JPS5942209A - Device for determining range of operation of double-acting clamping cylinder operating clamping device for machine tool - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for machining a single object when the cylinder is out of its operating stroke. The double-acting tightening to be operated is performed by the opening/closing rod 111, which is connected to the screw 1-on and monitors the operation stroke of the 11th I/1 cylinder. Ii revised and monitored] 1 The fli attachment of a machine tool relates to a device t,'i for determining the operating range of a sliding clamping cylinder that operates a replaceable OH jack of a lathe.

Power 'AT'
The jaw chuck that is used for H1 is usually two
It is operated by a 11 pneumatic cylinder or hydraulic cylinder installed in the f12j rjli. The m4 and tightening devices are connected to each other by a tension rod or a tension tube to the fixed r1q. (・The screw 1-ring of the cylinder performs 4F 61 jili movement,
As a result, the interlocking of I, L & F is carried out in proportion to it. k: 1 (・The end position of all the culms of the 1-piece device must be tightened (= the maximum movement play of the 1-piece device) or 15J The crop is tightened at 3, which is defined by the maximum possible irradiation distance. There is a possibility that the force required for m? This is because the 4) stroke of tightening A, 1, +/I has already been reached. In the li, +'r view performed through +7'>, the light component &i?
As if 7 were to exist and become 1! 1st birthday.

In order to eliminate this safety defect, fWi (instead of the position of the tightening element of the tightening device, the tightening is done by screws 1 - σ)
, 9i is known to monitor. For this purpose, the opening/closing rod connected to the tightening screw 1 of the cylinder is Ai? (・After the IGJ cylinder) It is pulled out to J. This opening/closing rod operates one or more limit switches via an opening/closing cam. This limit switch is set to emit an electric signal 11 immediately before the tightening reaches the terminal position fF+ of the entire stroke of the device, and this signal is uncertain J crop BI? 4. It is also used to display 711 crop processing Rj/J, drive device σ) stop 1 or restraint. As much as possible, stingray 1 mechanical life 1I
III Stopping or restraining the drive device σ) is good, K+7 indicates the entire process of the device to be monitored J9 is O6I・I'
Lf yj position drawing 1:: σ) which takes different sizes depending on i, ? 1-Next technology-C is a replaceable opening/closing switch or a limit switch of +lJO+I. However, the well-known tightening process monitoring device for 'AH') operates the machine tool 1!
I have to do it.

In practice, it often happens that the tightening device ζt Ll has to be replaced with another one, for example the jack has to be replaced with an arm with a longer or shorter total stroke. Contrary to this regulation, IJIJ I#J
Although replacing the cam or tightening it is often neglected to adjust the limit switch according to the 11th stroke of the device i' ((7)), especially on new machines: on f1 machines the cover Since the XI-J cylinder is difficult to access, this operation requires even more care and time.

1) Install the machine tool (11 curved tightening &-1 device and 1) t0° gutter device and set the t0° gutter device to correspond to a specific target stroke. It is also known to do so.

This target stroke is first compared with the actual stroke via an IL comparator. By this comparison, if it is detected that the device r (iB) is out of its movement i γ path, the rbJ east of the I41 machine is carried out. This known device Since it uses a single device, it necessarily has a special configuration and can therefore only be used as a lifting platform on which a machine tool will be installed in the future.Furthermore, this device Due to the difference in lil'i when transmitting , there is a possibility that the position of the movement 11 outside the original movement stroke may also be lost by /1.

The main problem of the present invention is to improve the tightening and tightening devices of the machines II' and I1J of the types mentioned above.
Modify the operating range determining device of the double-acting tightening cylinder to avoid manual replacement of the 1+14 closing cam or adjustment of the limit switch. :
'l' し) converted A? +Fi・1 digit device 1?1 and the electricity required for this −j”A′:ir!J, the device/,
Considering the additional tightening required for the 4U row culm? The solution to this problem according to the present invention is to make the white motion tone f!ri of 1[V, (・1 ? in the operating process of the CT device and \ 11J nt!). Since the 1.te characteristic corresponds to the entire stroke of the tightening device 7, J, it defines the movement of the opening/closing rod caused by the movement maj and ri:: ru by the sensor. The position to which the
When machine movement 11'' is stopped, J) or #η (=I) When replacing the device, additional tightening will maintain the stroke and open 1 to 1j1.
! IJνkuno(+7. ii・'I is automatically erased).

