DE1477447A1 - Pressurized tool - Google Patents

Description

PATENT LAWYERS

PATENTANWÄLTE LICHT, HANSMANN. HERRMANN • MÖNCHEN 2 · THERESIENSTRASSE 33

(J 25 841 Ib / 49a)

Ingersoll-Rand Company

Dipl.-Ing. MARTIN LICHT Dr. REINHOLD SCHMIDT Dipl.-Wirtsch.-Ing. AXEL HANSMANN Dipl.-Phys. SEBASTIAN HERRMANN

Mönchen, September 23, 1968

Ha / KG

New description
(for disclosure)

Pressure fluid operated tool

The invention relates to a pressure medium-operated tool for rotating and axially moving a tool attachment back and forth, with a housing body, a pressure-medium-actuated pressure medium-actuated device which is arranged to be axially movable to and fro in the housing body Rotary motor for a tool spindle connected to it, a feed device mounted in the housing body, around the To move the rotary motor and the spindle forwards or backwards, as well as with a pressure medium source, the pressure medium of which the rotated motor through a passage through the tool

cd flows in. From US Pat. No. 3,039,443 there is a pneumatic drill co

- * became known, in which a rotary motor Q for driving a tool spindle is housed in a housing body. The rotary motor joins the back and forth movements of the tool spindle

blue JLfta. mm *? w & ia »a * a && totoämMm · *

Patent attorneys Dipl.-Ing. Martin licht, Dipl.-Wirtsch.-Ing. Axel Hansmann, Dipl.-Phys. Sebastian Herrmann

-2- U77A47

and gets the drive pressure medium fed through a line, axially through the housing body and through a feed piston likewise accommodated in the housing body passes through. At the rear end of the housing body, a valve slide is provided in the axial position, which in a first working position introduces pressure medium into the line leading to the rotary motor. The feed piston carries on his rear end now as an actuating device for the valve slide still a rod provided with a stop nut, which abuts the valve slide at the end of the feed stroke of the tool and adjusts it so that the pressure medium is supplied to the rotary motor and the feed piston stops. This stops the feed and the rotation of the tool spindle. The tool spindle and the associated rotary motor are then returned to the starting position by means of on the forward stroke of tensioned coil springs, which press on the feed piston in the reverse direction. When the feed- piston is returned to its original position, then it hits the valve slide with its rear end and returns it to its original position so that pressure medium can be supplied again.

From British patent specification 783 820, a pneumatic drill is known in which a in a housing body housed rotary motor is also supplied by an axial pressure medium line? the control of the pressure

90981 3/041 7

". 3 - U77A47

medium supply to the rotary motor and to a feed piston separated from each other.

Another pressurized medium-operated tool is known from US Pat. No. 2,869,403. There is used for feed the drilling spindle has a threaded spindle arrangement. She gets hers Drive by a planetary gear, and this also causes the rotation. By coordinating the drive speeds of a Feed spindle and a lead screw sleeve can be used to control the rotation and feed of the tool spindle. It is provided that that the rotation of the lead screw sleeve for the return stroke is restricted while the feed screw rotates quickly, to withdraw the tool. A valve slide is provided here for switching between feed in the working direction and retraction of the tool spindle a rod coupled to the drill spindle for joint movement is actuated. When the drill spindle is around a certain Amount is advanced, then a stop provided on the actuating rod strikes the valve slide and sets this around so that the tool spindle can be returned. In this known tool, a toothed gear arrangement and a valve arrangement cooperate in order to achieve the desired feed movement and rotary movement of the tool spindle Way to coordinate.

9098 1 3 / OA 17

The present invention is based on the object to get a pressure medium-operated tool of the type in question, in which only a simple valve arrangement for it ensures that the rotary movement of the rotary motor for the rotary spindle is maintained both when advancing in the forward direction and when retracting. Venn the drill spindle itself namely, when it is withdrawn, it does not turn, then this leads to a feeling of heat when it is withdrawn into the sides of the plundered Holes · cuts grooves. Also, only a single hose should be required to supply pressure medium to the tool and to control it "

To accomplish this task, a pressure medium-operated tool of the date assumed to be known at the beginning according to the invention, the arrangement is made in such a way that that · a valve is arranged in the passage which responds at the beginning of the forward movement of the rotary motor and the passage opens in order to continuously supply pressure medium to the rotary motor, and it together with dar during the forward and backward movement Drive the spindle continuously.

