tensioning the bow on the string to a default value; Triggering device for triggering the shooting of the arrow.

The document US 2009/0071022 A1 discloses a bow test stand for adjusting and adjusting a bow for shooting arrows. The well-known Bogenprüfstand has a frame in which the sheet is held on the one hand on the handle part and on the other hand on both limbs. In the frame different measuring devices can be installed and also removed again to perform different measurements on the arc in successive firing arrows. A pneumatically driven cylinder forms a tensioning device for tensioning the chord of the sheet. Among other things, the transverse tensile force is measured during tensioning of the arch which is exerted on the tensioning device at the nock point at which the tensioning device pulls on the tendon toward the upper limb and toward the lower limb from the tendon. Based on the result of this measurement, the nock point can be adjusted until the transverse pulling force to the upper limb and to the lower limb is equal, resulting in improved aiming accuracy of the adjusted arch for the shooter.

However, with the known Bogenprüfstand it is not possible to make qualitative statements about the bow to standardize different arches and different types of sheets with each other. However, such a comparison would be necessary to reliably select the appropriate bow or type of bow for the particular archer.

The invention has for its object to provide a bow test, with an objective comparison of different bows and bow types is possible.

According to the invention, this task is solved, the holding device is designed for clamping the sheet exclusively on its handle part and that on the holding device, a force measuring device is provided for measuring the forces of the handle portion on the holding device during clamping of the sheet and the shooting of the Arrow is formed and that a Wegmessvorrichtung is provided, which is designed to measure the distance traveled by the tensioning device for clamping the arc clamping path and that an evaluation device, taking into account the measured tension travel and measured during cocking and shooting the arrow forces to determine a force Path information of the arc and in particular for determining the energy efficiency of the arc on the basis of the measured values of only one shot of an arrow is formed.

As a result, the advantage is obtained that the sheet to be tested is held only on the handle part and, as well as the shooting of an arrow by a shooter, during clamping of the sheet can deform. The force measuring device on the holding device measures exactly the forces that act on the hand or on the arm of the shooter when he tenses the bow and shoots the arrow. By measuring the force profile of the grip part on the holding device during clamping of the sheet and the shooting of the arrow objective characteristics of the sheet can be determined with which sheets can be categorized and certified. Among other things, the energy efficiency or the efficiency of the arc can be determined as characteristic value, which enables an objective statement as to which part of the potential energy present in the arc due to the tensioning of the arc can actually be converted into kinetic energy or airspeed of the arrow. 1/20

It may be mentioned that a measuring method according to Koltze is known in which, in order to calculate the efficiency, a light arrow and an arrow at least five times heavier with the one to be tested Bow must be shot, the velocities of the shot arrows are measured. Based on the different speeds so-called virtual masses are determined and based on this the efficiency of the bow. However, a disadvantage of this measurement method has proven that at least two different arrows must be fired, with the determination of the energy efficiency and the efficiency of the arc with the arc test stand according to the invention is already possible with only one arrow shot.

US 2009/0071022 A1 discloses a machine with which the accuracy of an arc system (especially with a visor) can be increased. It serves the purpose of a Einschießstandes for the calibration of a riflescope as a rifle. The machine is unable to measure the draw weight in the dynamic extension movement. Even when launching no dynamic Zuggewichtsmessung is possible. The machine holds the bow exclusively on the throwing arms. The machine has no central evaluation unit. The pull-out path can always be hydraulic to a maximum. It can not be reached a default value. The energy efficiency can only be very vague over several shots with arrows after "Kolze " are approximately determined.

US 2001/0045211 A1 discloses a damper system for arching arms. The "test rig" described in Figure 8 and described in paragraph 20; is a construction that works purely mechanically and can only be adjusted with the aid of a measuring tape. Even the shot must be solved manually. The tensioning of the bowstring takes place via the tension belt ratchet. The holder for the handle portion of the sheet is not movable.

US 7086298 B1 discloses a device which serves to detect the difference between the force required to tension the sheet and the force that releases the sheet when it is being released. This force is less because the limbs have friction and torsional losses during recovery. The device serves as a model for determining the hysteresis in the behavior of arched arms. This document does not disclose dynamic measurement nor the determination of energy efficiency.