With this configuration according to the invention: I: Operation of the machine tool is stopped! , or after replacing the used tightening device, the necessary and clear J
Taking into account the Li caulking stroke, the position of the opening/closing rod corresponding to the movement stroke can be automatically set. For this reason, each tightening device has a
No associated encoding device is required, and switching of the opening/closing force l\ is also possible.
There is no need to adjust the switch. The setting of the respective end positions of the opening/closing rods is carried out at the start of the actual machining +)il, and is therefore carried out only by the movement stroke.

IQl 141 row culm position that is appropriately adjusted to +3 tIi; in step 1, 1 machine moves i+ 9. '! Will it be II?J
'+Rui kl fat' 1F, when the 1L-J device is replaced, automatic +i! The price is 11, and the price is 7. What is the analogy for electronic devices? :) i; device and i0ri Buddha J.1.k;
Place the place (su! Kawakesu, opening reno, exchange L/ta 0 limit 1
The device according to the invention can easily adjust IF[(
J's] ni 1 machine will take C) take A, I ke C), so
The use of the device of the present invention, which greatly enhances safety, becomes 1iHiH.

In a preferred configuration θf of the device 1', l according to the invention, 11
111! The II rod has 17 open pieces (dj/) with respective open IR+ cams for at least two sensors, each sensor being connected on the other hand by an I11 blank piece respectively. Move to the terminal position +il I'iH, and in other J, the movement of A1 machine is 4'++:j, 3) Or in 1F I'
Eyi Il'l automatically activated when replacing +1 device
With this configuration of the invention, especially when the electric device 1/+ is
According to the present invention, this electronic device i"i can be used even at a position of 1 degree when the JIJ is installed in a machine.
) (frl Ni/I', (i sale f, r i pure mechanical record +4 is 'J01: roar 4, misfire 1111's another note, +f+7!,]; 1
``Nojinku C〕Box guide, ゛7 to keep the inside J, 7 power number JJ
+'(,I) f9, li ill rjl Cobb,!
? 1t WJ good, installed on top, non-¥61111
(This 1-Is each? 1o holiday is open 1' JI piece's opening, and Jl, same I for 1 (-+Jnu fj taken 179 (
jii EL l/1 le C/)-C1A<Yi'i
1lII l-,,h le'k is made up of a small number of parts.

In a preferred configuration of the present invention, the operating screw 1, which is formed by a LIFI cylinder that acts on the reciprocating body, and which operates the screw rod and applies it to the right reversible body, is operated by a Jyjl spring. Mukaihei: This configuration of the Fi5 (') motor is capable of applying pressure to the return spring using the pressure arm and transferring to the non-operating IC'i.
゛Machine tools usually utilize an energy source present in the form of air or pressurized oil.
Operation of the machine 4': In the event of a failure of the CII or the failure of the power supply system, the device according to the present invention is automatically shifted to the zero position, and the permissible operating range is determined. This zero position II1+ restarts the machine tool without any problem.
In another configuration according to the invention, -Ll can be blocked by 11.
Two operating cylinders for use are provided in a support housing facing the vertical guide for the right complex that holds the sensor, and this support housing simultaneously operates an opening/closing cam.
It is configured as the first top part around the guide part If of the III piece. This results in a particularly simple construction, which is further improved according to the invention by guiding the opening/closing cam in an axial recess in the supporting housing sink.

According to the invention, the opening/closing cam extends in the direction of the axis of the knob, and the response of the center is coordinated to suit each memorized end of the opening/closing rod. 7,
As Senhino/! If you use 11 rim 1~swidth 1/12 on KJ, it will reach the mechanical swivel +
) The ego effect opening/closing area of the limit 1 switch which issues an opening pulse to i+/1 maintains the additional tightening stroke. On the contrary, +! 'f j,+D's 4'l''i
．． It can be provided that, when the complex reaches its end position where it is swiveled, the opening and closing pulses that create the movement 4'lIJ culm have already been generated.

