DE7131567U - Torque-dependent air shut-off control valve for pneumatically operated tools - Google Patents

Description

Dr. Hans-Heinridi Willrath ' Dr. Dieter Weber

PATENT LAWYERS

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Ohloago Pneumatio (Cool Company, Kew York, N. Y. (USA)

Torque-dependent air oHeßebeuBTTentil IUp pneumatically operated tools

Priority »of August 19, 1970 in USA, Ser. Uo. 65 059

i 'The invention relates to Drehmbmenteneteuer- ▼ orriehtungen for the air closure for pneumatically operated tools such. B. screwdrivers and the like Drive of threaded fasteners, z. B. Very screws or nuts can be used. The general purpose of the performance is to keep the operating air flow to complete the motor automatically when a predetermined amount of torque has been applied to the workpiece.

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Control devices of this general type are known from U.S. Patents 2,952,176 and 3,373,824, after which the device in the tool body between the throttle valve and the engine. These known devices are not completely separated from the housing separately arranged elements of the tool. Due to their construction, they cannot be removed from the housing or built into it as a single unit, but must be placed within it piece by piece. It is also necessary that parts of the housing must be removed to accommodate their parts. Further is the device according to the ySA patent register 3 373 824 of complex structure, dsl * obviously * eger »their big-8s Sensitivity is required. The known devices have neither the advantageous construction nor features of the present invention.

<An advantage with the invention is that ■%) ■ a fully-side unit or can \ separated from the tool is present, and defl the fully-side unit can be adapted as such or to the tool to be removed therefrom.

Another advantage of the invention resides in that

. ■ j.- 'Construction of the valve element, which is so designed, tV ^; > that it is balanced pneumatically over its circumference by the use of 'S I:.: -. "' ^ - of circumferential canals, whereby it is in the

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Is able to work with minimal friction. This feature also serves as a means of collecting residual oil

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Lubricant for the valve.

Another feature is the design of the piston and rod of the valve, which is why there is no complex precision

Manufacture of multiple opening solutions are required.

,. "Bin ..welt.e.rftr.JüqrteJLl is duroh a leadership body given that does not only guide the valve in his Movement serves, but also as a compensatory posture for

aas valve is used. In addition, the nioser body serves to seal the piston chamber against undesired air leakage

Another feature is the use of a Screw and traveling nut combination for adjustments to the spring load. The threaded area the screw is always completely contained inside the unit and protected against dust and dirt.

Under no circumstances can the traveling nut work independently of its set position. This comes from * r Assignment for adjusting the screw and traveling nut of a Sleeve lock her, as well as a Retaining Versohließkappe for the thread engagement with the sleeve lock

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linear load through the traveling nut and the Advantages, Features and Applications ^ gliohkei- Pig. 1 a cross-sonality view through a pneuma • »· · * ·· ···· ·
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- 4 -. . ; oonraüDö ctüx uic üa ^ pö roiauiv 2Ui- Hulsensperrs from. ; gBnden'Erfinduiig er ^ i} ih ^: siok from the consequences table driven rotary screw gun, Ness. With this arrangement, the load is exerted by the valve spring Further . -. the description in connection with the drawings. It in which the LuftversohlisSsteusrventil as a constant :;: ,, .. · ■,. ".., ...., / ■, fl * tn-dejr _Sl ? Rprliip point '■. · ■. · ( is shown fitted in a bore, the extends across the housing of the tool} j only so much of the tool is shown • I. as necessary to illustrate the arrangement is, , -V Pig. 2 a section through the valve unit the line 2-2 of the Pig. 1, Jig. 3 a detail in vertical section of the. Case lock,. . . Pig. 4th a detail in vertical section through the valve, Pig. 5 a bottom view of the valves and Pig. 6th a side view of the stiffener hood and . i 1. · T'i; * * -.- ^. -run nut. * -.,. ■ · - ^ Γ ■ _ '·'
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Xn the figures is an air powered tool, · »B, a rotary-ear cleaner 8, shown in which an air shut-off control valve 9 is included; only so much of the rotary-ear magic tool is shown as there is clear understanding for it the invention is required. The tool has a housing 10 in which a manually operable throttle valve 11 for regulating the flow of compressed air to an air-driven motor 12 of the tool is enclosed. Of the The motor is of the normal type with radially slidable sole stickers in the rotor. The valve 9 is in the housing in.Wege des Air flows fitted between the throttle valve and the engine. During the operation of the tool when turning down a nut • the valve speaks to a predetermined

_{Te torque load} on the engine a $ to complete the flow of the ar tbaiteluft from the throttle valve to the engine.

.. The valve 9 is in the form of a can or capsule.