CN 201269764Y discloses a system used in archery training with the shooter. The point here is to bring together the movement errors of the shooter in order to bring the physical constancy to a maximum level (see in particular the last sentence in the English summary).

The US 594041 A discloses a machine with which only compound bows can be measured, with spring carriage are used. With the disclosed machine, no arrow can be fired.

It has proved to be advantageous to measure the clamping path that covers the clamping device during clamping of the sheet. By measuring the forces of the grip part on the holding device and the measurement of the distance traveled during clamping of the arc clamping path of an evaluation unit or by a computer force-displacement information can be displayed as a diagram that is characteristic of the individual arc. Based on this information, a first statement can already be made that a particular archer can use a particular bow very well because of his physical circumstances (for example, arm length, strength, height, ...).

It is also advantageous to measure the airspeed and to use the measured airspeed to verify the basis of the force-displacement information and the clamping path determined energy efficiency of the bow. The higher the energy efficiency of a bow, the better the force used by the archer will be translated into the speed of flight of the dropped arrow.

Since there are right-handers and left-handers among the archers, there are also right-handed and left-handed arches. In a right-handed arc, the arrow rest is at 2/20

austrian piiesSasnt AT510 065B1 2013-05-15 the left side above the handle. For this reason, a right-handed arc of the archer to hang the arrow on the arrow rest and shooting the arrow from the vertical above slightly inclined to the right so that the arrow rests securely on the arrow rest. In a left-hand bend, it is just the opposite. In order to be able to test realistically both right-hand bend and left-hand bend with the bow test stand, it has proved to be advantageous to design the holding device angle-adjustable.

In an arc called the point on the tendon to which the arrow is hung for tensioning, the Nock point. There are bows in which the nock point and the arrow rest are offset in height, which is why it has proved to be advantageous to make the holding device adjustable in height in order to carry out a realistic as possible examination of such sheet can.

Particularly advantageous has proved to provide a computer as a control device of the arc tester, which automatically carries out the entire process of the test procedure - apart from a safety-relevant confirmation of the shooting by the user. Thus, the default value (default clamping force or feed forward travel) and other control parameters are input to the computer, whereupon the checking operation is started. An electromechanical trip gripper grips the bow of the bow and the carriage driven by an electric motor spans vision until the preset value is reached. In this process, the clamping forces are already measured with the force measuring device and after a visual inspection and confirmation by the inspector that no damage is expected at a launch, the release gripper opens controlled by the computer and the firing of the arrow is triggered. The forces that occur when shooting the arrow are measured by the force measuring device and stored together with the determined by the measuring device airspeed of the arrow. The computer then begins the evaluation process and displays, as a result of the test, inter alia the following characteristics of the arc: energy in the extended arc before the arrow is fired (for example, to 28 inches

Tension removed with a force of 55 pounds results in 71 joules of energy); Energy history at launch; · Velocity measurement of the arrow about 20 cm after the separation of the arrow from the tendon; Energy in the fired arrow; · Energy efficiency determined from this; Vibration after firing in the handle.

Further advantageous embodiments of the system according to the invention are explained in more detail below with reference to the figures.

FIG. 3 shows an arc test stand for determining characteristic values of a sheet. [0029] FIG. shows a sheet recordings of the bow test stand according to Figure 1. shows a holding device including sheet recording of the bow test stand according to Figure 1 in an oblique view. shows the holding device according to Figure 3 in a plan view. shows a spindle of the bow test stand according to Figure 1 in an oblique view. shows the spindle of the bow test stand according to Figure 1 in a further oblique view. 3.20

FIG. 7 FIG. 8 AT510 065 B1 2013-05-15 shows diagrams of a Decabow arc determined with the arc test stand when a first arrow is fired. shows diagrams of the Decabow arc determined with the bow test stand when shooting down a second arrow. shows diagrams of the Decabow arc determined with the bow test stand when firing a third arrow.

FIG. 10 shows diagrams of a lance bamboo glass determined using the arc test stand.