In the device according to the present invention, each fit is such that the entire stroke of the device is
tQc, and as a result, the I21rii1 property of Motion I1 is significantly dependent on IshiIJ, so ifl jθ at the time of the 119 constant or setting outside history of Motion I1-1 culm is 41). J) 1 +, : 9 where i is obtained as a rest, and further the 'movement at the end of each tightening A and 1st eye device A'++ 1
For automatic setting of ￥culm, tighten I/Jke over 411:, and? Only one 1/■ operation in the student process is required, and this operation is the tightening of the machine (d3 '7j: In any case, it is done before the start of the 1 machine, so sen 1). The time for setting or setting the gold mine is saved 1. F) L-1 of the opening/closing rod F-1 Clinching setting A; When
By doing 61 people in terms of i diJ, the E1 machine will definitely stop starting at the set movement A1 stroke with an error: -)1, why [-] is the sensor. “ is at the zero position that makes this JI4 combined 4j row culm ′-!?, so +111 The second position of the III bar N=7 is considered to be impossible to close!J, and S1.= 1) To set the range of motion before starting the machining process.
Move! This is because doing 1') will definitely give you peace of mind.

FIG. Ij shows an embodiment of the device according to the invention.

Figures 1 and 2 of the drawings show 1.1 of a 14'1 machine. 1) fj: Thread j on the flI flange of this -7 axis.
? The table “f” where device 2 is removed
(The one-piece device 2 is formed by a claw jack in FIG. 1.

The drawing shows the main body 2a, the main claw, and the plate claw.
Naru 1 phi 1 digit nail 21] is +jjf praised. ,
The chuck screw 1-2c that drives the L-J claw 21) is moved in the axial direction into the ivy body 2a! The OZ1 key transmission device is engaged with the main pawl of the Ll pawl 21+.

Due to the structure of the tightening device Fj 2, in Fig. Sumizu〈),.

When tightening the stingray'1 object between the bucket f and J nails 21), from the l side to the inside ()1 and 1), tighten the -) and ty+ ll1l,'l. It must be 5j/(11, ! Mochikata's release) 1, il should be ν), ノ13 Pa income/rAl
゛11 It is generated 1) II, chuck screw 1 Hen 2 (or its entire process 11 l'lfl !fj
I had to ride Ai or J1L5 11 times. - 1 Crop may be deformed and the teeth of the claw may dig into the 2 I crop. One must always be free from contemplation so that it is still possible. This l! 11
Therefore, the so-called additional tightening is obtained by reducing the stroke N from both sides of the total stroke 11 to 41 strokes.

In order to operate the tightening device 2, a tightening cylinder 3 is attached to the rear flange 1a of the main shaft l, which rotates together with 1141+1, and its screw 1hen'3a connects the piston rod: 31) and the operating outside 4. via Chuck Bis 1 Hen 2
It is combined with C. For this tightening, the cylinder 3 is a double-acting cylinder, for example a hydraulic cylinder, to which Ll and force medium are supplied via a pressure medium transfer housing 5. Pressure medium transfer housing 5 has main i61+I and fastener I
The shaft rotates together with the cylinder 1 and is tightened by a shaft formed with a hole that communicates with the cylinder 3, and this rotating 1lill+-h.
It consists of a static housing 11 supported by a pressure medium housing with a pressure medium connection to a pressure body (not shown).

For tightening, the corresponding position [12I] of the chuck piston 2C and therefore the tightening claw 21 is detected via the respective position of the screw 1-3a in the cylinder 3.

For this purpose, the locking pin X1 is such that the piston 3a of the cylinder 1 is connected to a closing rod 6, which is led out of the locking cylinder 3 through the axis of the pressure medium transfer housing 5. . On the free end of this opening/closing rod 6, an opening/closing piece 8 is supported by a ten-piece I receiver 7 as shown in FIG.
11i is growing. These opening/closing cams 8a and 8b protruding in the 1'-1' radial direction from the opening/closing j18 are guided in the axial notch 9a of the support housing (), so that the opening/closing piece 8 is vertically moved by the opening/closing rod 0. 1 was taken away, but
1 which rotates through its opening/closing cup, 81'I and 81)
It has been ranked 1st. In the illustrated embodiment, the opening/closing rod 6 is
1' A locking bolt attached to the prison Φib I of the machine (1 rotates together with the cylinder 3,
Q7 (I need one for Riko).