_. > Be has a tubular jacket 13 which is attached to a End by means of a single-section wall and is provided with a cap 15 at its other end. All components of the unit are contained in the box *. An externally threaded locking sleeve 16 couples the Cap to coat. The sleeve is partly in the mantle

. . robbed in; furthermore, part of it jumps out ^: 'in front of the coat over which the cap is dusted.

The jacket has a side inlet opening 17, with the

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the throttle valve is connected via a housing pipe 18 *. A suction seat 19t, which forms an outlet opening through a side surface of the dumbbell, connects via a housing passage 21 with the motor chamber.The jacket provides a cylindrical inner chamber 22 in which a control piston valve 23 can be moved axially into an open position, a closed position with respect to the outlet 19 is ruined .

The piston valve is axially at one end of a column

benstabes 24 attached. The valve has a support relationship to the wall of the piston chamber. The lower (dell of the piston rod hangs down slidably at any time in a bore extending axially through a valve guide or guide body 26. The guide has a similar part 27 of larger diameter, of which axially a smaller plunger The circumference of the beoher-like part has a support or bearing relationship to the wall of the piston chamber · The holder acting through the wall of the piston chamber on the valve 23 and on the valve guide 26 together with the holder provided by the guide to the piston rod 24- keeps the axis of the valve in coincident relation to the axis of the piston chamber at all times.As a result of this advantageous construction, the valve is resistant to vibration or lateral counter-movement relative to the piston chamber, and as a result it is suitable to move in the latter with minimal friction.

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The piston valve is by means of a spring 28 against one end of the basket chamber 22, as in Pig. 1 is shown biased. In this normal position the valve is both from the outlet 19 as well as from the inlet 17 spatially free. In this state of the valve, the flows out of the inlet 17 working air entering the piston chamber through outlet 19 for driving the motor. The pen sits as shown in Figs. 1 and 4, at one end in an annular recess 29 of the valve? on his other The end of it sits on an inner shoulder 31 of the valve guide. An O-ring seal 32 in the valve guide diohttc against air leakage around the guide of the piston chamber away.

Means are provided for adjusting the load on spring 28 on the piston valve. This facility has the valve guide 26, the shoulder of which rests against one end of the spring, and its plunger at all times is held in contact with the traveling nut 33 under spring load. An adjustable screw 34 is in the nut screwed in and protrudes axially at its inner end into the bore of the valve guide. The outer end of the The screw is formed with a head 35 which has a flange part 36 arranged within the locking sleeve 16, which rests on a bent-in ring flange 37 of the cap 15 under the spring load. The head of the screw is with circumferential play in an end opening 38 of the cap.

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orderly. A sole 40 in the head of the screw protrudes through it the opening in the cap * allows easy access to a Screwdriver or screwdriver is enabled for this. A circumferential play around the paddling part 36 of the screw head is provided by means of an inner groove 39 in the locking sleeve, whereby it is possible that the Planschteil sioh with the screw relative to the locking sleeve turns. Di® locking sleeve has an inner polychrome & surface 4-1 (here hexagonal shape), in which there is a complementary circumferential surface of the socket 33 in an axially slidable manner Relationship strikes. Due to the above mentioned Construction, the locking sleeve 16 is used to guide the nut 33 for relatively axial run and holds the nut against relative rotation when screw 34 is rotated in one direction or another.

You can see that in Pig. 1 rotating the Sohraube in counterclockwise direction neon application of a The nut 33 and slotted end of the screwdriver causes guide 26 to slide upward against the spring to increase the spring load on valve 23. Turning the screw in Uhiizeigerrichtung is used Relief of the spring on the valve.

... 'The pit 34 has a further function in that its inner end serves as a bracket which, with the rod 24 of the valve 23, serves to limit an excessive

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Axial movement of the valve from its normal position continues to cooperate. The excess of this movement ranks off "to allow the valve" to close the outlet port 19 So keep and the flow of working air there, in hindu too But the movement is not sufficient to close the inlet opening 17, so that inlet air continues to enter the piston chamber after the outlet port is closed.

The piston valve 23 is provided with a restricted Dorohgang 43, which is connected to the piston chamber area as the inner 2nd © of the valve through the valve with slight play 44 at the rear end of the valve. This game is a narrow, somewhat protruding dumbbell by the stop with the \ Bndwand dee dumbbell

End of the piston rod created. Into the piston chamber -> from the BInIaBSffnung 17 working air entering flows ■ '' -: usually free and with essentially the same Vo- ■} '■ lumen through the Auslaööffnung 19 "since the latter in the wee local same square measure has; it flows out through the enclosed passage 43 in the valve for filling the clearance 44.