Bow when shooting an arrow.

FIG. 11 shows diagrams of a black trophy determined using the bow test stand

Wooden glass bow when shooting down an arrow.

1 shows a bow test stand 1 for determining characteristic values of a sheet 2. The sheet 2 has a handle part 3, an upper limb 4, a lower limb 5 and a chord 6. The bow test stand 1 has a holding device 7, which is shown in more detail in Figures 2 to 4. In Figure 2, a sheet holder 8 of the holding device 7 is shown, in which the handle part 3 of the sheet 2 can be inserted. A locking pin is inserted into the hole of the sheet holder 8 and the chamfers of the sheet receiving 8 allow a tilting movement of the sheet 2 in the sheet receiving 8. In Figure 3, the holding device 7 is shown in an oblique view, in which the sheet receiving 8 is inserted. In Figure 4, the holding device 7 is shown in a plan view. Advantageously, the sheet holder 8 can be removed from the holding device 7 in order to insert another sheet holder, which is specially adapted to the handle portion of another sheet or another type of sheet, into the holding device. As a result, the arc tester 1 for testing different types of sheets is customizable. Another sheet recording could for example have a ball joint to measure only the tensile and compressive forces can.

The bow test stand 1 further has a tensioning device 9, which is designed for tensioning the sheet 2 on the chord 6 to a default value. For this purpose, the clamping device 9 an electromechanically actuable release gripper 10 which engages the chord 6 of the sheet 2 and which is shown in the figure 6. The release gripper 10 is mounted on a carriage 11 of the clamping device 9, which can be moved by a servo motor 12 by means of an internal shaft along a spindle 13 for clamping the sheet 2. A computer 14 controls the entire inspection process of the arc test stand 1 and in this case also the servomotor 12.

Mechanically connected to the holding device 7 is a force measuring device which has a load cell K and a vibration measuring cell 15. The load cell K has Piezomesselemente that measure the pressure of the handle part 3 on the sheet receiving 8. The vibration measuring cell 15 has a sensitive to high-frequency mechanical vibrations sensor, which is formed by a very finely dissolving piezoelectric measuring element and measures the so-called hand shock that an archer feels when firing an arrow 16 on the hand. The forces transmitted by the sheet 2 to the holding device 7 during the testing process are measured by the force measuring device and deliver corresponding measured values to an evaluation device or to the computer 14 of the arc test stand 1. The sheet 2 is clamped in the bow test stand 1 exclusively on its handle part 3 in the holding device 7, which is why all forces during clamping of the sheet 2 and the firing of the arrow 16 act on the force measuring device.

The tensioning device 9 is designed for tensioning the sheet 2 until reaching a predetermined value. The default value can be defined here either as a default clamping path to extract the sheet 2 to, for example, 21 inches clamping. However, the default value may also be defined as a default clamping force in order to bias the sheet 2 until the clamping force of, for example, 40 pounds measured by the force measuring device has been reached. As a result, the advantage is obtained that with the bow tester 1 different test methods are feasible. 4.20

The computer 14 is now formed after the firing of only one arrow 16 with the sheet 2 clamped in the arc test bench 1 for determining a force-path information of the sheet 2. This force-distance information is a characteristic of the sheet 2 and can be used to determine other characteristics of the sheet 2. The determined force-displacement information is displayed by the computer 14 on the screen 17 of the computer 14 and can be printed out. FIGS. 7 to 11 show such force-displacement information determined with the arc test bench 1.

One of the key problems in purchasing a sheet 2 and arrow 16 is to select the appropriate sheet 2 for the individual archer. Each archer has a different span of his arms to stretch the bow. Furthermore, there are stronger or less powerful archers. A variety of different types of sheets are known to those skilled in the art, and a comparison of the different sheet types and sheets can be made on the basis of the force-path information objectively determined with the sheet test bench 1 in order to select the appropriate sheet and arrow for an archer.