What about each opening/closing cam 8a or 8b? i: '6j(
B. The sensor IOa or 101 installed in the eye operates in cooperation with the sensor IOa or 101] installed in the eye. Each of the two reciprocating bodies 11 has a support housing 9
A screw 12 is provided between the head of the screw 13, which is guided by the vertical guide portion 9b of the reciprocating body 11, and a washer 14 formed on the outside of the support housing (). The tightening of is capable of moving against force.

In Fig. 1, the tightening device 2 shown in the form of a knock is attached to the cylinder 3.
As a result, the entire tightening stroke I+ of the device 2 is transmitted to the cylinder 3. In Fig. 1, this tightening means that the lower blade of cylinder 3 has f
+7 (Piston of cylinder 3: 3a (7)
The complete process G that can be performed is entered, and the complete process 11 of the tightening device 2 is written in this complete process (:).

In this movement stroke of the tightening device 2, the rJ complex II holding the sensors 10a and 101) is pressed against the countersunk 12.
is moved to tPl+ by a distance corresponding to the entire stroke 11 against the force of Kn i"J of Kn.
is equipped with a driving piece 11a, and this driving piece +1a is the opening/closing cam 8.
fl on the left of a; In contrast, the sliding body 11 provided at the lower part of the support housing 9 has a driving piece 11b, and this driving piece 111) cooperates with the end face of Yi of the opening/closing cam 81). .

As shown from the left part of FIG.
Through a, Sen → JII) Hold a? -L recovery 1
The body is moved to the left to a position representing the end of the entire stroke 11. Therefore, "l" + <The rightward movement of the piston 3a holds the sensor IOb via the opening IJI cam 8b of the opening piece 8? The i-return vehicle 1 is taken rightward to a point representing the other end of the entire journey 11. The movement process of the uil 4':il device 2 performed in this way is as follows:
Therefore, the corresponding position of the chuck piston 2C, where the opening/closing rod 6 that defines the entire stroke 11 was located, is described as 1! It will get cold.

Two operating motors are provided on the supporting shaft and the hinge 9 in order to shift the retractor 11 from each movement stroke 1) to the zero position defining the total stroke 1).

In the embodiment according to FIG. 3, these actuating motors are each formed by an actuating cylinder 15 which is installed or constructed in the support housing 9. Each operating cylinder 1
5 is provided with an operating piston 15a, and its screw 1-
The rod +5b projects from the housing of the operating cylinder +5 and acts on the corresponding recovery body 11, and its entrainment piece 11h
Or open 1 through llb! The corresponding opening/closing cam 8a or 8b of the A1 piece 8 can be pressed. This pressing is performed by a return spring 15c provided on the inner rx++ of the screw rod 151). This return spring 15c is supported on the one hand by the piston rod 151), and on the other hand is used to close the screw space of the operating cylinder 15. , 715
It is supported by II. For example -I: Machine tool stop I.
Or so that the tightening device 2 can be replaced.
What is the direction of action of the return spring 15c?
When the pressure medium acting on a is cut off, the return spring 15
c acts. In this state, the operating pistons 15a of both operating cylinders 15, which act in opposite directions to each other, are reciprocating bodies of two swords.
Since the sensors IOa and 10b are pressed to the zero position, the sensors IOa and 10b reliably reach the zero (+> position), and fi (sen →] 10a and 101 due to the new movement stroke of the device 2) is
I(1',!) which is not moved to the position defining 1, this zero position +i'i'' causes the start of the machine to 1111.
11. Will be done.

As a result, as mentioned above, the ki+ 4/jke device 20
4'-Both end positions IJ/1 of stroke 11 are shown in 1. In order to ensure a sufficient number of additional tightening strokes N in the range of the final position of the first and second (J) J, the shape flφ shown in FIG. 5 is used. In FIG. 5, the ij'i line drawn on the surface of the sensor I (la 117) %, configured as a non-contact sensor, indicates the rj effect opening/closing area. Similarly, h? ! When the opening/closing part is opened/closed, it is crushed 1 or this (i '8J when it comes to the range of the opening/closing area, →)
Itla's necessity 7J Ill l! II pulse is generated. Therefore, this generation of the opening/closing pulse and the engaging piece 11a
Between the contact of l\ with the opening/closing cam 8a, there is the desired additional tightening f・IL''J line culm N stroke, which is also not entered in FIG. This device is capable of additional tightening of the double-edged blade from the entire stroke 11, and the start of the machine to FiJura only during the operation If culm A (Fig. 1) where N is subtracted by +6. do.