<The surface of the rear end of the piston valve ^ next to the clearance 44 is greater than that of its interior due to the spring load acting on the valve

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and the free movement of the inlet air through the outlet does not normally develop enough air pressure in the free space or clearance to achieve the "idaretand of the ■ 'to overcome spring load. If, however, due to the

development of a predetermined torque load on the engine> - z. B. when the work is done - back pressure develops in the free space 44 and is sufficient; Measures to overcome the resistance of the spring load- () ■■. '; the, the back pressure pushes the valve 23 naoh down, so; that the outlet 19 is closed. Here the [ -. Air flow to the engine blooklertj but the intake air flows. continue as long as the throttle valve 11 is open.

through the unsealed inlet 17 into the piston chamber ; , · And through the restricted passage 43 into the empty space 44, where the valve 23 is in the closed position

holds. When the throttle valve is released to the closed position r 1, the spring returns the spool valve 23 In '_ <to its open position as the air from the free _t ' ^J 'space 44 flows into the outlet 19 for ventilation by the engine.

"■ '■' \ The piston valve 23 is formed with a plurality of channels 45, each of which extends all around its circumference, spaced parallel to the others. The channels so have a desirable advantage. they allow the movement of the valve with minimal friction. In this regard, the amount flowing out around the valve fills the channels

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Incoming air as soon as possible and completely through these channels. The pressure the inlet air within the ducts, which acts on the valve, is evenly distributed so that the valve is pneumatic with respect to the air pressure acting around its circumference. is balanced. As a result, the valve can move within the piston chamber with a minimum of friction or move with a lower degree of friction than would otherwise be the case, where the channels would not exist and the air pressure could develop on the edge around the side area of the valve.

The channels 45 create yet another advantage in that they serve to collect a certain part of the oil mist normally contained in the working air. This result is used to promote the lubricant and another slight movement of the piston valve.

The spring load 28 on the piston valve is determined the value of the torque load required to develop on the engine at which the spool valve 23 is caused to be in the closed position to move; and it determines the degree of torque applying ring on the workpiece. This torque value can, if desired, by optionally setting the Sohraube 34 can be varied.

As mentioned above, the Luftabechaltsteuervorrioh-

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device 9 a complete unit or can. All of its components are provided within its shell 13 and are held in it by means of the cap 15. The unit has a cylindrical shape with a uniform outer durometer over the entire length and fits into one with open ended bore 4-6 looking across the general housing 10 of the tool extends. Duroh Druok, the can is fitted into the hole so that it can it holds its appropriate position (snug fit or shrink fit). The cap part 15 is as in Pig. 1 shown 1st, formed so that it protrudes from the adjacent surface of the housing of the tool. Here you go sioh results in a particular advantage in that not only a screwdriver has access to the slotted head ! . the adjustment screw 35 is enabled} but it is j - this also makes it possible to easily remove the cap from the dumbbell for repairs and replacement of internal parts or components of the unit. When the cap is removed, the adjusting screw can be "" removed together with the The nut 33 is easily removed for inspection will. To remove the remaining components or items, you only need the sleeve lock 16 with the help of a key, e.g. B. a hexagon wrench to unscrew. The remaining individual parts can then can be removed from the jacket by falling out or by sliding it gently out of the jacket. Since the Yorriohtung 9 is located completely outside the tool

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not · unity, it can still easily be printed out in its entirety and, if necessary, replaced by a new one.

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j 1

Claims (4)

Please check 1. Pressure dependent air shutoff control valve inserted into the Body of a tool in an airflow passage two an air supply inlet and an air motor is attachable. with a tubular jacket with an inlet port and an outlet port at different Levels, with a piston valve in the jacket against a spring force in the closed position the outlet opening is movable against air pressure at the outlet opening, whereby by a restricted Durohgang in the "valve pressure development over the head of the valve in a sufficient way the opposite Overcomes spring force, characterized in that the jacket (13) closed at one end (14) auoh at an opposite open end is closable by means of a removable cap (15), the cap forms with the jacket a can containing all valve components (23 »24, 26, 33, 34) which can be removed in the body (10) of the tool for mating the inlet opening (17) with the air supply inlet (18) and the outlet opening (19) can be entered with a Durohgang (21) leading to the motor (12). 2. Valve according to claim 1, characterized by a slidable guide (26) in the can (13, 15) under inclusion - 15 - 713156725.11.71 w * f t • · t- c - 15 - a hanging rod (24) of the valve (23), wherein the guide is axially adjustable with respect to the spring (28) to vary its load on the valve. 3. Tentil naoh claim 2, characterized in that dafi a traveling nut (33) in the pose (13, 15) at one end the guide (26) and axially with respect to the guide by means of an adjusting screw (33) in the box is movable, and that the incense mediate an In an 'end opening (3d) of the can inputtable Drehaohraubers can be actuated. 4. Valve according to claim 1, characterized in that the piston valve (23) is provided with several parallel channels (4-5) which extend around its circumference and which flow out of the valve chamber (22) air fillable fcind. 713156725.11.71