In the figures 7 to 11 three diagrams are arranged one above the other, wherein the upper diagram is the force curve measured by the load cell K in the pull-out, or during clamping, of the sheet 2 is shown over the measured tensioning path in inches as Wegmeßinheit , In the middle diagram, the force curve in pounds measured by the load cell K is shown in the launch of the arrow 16 over the path in inches as the distance measuring unit traverses the chord 6 from the tensioned state to the relaxed state. The lower diagram shows the mechanical oscillation measured by the vibration measuring cell 15 or the hand shock when the arrow 16 is fired.

In the following, five determined from the arc tester 1 and printed out with the computer 14 measurement records of measurements are given, the diagrams are shown in Figures 7 to 11.

In the first measurement, a Decabow bow was used and a first arrow with a weight of 388.9 Grain inserted. The Grain unit is a long standing unit of weight with the Grain to Gram conversion factor given as follows: 1 gram equals 15.4326 Grain. The first arrow weighs 25.21 grams. The trigger gripper 10 grips the chord 6 and the carriage 11 pulls the chord 6 by a 21 inch (= 28 inch extension minus the stand height or the removal of the unstressed arc from the handle to the 6.71 inch Nock point). Here, the force measuring cells 14 measures the force curve shown in the upper diagram FIG. At the computer 14, the user is asked if the firing of the arrow 16 can be initiated. The user makes a visual check that no damage is to be expected at a launch, and confirms this by pressing a button on the computer 14, whereupon the trigger gripper is opened by the computer 14 and the arrow 16 is fired. During the launching of the force measuring cell K, the force curve is recorded in the middle diagram of FIG. 7, and the handshock in the lower diagram of FIG. 7 is measured by the vibration measuring cell 15.

BOWDYNO Boaenor test bench - Measurement protocol 3ogen- and measurement data name Decabow4009003 Pfeil 01 Customer ID 2010DB001 Bow designation Decabow 4009003 Bow type Longbow Bow strength 45.000000 Name Mustermann 5/20

AT510 065B1 2013-05-15 feirreiösise-ts pifSSSäiSt

First name Max Street Street 1 Postcode 8212 Town Pischelsdorf Country Austria Email: Mustermann@muster.cc Checkpoint 29.05.2009 15: 58: 34,046

Arrow Shooting Measurement Arrow nummer Weight [gr] Spine [-] Arrow w. [f / s] Pulling force [Ibs] Stand height [inch] Extract [inch] 1 1 388,90 49,00 188,44 41,96 6,71 28,00

3feif-Bogen efficiency according to BOWDYNO

Arrow Mass [gr] Accelerated Total Mass [gr] Loss Mass [gr] Arrow v [f / s] Energy Arrow [J] Energy Arc [J] Efficiency [%] 389.00 686.83 297.83 188.44 41, 51 51,14 81,18 The computer 14 is now formed on the basis of the force-displacement information when extracting the arc 2 for calculating the potential energy Epot in the strained arc in Joule. For this purpose, the area under the determined curve in the upper diagram in FIG. 7 is calculated by integration, which in this case has resulted in 51.14 joules. The computer 14 is further formed on the basis of the force-displacement information in the course of the force launch of the arc 2 for calculating the transmitted in the arrow 16 kinetic energy Ekin in Joule. For this purpose, the area under the determined curve in the middle diagram in FIG. 7 is calculated by integration, which in this case has yielded 41.51 joules. From this, the computer 14 calculates the energy efficiency or the efficiency of the arc as efficiency = (Ekin / Epot) / 100 [%]. In this first measurement, an energy efficiency or an efficiency of 81.18% was thus determined.

As a result, an objective testing and calculation method is obtained to compare different sheets with each other.