When the drill spindle moves out of its rest position, then the valve that is provided inside the passage in the faaektfrpar is opened immediately and lets the Rotary motor pressure medium flow so that it rotates. These

909813/0417. _

COPY

Circular movement continues until the return movement of the drilling spindle is complete. Only then does the rotary motor stop rotating. There is therefore no risk of the rotation of the drilling spindle being interrupted when it is withdrawn and sleeves being cut into the hole in an undesirable manner.

The invention is further characterized by a second valve, which in a first position with the pressure medium source connects to the rear end of the piston to move it forward. The arrangement is expediently like this taken that the second valve in a second working position the pressure medium source with the front of the piston connects to move it backwards. The arrangement is further characterized by a valve control device which the second valve "moves to its second position when the rotary motor reaches the end of its forward movement.

By these features of the invention it is achieved that the tool spindle automatically after reaching the desired drilling depth switches to retraction, but the rotary motor continues to rotate unabated.

An advantageous development of the invention is that the valve control device moves the second valve from its second to its first position when the pressure medium source is momentarily vented.

909813/0417

OOPY

Such an arrangement is particularly advantageous for remote control purposes. You need a back lift after appointment only briefly interrupt the supply of pressure medium in order to set a new work cycle in motion. This can be done either by operating a valve on the tool itself, or also by a valve arranged at any point in the pressure medium supply line.

Further features of the invention emerge from the subclaims.

The tool according to the invention is distinguished by a reliable business trip with a simple and light structure.

An embodiment of the invention is described with reference to drawings. In these represent:

1 shows a schematic representation of the pressure medium control system for a compressed air drill according to the invention;

FIG. 2 shows a part of FIG. 1, in which, however, the gate valve of the pressure medium control system is in its other position ingests;

3 shows a broken and cut-away view of the compressed air drill according to the invention;

Fig.% An enlarged sectional view along the line 4 of FIG. 3, with certain parts being cut away;

9098 1 3/04 1 7

Figure 5 is a longitudinal section of the rear half of the pneumatic drill |

FIG. 6 is a partial section along the line 6-6 in FIG. 4; FIG. 7 shows a partial section along the line 7-7 of FIG

FIG. 8 shows a partial section along the line 8-8 in FIG. 4j and

Figure; an enlarged section along line 9-9 of figure 5 *

The pneumatic drill ("Air-Feed-Drill") shown in the drawings has a body 1 _f to which an elongated extension cylinder 2 is attached 3 and 5. The inner cylinder 4 is closed at the rear end by the suction head 3 and protrudes from the front end of the outer cylinder 2. In the inner cylinder 4, a piston 5 is axially displaceable. A piston rod 6 extends forward from the piston 5 through a circular ring 7. The circular ring 7 is fastened in the inner cylinder 4 approximately in the middle between its ends.

The arrangement explained above forms two Druclmittelkanmern, which are separated from one another by the piston 5 and for the alternating Aufndee of a pressure medium, for example Compressed air serve so as to alternate the piston 5 in the interior.

909813/0417

cylinder k to move back and forth. The chamber located behind the piston 5 is called the forward stroke chamber 8 and the chamber located in front of the piston 5 is called the return stroke chamber 9.

The front end of the piston rod 6 is at the rear Fixed to the end of an ordinary air motor, which is slidable in the front half of the inner cylinder 4. It deals is a wing type air motor, the air motor 12 carries a conventional drill chuck 13 which extends from the front front end of the body 1 protrudes. Usually the drill chuck is powered by a set of planetary gears, not shown driven, which are connected between the air motor 12 and the drill chuck 13 and the rotational speed Reduce the air motor 12 for driving the chuck 13 to a usable value. The air motor and the drill chuck need not be described as they are used in pneumatic drills such as those in the Taylor patents, No. 2,674,098, Robinson, No. 2,857,789 and DeGroff, No. 2,860,531, are common are.