The same effect is obtained by using electro-mechanical limits 1 to switch 16 as shown in FIG. 6 without using the force 1 contact limit 1 to switch 1 as shown in FIG. I can do this 1, this limit 1
- The push rod Hia of the switch 16 also has a top surface in the same way as the opening/closing cam 8 iI.
[1 indicating the initial position taken by +11, contrary to this]
III L/ 7% I (iii is II) J I'l
Move it to the position shown by the actual Xy by l cam 8a ν)1)
When the lever is opened and closed, an opening and closing pulse is generated. 1. What is the opening and closing pulse of the lever? 1 return and 11 days off J111゜1 is 11
11 closed cutlet, generated at 811\hit +iiJ. The conclusion of "shown by the upper dashed line; Shunmaheno f11 () bar 1 fi
+1 moves fj' (-, 1lII IV1k, 8t
When + and 1 middle row piece 11, 1 hit lHH, no G or gate opening pulse will be generated. In this way, as in the non-contact limit switch, even in the air-mechanical limit switch j6, Ju caulking on both sides of the entire stroke 11 can reduce the stroke N to obtain the operating stroke.

Respectively '-1-axis 1 a, 1 digit c-) to be taken: i
(・Move to the entire process 11 of the 1-digit device 2; or the operation process i:jl fi3 center・ItlD and l f+
As mentioned above by 11-), ro3i13shita Z,
#i? 4.1 and 1 cylinder 1 screw 1 screw Ia 51
If the piston '1a is outside the culm A of this note, the mechanical control
The start of the first unit is started by Ifl' I left from step 8” 1. In the case of S, the ray 18 machine will be stopped.
'l+11,j has elapsed, the claw jack shown in FIG. 1 can be replaced with the claw jack shown in FIG. Direction 111IJiiJ Functional tightening τJke screw 1
- I have a 2e. This tightening screw 1-2C
axis X, 1. The movement in the +1 direction performs a tightening movement or a loosening movement of the tightening piece 2, which is tightened between the suppressing pin 2g and the tension screw 211, via the slope seen in FIG.

For the tightening configured as A μ in FIG. There is no lν by one order of magnitude N.

A μ II) J 1. ! By performing the entire movement cycle of 71, the entire iJ' of Aμ is achieved! +'If I is set 4t I fla Oyohi I flb k: set from 3, kil in Figure 2 (・IU cylinder, the entire stroke of 1 (: into the 2nd From the figure, not only is the total stroke of A μ +1'l smaller than the total stroke of the jaw chuck +1, which was attached to Il several times,
It can be seen that the entire stroke of the screws 1-3a is in different ranges.

Therefore, by considering the additional tightening I (1 digit stroke N /'5, IJtl of the total stroke 111 possible for Aμ)
Not only the end position of 11 cup 6 is stored Jd, but also the operation stroke AI is stored M'J. After remembering the value of A μ thus set, when operating the machine tool, the tightening can be such that the piston 321 of cylinder 3 is now only within 1 to the working stroke to be entered by γ1. . Only when screws 1 to 3 +1 are within l to the movement I'+ stroke set to A μ, the four rotation gr of main IV+1111
l is possible. 1 Machine tool stopped 1. Shiteri, -
Go! Both are not 1, and the pressure branch supply device is connected f
〕)〕The main axle load is IIv I, I' L-)
l (Even when exchanging the I-mounting device 2, install /ji: By providing a limiter 1 to a switch 17, the limit switch 17 can be reduced by the VV-like rear surface of the tightening device 2 that can be removed. When device 2 is removed and set to 1, limit 1-swig +7 emits a pulse/l(L, , this pulse is %4
41 Pressure medium 4 to operating screw 15a of cylinder 15
1 fjl, supply inside 14'1 ``Shi, in this way (the return that becomes j effect is t') 15 + nyo-), sen → no 1 +) a and 101) are zero (tk place l\ transition ze) Since both sensors 1fla and 1011 are attenuated at this zero position Wi, there is no operating stroke A or A1, and there is no operating stroke A of the removed tightening device 2.
is determined by the execution of the movement stroke and is realized by the position of the sensor 10a and +(lt+6).
゛11 Earth-moving machinery can be started.