The sheet measuring station 1 now also has a measuring device 18 for measuring the flying speed of the arrow 16. The measuring device 18 is formed by two conventional photointerrupters, which are provided at a certain distance from each other. Based on the time difference of the signals of the two light barriers can thus be concluded that the arrow speed. In the first measurement, the computer 14 measured an arrow speed of 188.44 feet / second. 6.20

The computer 14 is now designed to check the theoretically determined energy efficiency of the sheet taking into account the measured arrow speed and the arrow weight. The following formulas are used for this:

Observations:

Final velocity of the arrow (arrow v) [f / s]: vEnd arrow mass [gr]: mPfeil

Force progression at launch force at time t [Ibs]: F (t)

Force curve when extracting via extraction path [Ibs]: F (s)

Extraction path [inch]: sEnd firing duration [s]: tEnd

Calculated values:

Potential energy of the arc [J]: EpotBogen Kinetic energy of the arrow [J]: EkinPfeil Accelerated total mass [gr]: mTot Loss mass [gr]: mVer Efficiency [%]

Ekin Arrow = m Arrow / 2 * vEnd ** 2 mTot = 1 / vEnd * int (F (t) * dt, 0, tEnd) mVer = mTot - mPfeil

EpotBogen = int (F (s) * ds, 0, sEnd)

Efficiency = (Ekin arrow / EpotBogen) * 100 This has the advantage that the computer 14 is designed to check the theoretically determined energy efficiency of the tested sheet 2.

In the second measurement again the Decabow sheet was used, but a second arrow with a weight of 410.51 grains (= 26.64 grams) inserted. As can be seen on the basis of the diagrams of the measurement results shown in FIG. 8 and in the subsequent measurement protocol, a completely different force curve results during firing.

BOWDYNO Boqenprüfstand - Measuring log 3ogen- und Messungsdaten name Decabow4009003_Pfeil_02 KundenJD 2010DB001 Bow type Decabow 4009003 Bow type Longbow Bow strength 45.000000 Name Mustermann First name Max Street Street 1 Postal code 8212 Town Pischelsdorf Country Austria Email MustermannPmuster.cc Checkpoint 29.05.2009 16: 03: 38,062 7.20

Mercerefcisdits AT510 065B1 2013-05-15

Arrow Cuttings Measurement Arrow nummer Weight m Spine Η Arrow Weight [f / s] Extraction Force [Ibs] Stand Height [inch] Extract [inch] 1 1 410,51 62,00 188,44 41,73 6,53 28 00

Arrow - arc efficiency after BOWDYN O arrow mass [gr] Total mass accelerated [qrl loss mass [gr] arrow v [f / s] energy arrow [J] energy arc [J] efficiency [%] 411.00 672.19 261 In this second measurement, a very high efficiency of 87.49% was thus determined, from which it can be seen that the Decabow arc interacts very efficiently with the second arrow.

In the third measurement again the Decabow sheet was used, but a third arrow weighing 432.11 grams (28.06 grams) was placed. As can be seen on the basis of the diagrams of the measurement results shown in FIG. 9 and in the subsequent measurement protocol, a similar force curve results at launch as in the second measurement.

BOWDYNO Boom Test Bench - Measurement Protocol

Sheet and measurement data name Decabow4009003_Pfeil_03 Customer ID 2010DB001 Bow type Decabow 4009003 Bow type Longbow Bow strength 45.000000 Name Mustermann First name Max Street Street 1 Postal code 8212 Town Pischelsdorf Country Austria Email: Mustermann@muster.cc Checkpoint 29.05.2009 16: 05: 32,718 8/20

AT510 065B1 2013-05-15

Merreöiise-ts piiesSasnt

Arrow Shooting Measurement Arrow nummer Weight F9l Spine [-] Arrow w. [f / s] Pulling force [lbs] Standard height [inchl Extract [inch] 1 1 432,11 75,00 185,49 41,70 6,52 28,00

Arrow - arc efficiency after BOWDYN 0 arrow mass [gr] Total mass accelerated [gr] loss mass [grl arrow v [f / s] energy arrow [J] energy arc [J] efficiency [%] 432,00 683,48 251 , 48 185.49 44.67 50.25 88.90 In this third measurement, a very high efficiency of 88.90% was likewise determined, from which it can be seen that the Decabow arc also interacts very efficiently with the third arrow ,

In the fourth measurement, a lance bamboo sheet was used and the second arrow weighing 410.51 grains (26.64 grams) was placed. As can be seen from the diagrams of the measurement results shown in FIG. 10 and in the subsequent measurement protocol, a completely different force curve results than in the previous measurements. It is noteworthy that the handshake of this arc, although low average amplitudes, but that three characteristic high amplitudes occur separately from each other in time. An archer feels these amplitudes as three relatively hard blows in the hand, which is why this bow has an unpleasant hand shock.