From the above it can already be seen that the air motor 12 rotates the drill chuck 13 while the piston 5 allows the motor 12 and the drill chuck 13 to reciprocate in the axial direction during operation. That and forward working cycle begins and ends when the piston 5 stops at the rear end of its path of movement. It exists from a forward stroke followed by a return stroke.

909813/0417

COPY

H77447

Pressure medium circuit of the engine

A simplified embodiment of this circle is shown in FIG Figure 1 shown. Generally speaking, this includes a pressure source, not shown, which is connected to a conventional three-way valve l6 connected main line 15 feeds. The valve l6 is by means of a hose 17 (shown in Figure 5) connected to a pressure medium inlet line 18 of the closing head 3. The inlet line 18 opens into a tube 19 attached to the front part of the end head 3, which tube extends through the piston 5 and the piston rod 6 extends forward. The piston rod 6 is hollow and has a central rod passage 20 that adjoins its front end opens into the pressure medium inlet 21 of the air motor 12.

The flow of the pressure medium from the tube 19 into the central rod passage 20 in the piston rod 6 is through a Engine valve 22 determines which one is in the center rod passage 20 is and is located so that it rests against the front end of the tube 19 and this closes when the Piston 5 is fully withdrawn. When the piston 5 its Vonvärtshub begins (as shown in Figure 1) the engine valve 22 is lifted from the front end of the fixed tube 19, and the pressure medium in the tube 19 can be in the Bar passage 20 of the air motor 12 flow so as to drive the motor and the chuck 13. This drive the motor 12

909813/0417

lasts for the remainder of the working cycle and is stopped when the piston 5 returns and the motor valve 22 can be placed on the front end of the fixed tube 19 again.

The special construction and mounting of the engine valve is shown in FIG. At the front end of the piston rod 6, a follower rod 25 is anchored with its front end. It extends through the central rod passage 20, the fixed tube 19 and (displaceably) through the end head 3 axially to the rear, and protrudes a considerable distance behind the end head. The follower rod 25 is thinner than the rod passage 20 and the interior of the fixed tube 19, so that pressure medium can flow through there. At the rear end of the end head 3, the follower rod 25 is surrounded by suitable seals so that the pressure medium cannot leak out of the fixed tube 19 at the rear.

The engine valve 22 has a resilient, rear end surface 26, which is to be placed on the front end of the fixed Rohres is intended. It is mounted on the idler rod 25 so that it can be displaced to a limited extent and is moved towards the rear placed under tension by a spring 27. The front end of the spring 27 is changed on the follower rod 25. This arrangement ensures that the engine valve 22 is pressed firmly against the tube 19 when the piston

909813/0417

- ii -

U77447

. 5 is withdrawn, and sox £ for a compensation all

Fluctuations between the piston position when it is fully back . ■

is pulled and the piston position - if the engine valve is on his seat.

Pressure medium circuit for the piston

To simplify the illustration of the pressure means " In the circle of the tool, FIG. 1 shows a part of the closing head 3 and the body 1 separated. Figure 1 thus contains only a schematic representation and does not show the true construction or arrangement of the Absohlufikopfes 3 and the elements assigned to him.

The final head 3 has a two-position adjustable gate valve 30, which in its bore 31 in the final head 3 is displaceable. Venn the gate valve 30 is in its forward position, pressure medium is supplied to the forward stroke chamber 8 and the return stroke chamber 9 at the same time relieved of pressure, so that the piston 5 is driven for its forward stroke. When the gate valve 30 is in its rearward position, the RUckhubkammer 9 pressure medium is supplied and at the same time the Vorwärtsshubkanmter 8 relieved of pressure, so that the piston 5 is driven backwards for its return stroke.