Therefore, the tightening A1j that is taken is only when the operating process A or AI belonging to the device 2 is determined.
1. You can start the dying machine. ! ! ``Monthly M production and J: The production machine and the attached tightening device are removed from the unacceptable operating condition of device r12, +15! (The movement stroke is determined during the song by executing the movement stroke of the fastening device 2 to be released.

[Brief explanation of the drawing]

Figure 1 is a longitudinal side view of the main part of the device rt that determines the operating range of the first cylinder and its one, and Figure 2 is a vertical side view of the main part of the device rt that determines the operating range of the chuck. Figure 3 is a cross-sectional view passing through the axis of the operating range determining device and 1 in Figures 1 and 2; FIG. 4 is a sectional view taken along section line IV--IV in FIG. 3, and FIG. 5 is a sectional view of the device in FIG. 1 to show the additional tightening of the 9iE contact limit switch -F51! Enlarged view of
FIG. 6 is a diagram corresponding to FIG. 5 of a JJJ combination using an electric-mechanical t-limit switch. 1...2] = ill+, 2... tighten (Jke device,:
3...Thread hook/1 piece cylinder, 3a...Tighten with screw 1, 6...1 male rod, JOa + IOb...
・Sensor, A, AI...1IiJI culm,
Il, Ill ... line fI1. N...Additional P
:11 I J Ke process. Run 1-Company:'1Mandy 1-Liselshaf 1-Substitute 1] 11 people Patent attorney 1 Middle I[i Fig, 6 Fig, 5 561

Claims (1)

[Claims] l When the cylinder is out of its operating stroke, the machine tool driving device that processes the workpiece is restrained, and double-acting tightening, which operates the tightening device, is performed when the cylinder is outside its operating stroke. ] The movement of the opening/closing rod that monitors the culm is connected to the piston and the tightening is performed by the movement of the cylinder (2). The entire process (11
Since it corresponds to ゜fth), it is caused by the movement process and the sensor (
10a, IOb), which define the working stroke (A, AI) of the opening/closing rod (6), can be stored for the duration of an uninterrupted machining process, such that -1-' the movement of the machine tool When stopping or tightening the device i': ((
When replacing 2), maintain the stroke (N) for each additional tightening.
A double-acting tightening cylinder operating range determining device for machine tools, characterized in that the position of the +E opening/closing rod (6) 4 is automatically erased. 2 The opening/closing rod (6) has at least two sensors (10a,
Respective opening/closing cams (8a, 81) for IOb l)
Each sensor (IOa, +01)) has an opening/closing piece (8) on the other hand.
) can be moved to the end position that defines the respective operating stroke (Δ.
2) The device according to claim 1, characterized in that the actuating motor (15) acts automatically upon replacement of each sensor (1). 10a, IOb) are movable in the longitudinal guide part (9b) of the support housing sink (C)) against the holding force.1. ;/1 Claim 1st frI or 2nd
Equipment described in Section. The reciprocating body (11) is the opening/closing cam (8a,
8b) and an entraining piece (IL+. 11b) having a cooperative action F3Jnu. Device according to claim 3. 5 The operation motor that acts on the reciprocating body (11) is formed by the operation cylinder (15), and its screw rod (15b)
) The operating piston (+5a), which acts on the reciprocating body (I+)+:
Claim 11, Claim 2, characterized in that a load is applied in the acting direction by c), and the pressure medium is used to resist this return spring (+5c) and shift to the non-actuating amount. equipment. 6 Two operating cylinders (15
) is a reciprocating body (
] 1) A vertical guide part (9b) for (N#) is provided in the support housing (9), and this support housing (9) simultaneously connects the opening/closing piece (8) with the opening/closing cam (8a+8b) αft.
4. The device according to claim 3, wherein the device is configured as a guide portion and a rotating 11th portion. 7 The opening/closing cam (8a, Rb) is the support housing (9)
The device according to claim 2, characterized in that the opening/closing cam (8a+8b) extends in the axial direction and reciprocates. A sensor (10a+]Ob at each end position of the body (11)
2. The device according to claim 2, characterized in that the ;B/Jll tightening stroke (N) is guaranteed by the ability to react in response.