BOWDYNO Boqenprüfstand - Measurement report 3ogen- and measurement data name LanzBambusglas Pfeil_01 CustomerJD 2010DB001 sheet name Lanz bamboo glass arch type longbow sheet strength 40.000000 Name Mustermann First name Max Street Street 1 Postcode 8212 City Pischelsdorf Country Austria Email: Mustermann@muster.cc Date of review 29.05.2009 16: 18: 15,406 9/20 asterreidBsd! «Pitwiarot AT510 065 B1 2013-05-15

arrow kills

Measurement arrow number Weight Spine Η arrowqw. Pulling force [Ibs] Stand height [inchl Extract [inch] 1 1 410,51 62,00 175,31 40,33 6,26 28,03

Arrow - Arc Efficiency nac h BOWDYN 0 Arrow Mass farl Accelerated mass farl Loss mass [gr] Arrow v [f / s] Energy Arrow [J] Energy arc [J] Efficiency [%] 411,00 708,89 297,89 175 In this fourth measurement, a rather low efficiency of 80.73% was determined, from which it can be seen that the decabow sheet interacts better with the second arrow in the second measurement than that Lanz bamboo glass sheets.

In the fifth measurement, a Black Tropy wood glass sheet was used and the second arrow weighing 410.51 grains (26.64 grams) was placed. As can be seen from the diagrams of the measurement results shown in FIG. 11 and in the subsequent measurement protocol, there is again a completely different force curve during firing.

BOWDYNO Boaenor Test Bench - Measurement Protocol

Sheet and Measurements Name BlackTrophy Pfeil 01 Kundenl D 2010DB001 Sheet Name Black Trophy Holzglas Bogenart Longbow Bogenstaerke 45.000000 Name Mustermann First Name Max Street Street 1 Postal Code 8212 Town Pischelsdorf Country Austria Email: Mustermann@muster.cc Checkpoint 29.05.2009 16: 27: 01,484 10 / 20

&& »id> AT510 065B1 2013-05-15

Arrow Shooting Measurement Arrow nummer Weight [grl Spine [-] Arrow w. [f / s] Pulling force [Ibs] Stand height [inch] Extract [inch] 1 1 410,51 62,00 185,16 53,77 6,03 28,00

Arrow Arc Efficiency nac η BOWDYN O Arrow Mass [gr] Total Accelerated Mass [gr] Loss Mass [gr] Arrow v [f / s] Energy Arrow [J] Energy Arc [J] Efficiency [%] 411.00 1319.82 906.82 185.16 42.35 63.62 66.56 In this fifth measurement, a very low efficiency of only 66.56% was found, from which it can be seen that the Black Tropy wood-glass sheet does not fit well with the second arrow interacts.

Furthermore, it follows from the five measurements that different arrow speeds were achieved with the arcs depending on the arrow used, although for each of the five measurements was given as a default value of the default clamping distance of 21 inches.

With a separate device - a so-called spin tester - a so-called spine of the three arrows is determined. Spine is the rigidity of an arrow. A too soft arrow is bent too much and sways too long, so does not stabilize fast enough, or it even drifts to the left in flight (in a right-handed shooter), because he has to bend around the bow when shooting. One speaks also of the so-called Bow paradox. The first arrow is light and also soft or slightly bendable. The second arrow is classified as medium heavy and medium hard and the third arrow is relatively heavy and hard. The hardness of an arrow, however, depends on different influencing factors (for example, material of the arrow). The joint assessment of the measurement results of the bow test bench 1 and the spine of the arrows used allows an overall evaluation of the bow-arrow system to select the optimum system for the particular archer.