909813 / .0417

The gate valve 30 is prestressed in the forward direction by means of a spring 32 in the bore 31. When the gate valve 30 is in its forward position (shown in Figure i), the front and rear chambers 33 and 34, which are at the opposite ends of the gate valve 30, are connected to the inlet line 18 by means of intermediate channels 35 and 36 . The front intermediate channel 35 is connected to the front chamber 33 via a valve kl , and the rear intermediate channel 36 is connected to the rear chamber 3k via several small openings 37 in the gate valve 30.

When the gate valve 30 is in its forward position, the influx of pressure medium into the inlet line IS leads to the simultaneous influx of pressure medium to the front and rear chambers 33 and 3k of the gate valve. This avoids the build-up of a pressure gradient between the two chambers 33 and 3 ^. The gate valve 30 thus remains in its front position. When the pressure medium supply from the tool is switched off, the spring 32 normally causes the gate valve 30 to be moved into its forward position and held therein.

When the pressure medium has been supplied to both the front and the rear chamber 33 or 3k of the gate valve, the gate valve 30 is moved into its rear position by venting the rear chamber 3k, with a pressure gradient

909813 / 0-17

COPY

-13- U77447

is generated between the two gate valve chambers, which seeks to move the gate valve backwards. The venting the rear chamber 34 takes place in that a poppet valve 38 is pushed inwards, which is at the rear end the bore 31 lies and from the rear end of the termination head 3 protrudes. The poppet valve 38 is loosely attached in its guide bore 39, so that the pressure medium after Internal pushing of the shut-off member 40 and lifting from its seat can freely flow out of the rear chamber 34 into the atmosphere can. It flows through the clearance between the valve rod and its guide hole. The poppet valve 38 is referred to as a reversing valve because it allows the gate valve 30 to move to its rearward position and so the piston 5 can perform its return stroke.

If the gate valve 30 is in its rearward position, it can be moved back into its front position by venting the front chamber 33. This is done by the force of the spring 32. The front chamber 33 is vented by briefly interrupting the supply of pressure medium to the tool and venting the inlet line 18 by means of a conventional three-way valve ± 6 shown in FIG.

The front chamber 33 of the gate valve can also be vented by means of a poppet valve 41, which is attached to the side of the end head 3. The plate

909313/0417

COPY

valve 41 is similar to poppet valve 38 and is seated to and fro in a recess 42 of the closing head, which is connected to chamber 33 by a channel 43 . When the valve 41 is depressed, it simultaneously closes the end of the channel 35 opening into the recess 42 and ventilates the recess 42 which is connected to the front chamber 33 through the channel 43. The poppet valve 4i is referred to as a hand operated start valve because it can be used to start the tool into a new working period.

Forward stroke of the piston

When the gate valve 30 is in its front position shown in FIG. 1, the pressure medium can flow from the rear intermediate channel to a passage 45 through which flow occurs during the forward stroke and which leads to a needle valve 46 for setting the forward stroke. The needle valve 46 is used to adjust the pressure and allows the pressure medium to flow into a line 47 which leads to the forward chamber 8. When the gate valve is in its forward position, the return stroke chamber 9 is vented through a line which leads to a needle valve 49 for setting the rec stroke. The needle valve 49 has a connection to a return stroke channel 50, which in turn connects to a ventilation opening 51 by means of circumferential grooves 52 of the gate valve 30

909813/0417

Has. The needle valves 46 and 49 bind adjustable to the Ettstrttmen and outflow of pressure medium to and from the piston chambers β and 9 BU control and so the speed of the To change the forward stroke and «of the return stroke of the piston 5.

BüoVhnb of the piston

The Mitlauförstange 25, which protrudes from the rear of the closing head 3, has at its rear end a shoulder 54 on which a threaded bolt 55 is attached. When the piston 5 carries the idler rod 25 on its forward stroke, the bolt 55 finally strikes the reversing valve 38 and presses it near the bottom. The point of the forward stroke at which the reversing valve 38 depressed wlr4 _(can be changed. In this catfish is thus the length of the forward stroke of the piston by means of the threaded bolt 55 is adjustable by the sole setting of the threaded bolt.

As mentioned above, when the reversing valve is depressed, the gate valve rear chamber 34 is opened vented, so as to create a gap between the front chamber and the rear chamber 33 or 34 to build and the Ab « Let the locking slide go into its rear position

When the gate valve 30 is in its position shown in FIG is in the rear position, he reads the vent

909813/0417

51 and lets the pressure medium from the front chamber 33 through the return stroke channel 50 flow via the needle valve 49 into the line 48, which leads to the return stroke chamber 9 of the piston. At the same time, the forward stroke Kanmer 8 by the Line 47 relieved of pressure / 4. To do this, line 47 has over the circumferential grooves 52 of the gate valve 30 connection to the Vent 56.

When the gate valve 30 is in its rear position is, it interrupts the connection between the rear intermediate channel 36 and the forward hub channel 45, and that from the forward hub chamber 8 ejected pressure medium is diverted and not influenced by the needle valve 46. This makes it possible that the return stroke of the piston 5 is much faster expires as its forward stroke.

When the XoIben 5 reaches the end of its return stroke, he hai2 and remains in this position as long as he Gate valve 30 remains in its rear position (see Figure 2). The gate valve 30 remains in its rear position as long as the pressure in the forward stroke chamber is maintained.

In order to resume operation or to start a new working period of the tool, the VorwärtshubkaaMtr 33 vented. This is done either by means of the

909813/0417

COPY

- ι? - H77447

Three-way valve l6 or the manually operated start-up valve 41. This was discussed above. The manually operated start valve 41 is normally used when the drill itself is used by an operator and is not in a tool kit. Venn the drill is used together in a set with others, the drills are normally controlled by means of the three-way valve 16, which briefly interrupts the supply of pressure medium to the tools and that of the valve 16 to the Supply hoses 17 leading to individual tools are vented. The fact that the tools simply get back to work can be set that you interrupt the pressure medium supply is very desirable, since you only have a single Hose needs to supply pressure fluid and control the tools.

The special design of the line 48, which runs between the return stroke chamber 9 and the needle valve 49 for the return stroke, is shown in FIGS. The figure shows a longitudinal channel 59 which runs from the needle valve 49 into a radial passage 60. This opens into the annular space 6 ± between the outer cylinder and the inner cylinder 2 or 4. The annular space 6l has a connection to the return stroke chamber 9 of the piston by means of a second radial passage 62. The radial passage 62 is located at the front end of the return stroke chamber 9.

90981 3/0417

COPY

Various structural features

In certain cases it may be desirable to use the gate valve to trigger the return stroke of the piston from a distant point to allow it to return to its rear position * To this end, use is made of a pressure medium-actuated valve 64, which is shown in FIG. This valve 64 has a piston 65, which is in a bore of the end head 3 is displaceable and can be carried out by means of the hose 66 with the remote point from where the remote control should be connected. The valve 64 works like the other poppet valves 38 and 41 and is attached to the rear chamber 34 of the gate valve 30 is connected by means of a channel 67. When the valve 64 by supplying pressure medium is depressed to a piston 65 by means of the hose 66, it vents the channel 67 through the vent opening 68 into the free atmosphere.

The protruding part of the idler rod 25 and the bolt 55 cooperating with the reversing valve 38 are perfect encapsulated in a protective sheath 70 so that no unintentional injury from the movement of these parts can be done by an operator.

Operating mode.

Before commissioning the pneumatic drill and before supplying pressure medium the piston 5 is at the rear end

909813/0417 '

• a reciprocating movement, and the gate valve 30 rests in the BfijLner forward position. As the piston 5 is in its rear position> is the engine valve £ 8 in the bunk bar passage on its seat on ' and the fixed tube 19 »which protrudes axially forwards from the end head 3 closes.

In order to supply pressure medium to the tool, the valve 16 is simply ^{rotated into the} position shown in FIG. 1 and thus supplies pressure medium to the inlet line 18 of the closing head 3. This pressure medium is fed to the front and rear chambers 33 betf * 34 of the gate valve 30 at the same time. This is done via the intermediate channels 35 and 36 and has the effect that the gate valve 30 remains in its front position.