It may be mentioned that the following conversion factors apply to the units indicated in the measurement protocols on ISO units: 1 lbs = 0.453592 kg; 1 m = 3.283 feet; 1 m / s = 3.283 f / s. 11/20

Claims (8)

Test bench (1) for determining at least one characteristic value of a sheet (2), the one handle part (3), an upper limb (4), a lower limb (5) and a chord (6), said arc test stand (1) comprising the following devices: holding device (7) for clamping the sheet (2) for firing an arrow (16); Tensioning device (9) for tensioning the sheet (2) on the chord (6) to a default value; Tripping device (10) for triggering the firing of the arrow (16), characterized in that the holding device (7) for clamping the sheet (2) exclusively on its handle part (3) is formed and that on the holding device (7) has a force measuring device (K, 15) is provided, which is designed to measure the forces of the handle part (3) on the holding device (7) during clamping of the sheet (2) and the shooting of the arrow (16) and that a Wegmessvorrichtung is provided, the for measuring the clamping travel traveled by the tensioning device (9) for tensioning the sheet (2), and in that an evaluation device (14) integrates the force measured on the gripping part (3) during clamping of the sheet (2) during clamping of the arc (2) measured tension path for determining the potential energy (Epot) in the tensioned arc (2) and, by integration of the firing of the arrow (16) on the handle part (3) measured force over the firing of the arrow s (16) measured to determine the transmitted in the arrow (16) kinetic energy (Ekin) and, using the formula (Ekin / Epot) * 100 to determine the energy efficiency of the sheet (2) on the basis of the readings of only one arrow (16) is formed. 2. Bogenprüfstand (1) according to claim 1, characterized in that a measuring device (18) for measuring the flying speed of the arrow (16) is provided and that the evaluation device (14) based on the measured airspeed (vEnd) for determining the actual kinetic Energy (Ekin arrow) in the shot-down arrow (16) using the formula Ekin arrow = m arrow / 2 * vEnd ** 2 and to check by the evaluation (14) based on the measured values when tensioning the sheet (2) and the arrow (16 ) determined energy efficiency is formed. 3. bow test stand (1) according to one of the preceding claims, characterized in that the holding device (7) is angularly adjustable to adjust the clamped sheet (2) from the vertical into a right and a left inclined position, in particular hydraulically. 4. bow test stand (1) according to one of the preceding claims, characterized in that the clamping device (9) at the nock point of the chord (6), for tensioning the tendon (6) engages, and in that the holding device (7) formed height adjustable is to take into account a height difference of the grip part (3) and the nock point of the arc (2). 5. bow test stand (1) according to one of the preceding claims, characterized in that the clamping device (9) has an electromechanically actuable release gripper (10), which releases the tensioned tendon (6) for triggering the firing of the arrow (16). 6. Bogenprüfstand (1) according to one of the preceding claims, characterized in that the clamping device (9) on an electromechanically driven carriage (11) is provided, and that a control device (14) for tensioning the sheet (2) the carriage (11 ) depending on the default value until reaching a default clamping force or until reaching a default clamping path moves. 7. bow test stand (1) according to one of the preceding claims, characterized in that the holding device (7) in the holding device (7) and retractable from the holding device (7) removable sheet receiving (8), with the bow tester for testing different Bow types is customizable. 12/20 Austrian! föreütawt AT510 065B1 2013-05-15 8. A method for determining at least one characteristic value of a sheet (2) on a sheet tester (1), wherein the following method steps are performed: clamping the sheet (2) for firing an arrow (16) in a holding device (7); Tensioning the sheet (2) at the chord (6) to a default value; Triggering the firing of the arrow (16); characterized in that the forces of the grip part (3) on the holding device (7) during clamping of the sheet (2) and the shooting of the arrow (16) are measured and that of the tensioning device (9) for tensioning the sheet (2 ) and that, by integrating the force measured on the gripping part (3) during clamping of the sheet (2) over the tensioning path measured during clamping of the sheet (2), the potential energy (Epot) in the tensioned sheet (2) is determined and that, by integrating the force measured at the firing of the arrow (16) on the handle part (3), the kinetic energy (Ekin) transmitted into the arrow (16) is determined via the tension path measured when the arrow (16) fires using the formula (Ekin / Epot) * 100 the energy efficiency of the sheet (2) is determined on the basis of the measured values of only one shot of an arrow (16). For this 7 sheets drawings 13/20