Venn the gate valve 30 is in its forward position is _v, the pressure medium flows from the rear Zwisohenkanal 36 via the gate valve 30 in the Vorwärtshubkanal k $. The channel 45 conducted the pressure medium to the needle valve 46 for the foreword stroke, where it is precisely measured. From there, the pressure medium flows through the line 47 into the forward stroke chamber 8, so that the piston 5 is driven for its forward stroke. Venn the gate valve 30 is in its forward position, also takes place

i ■ ''' a venting of the return stroke chamber 9 »This happens on ^: Λ> - ·· . <

9098 13/0417

following: line 48, needle valve 49, return stroke channel 50, circumferential grooves 52 of the gate valve 30 and ventilation, opening 51.

During the first part of the forward stroke of the piston 5, the engine valve 22 is removed from the end of the fixed tube 19 lifted off so that pressure medium can flow to the motor 12. The motor then drives the chuck 13 and one of it held chisel. The chuck 13 is thus rotated and axially advanced at the same time on its forward stroke. the The speed of the forward stroke can be adjusted by means of the needle valves 46 and 49.

When the piston 5 advances on its forward stroke, the follower rod 25 carries the threaded bolt 55 forward until it finally touches the reversing valve 38 and depresses. Depressing the valve 38 leads for venting the rear chamber 34 of the gate valve 30, so that the pressure medium in the front chamber 33 den The gate valve 30 drives into its rear position (see Figure 2).

In its rear position, the gate valve blocks the ventilation opening 51 and lets pressure medium out of the flow out front chamber 33 to the return stroke channel 50 and via the needle valve 49 for the return stroke. The needle valve 49 measures the pressure medium and lets it into the line

909813/0 417

COPY

48 flow through which it is guided to the return stroke chamber 9. This leads to a reversal of the movement of the piston 5> so that it begins its return stroke. At the same time, the forward stroke chamber 8 of the piston 5 is vented to the free atmosphere via the line k7, the circumferential grooves 52 of the gate valve 30 and the vent opening 56,

The rotary motor 12 continues to rotate the chuck 13 during the return stroke of the piston 5.

When the piston 5 ^a m rear end holding its return stroke, contacts the engine valve 22 its seat and closes the front end of the fixed tube 19, so that the pressure medium supply is interrupted to the swing motor 12, and this is stopped. The gate valve 30 then remains in its rear position until it is desired to put the tool into operation again.

The tool can be restarted in two ways, either by depressing the manually operated starting valve kl or briefly interrupting the supply of pressure medium to the tool by actuating the three-way valve 16. Both possibilities lead to the pressure medium being discharged from the front chamber 33 of the gate valve, so that the spring 32 can move the gate valve 30 back into its front position. If the tool is closed by actuating the three-way valve l6 or

909813/0417 _copY

-22- 147744?

if pressure medium is supplied again by closing the starting valve kl , the tool begins a new forward stroke. The following work cycle corresponds to the previous work cycle .

Although only one preferred embodiment of the invention has been shown and described in detail, it goes without saying that the basic idea of the invention can be modified and changed in some respects The spring attached to the piston can be withdrawn. The novel valve arrangement for the 'pressure medium motor 12 can also be used in other piston drives and piston control devices. It is also possible to use the novel shut-off element arrangement for the piston in connection with other types of pressure medium circuits for the rotary motor 12.

9098 13/04 17

Claims (1)

(for disclosure) ( 1. \ Pressure medium-actuated tool for rotating and axially moving a tool attachment back and forth, with a housing body »a pressure-medium-actuated rotary motor, arranged axially to and fro in each housing body, for a tool spindle connected to it, a feed device mounted in the housing body, around the rotary motor and to move the spindle forwards or backwards, as well as with a pressure medium source, the pressure medium of which flows to the rotary motor via a passage passed through the tool, characterized in that a valve (22) is arranged in the passage (19), which at the beginning responds to the forward movement of the rotary motor and opens the passage (19) in order to continuously supply pressure medium to the rotary motor and to continuously drive it together with the spindle during the forward and backward movement. 909813/0417 fclfilLe documents JArt. 7 £ 1 para. 2 Hs, 1 sow 3 of theändexusgtgaa. v. 4 * 9. l £ Patent attorneys Dipl.-Ing. Martin Licht, Dipl.-Wirtsch.-Ing. Axel Hansmann, Dipl.-Phys. Sebastian Herrmann if 2. Pressure medium-operated tool according to claim i, characterized by a second valve (30) which is in a first Position the pressure medium source with the rear end of the piston (5) connects to move it forward. 3. Pressure medium-operated tool naoh claim 2, characterized in that the second valve (30) in a second Working position connects the pressure medium source with the front of the piston (5) to move it backwards. 4. Pressure medium-operated tool according to claim 2, characterized by a valve control device (38) which second valve is moved to its second position when the rotary motor (12) reaches the end of its forward movement. 5 * Pressure medium-operated tool according to claim 4, characterized in that the valve control device (38) moves the second valve (30) from its second to its first position when the pressure medium source is momentarily vented (16, kl). 9 0 9813/0417 ORIGINAL IMSi ³ ECTEO V " 6. Pressure medium-operated tool according to claim 1, characterized in that the passage (19) extends through the tool body (6) and the piston (5) extends to direct pressurized medium to the rotary motor, and that the valve (22) is carried by the piston. 7. Pressure medium-operated valve according to claim 6, characterized in that the passage (l9) consists of a tube, which extends forward through the piston (5 »6) so that the piston (5) is hollow and slidable on the tube (19), that a hollow piston rod (6) connects the piston (5) and the rotary motor (12), and that the valve (22) inside the piston rod (6) so that it closes the front end of the tube (.19) when the piston (5) has reached its "backward" starting position. 8. Pressure medium-operated tool according to claim 2, characterized in that the pressure medium source with the second Valve (30) is connected via a three-way valve (l6) and a single line (17), and that the three-way valve is either Can introduce pressure medium into the main line or vent it. 9. Pressure medium-operated tool according to claim 2, characterized in that the second valve (30) is in a bore of the body (i) sliding gate valve (30) having first and second chambers (33, 34) at opposite ends is that a spring (32) normally controls the gate valve 9 0 9813/0417 -r- H77447 pushes into its first position and towards the first chamber, that a passage (35 »36) introduces pressurized medium into both chambers (33, 3 ^), so that the gate valve (30) remains in the first position, and that a device (55 »38) on the end point of the forward movement of the piston is responsive to vent pressure medium from the second chamber, so that the pressure in the first chamber Moves the gate valve into its second position, and the backward movement of the piston is also initiated, and that the gate valve (30) is moved back into its first position only by the fact that the pressure medium in the first Chamber is vented. 10. Pressure medium-operated tool according to claim 9, characterized characterized in that the first chamber (33) is simply characterized is vented that the main line to the tool is vented. 11. Pressure medium-operated tool according to claim 10, characterized in that there is a housing body (l) at the rear end aes the attached pipe (19) through the compressed air piston (5) in the direction of the compressed air motor (12) until it is close to its compressed air inlet extends that a follower rod (25) attached to the air motor extends from the air motor through the tube (19) and extends outwardly through the rear end of the housing so that near the inlet end to the air motor (12) there is an annular shape. 9098 13/0417 . _r . K77447 ges shut-off element (22) for closing the opening of the pipe (19) is attached to a backward movement of the follower rod on this that one for feeding the air motor (12) serving drying air line (18) on the back of the housing (i) ■ it is connected to the pipe (19) and that two compressed air lines (47, 48) for reciprocating the air piston and of the air motor closed on it - !! on the front resp. The back of the compressed air piston are connected. 12. Compressed air drill according to claim 11, characterized by one near the rear end of the housing on the follower rod (25) attached stop device (54, 55) for the Ventilation for switching the compressed air supply to one connected to the compressed air lines (47, 48) of the compressed air piston Control chamber (53, 34). 13. Compressed air drill according to claim 11, characterized through a single main line (l5) i which via a valve (16) through the compressed air line (18) to the compressed air motor the pipe (19) and via the control chamber (33, 34) with the Compressed air lines (47, 48) for the compressed air piston is connected. 909813 / 041.7