FR2512880A1 - CONTROL DEVICE FOR PNEUMATIC DEVICES - Google Patents

Abstract

PNEUMATIC DEVICES. PNEUMATIC DEVICE CONTROL DEVICE OF THE TYPE INCLUDING A BODY 1 WITH A 6 PNEUMATIC MOTOR SUITABLE TO ROTATE IN BOTH DIRECTIONS, CHANNELS 66 AND 67 TO CONDUCT THE FLUID UNDER PRESSURE TO THE MOTOR, AN EXHAUST DUCT 65, CHARACTERIZED IN THIS THAT THE DEVICE INCLUDES A PISTON 33 CONNECTED TO A CONTROL UNIT 30 AND MOUNTED TO BE MOVED IN TWO OPPOSED DIRECTIONS FROM AN INTERMEDIATE POSITION IN WHICH THE INTAKE FLUID IS CLOSED, PISTON 33 INCLUDING MEANS FOR, WHEN 'IT IS FIRED, CLOSE THE FIRST CHANNEL, WHILE OPENING THE SECOND, AND WHEN IT IS PUSHED, CLOSE THE SECOND CHANNEL, WHILE OPENING THE FIRST.

Description

The present invention relates to a control device for

  pneumatic devices and more particularly

for screwdrivers.

  Pneumatic devices and in particular screwdrivers

  its generally consist of a body inside which is housed a pneumatic motor connected by a kinematic link to a drive member The body comprises a

  control device which makes it possible when

  send the fluid under pressure to the engine so that it

it is rotated.

  In many cases and especially in screwdrivers, it is desirable that the engine can be rotated either

  in one sense, in the opposite direction.

  The prior art knows various devices

  which selectively allow the fluid to be

  intake pressure through corresponding channels in the

  tor so that the rotor can be driven into one or

  in the other of the two directions of rotation.

  The known devices are relatively complex and generally consist of two distinct commands,

  that is to say from a first order which, when it is

  always allows rotation of the motor in a single

  sense, and a second command that must be operated simul-

  with the first command, so that the meaning of

rotation of the motor is changed.

  Such an arrangement is complex and impractical.

  The object of the present invention is to realize

  be a device for controlling pneumatic devices and

  screwdrivers which is simpler than those of the technology

  O nique earlier and in which it is not necessary to have two separate bodies to operate to change the

direction of motor rotation.

  The device which is the subject of the present invention is

  type comprising a body in which is housed a pneumatic motor

  able to rotate in two directions of rotation, said motor being connected by its output shaft to an organ

  to be driven, said body having a first channel for

  the intake fluid to the engine for rotation in one direction, a second channel for conducting the intake fluid to the engine for rotation in the opposite direction, and a conduit connected to the engine exhaust, and means for selectively controlling the admission of compressed air by one or the other of the channels, and is characterized in that it comprises, inserted on the channels, a movable piston connected to a single control member and mounted on so that it can be moved in one direction or the other from an intermediate position in which the inflow of the inlet fluid is closed, said piston having means for interrupting the passage of the fluid under pressure in the first channel when pushed into an external position, while allowing passage into the second channel, while in the opposite external position

  it interrupts the passage of the fluid under pressure in the se-

  cond channel, while allowing the passage-in the first

nal.

  Thanks to this arrangement, it is possible to realize a

  seems compact controls very easy to maneuver.

  According to a particular characteristic, the apparatus

  pneumatic tire is of the type comprising a handle and is

  in that the single control member is constituted by a swinging trigger at an intermediate point of its

law and connected to the piston.

  Thanks to this arrangement, an extremely simple control device is produced in which it suffices to press the trigger, in the vicinity of one end thereof, to control the rotation in one direction of the motor and, if the we want to control the rotation in the opposite direction, just exercise

  pressure on the trigger in the vicinity of its other extremity.

  you. According to a particular constructive characteristic, the piston comprises an axial bore in which extends a

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  fixed rod, the latter comprising between two stops two ron-

  delles between which is interposed a compression spring, each washer bearing against internal stops of the bore. Thus, a control device which is automatically returned to its

  initial position as soon as it is no longer requested.

  According to yet another construction feature

  the piston has at its periphery

  each carrying a throat in each of which is housed

  a torric joint, the beads forming between them

  grooves, so that the movement of the piston in one direction allows the supply of pressurized fluid for rotation to the left of the motor and the displacement in the other direction the supply of the fluid under pressure, for the rotation

to the right of the engine.

  According to yet another characteristic, the body comprises in the handle, a bore in which is mounted and fixed a jacket having holes communicating with the various channels and ducts, the piston being mounted movably

in the shirt.

  Finally, according to one last characteristic, the stem

  fixed on which are mounted the two washers between

  which extends a compression spring, is screwed into a tapping of a nipple integral with a wafer interposed between the bottom of the bore made in the handle and the end

corresponding of the shirt.

  The invention will now be described with reference to

  1 is an elevational view partially in section of a pneumatic apparatus comprising a control device according to the invention; FIG 2 is an enlarged sectional view of the control device in the right rotation control position of the engine, FIG 3 is a sectional view on a larger scale of the control device in the left rotation position of the engine.

  In Figure 1, there is shown a pneumatic screwdriver

  tick comprising a body 1 with a handle 2 provided with a

  connection 3 intended to be connected to a distribution hose

  compressed air The handle 2 also comprises a

  cavity 4 compressed air outlet with a silencer -

  In the body l is housed a pneumatic motor with

  pallets 6 which can rotate in both directions of rota-

  Such an engine is of a known technique and will not be

described in detail here.

  The rotor 7 of the motor is supported by two shaft ends 8 and 9, the shaft 8 being journalled in a bearing 10

  of the body, while the shaft 9 is carried by a bearing II.

  The shaft 9 is connected by a kinematic connection to a tool housed in the body 1 with the interposition of a torque limiter. The rotor 7 rotates in a stator 12 which has

  holes 13 constituting the exhaust and opening into a

14 of the handle 2.

  The motor 6 is closed by a flange 15 having a duct 16 opening into a duct 17 of a ring 18 and opening on the rotor 7 to form an inlet of the

fluid under pressure.

  In a housing 20 of the ring 18 is disposed a seat 21 of a valve 22 pushed into the closed position by a spring 23 inserted between said valve and the bottom of the

flange 15.

  The ring 18 has an opening 24 connected by a conduit 25 to a second fluid inlet under pressure in the stator (the conduit 25 is visible only partially on the

  drawing, which extends outside the cutting plane).

  before the pressurized fluid is passed through the conduit 16, the engine is turned to the left, and if, on the contrary, the pressurized fluid is passed through the conduit 25, the

motor turns right.

  The valve 22 is connected, by a rod 26 passing through the rotor 7, to the tool which is slidably mounted in the body, against the action of a spring, so that during screwing

  the apparatus can only function if it has been exercised

  pressure to open the valve 22.

  On the handle 2 is articulated on an axis 28 supported by a lug 29, a trigger 30 which comprises a finger 31 engaged in a notch 32 of a piston 33 having three beads 34, 35 and 36, each bead being provided

  a groove 57 in which is housed an O-ring 38.

  The beads 34 and 35 delimit between them a wide groove, a wide groove 41 extending between the beads 35 and 36. The piston 33 has an axial cavity 42 open at one end 43 and provided with a shoulder 44 in the handle is formed a bore 45 in which is mounted a sleeve 46 held by a nut 47 Between the bottom of the bore 45 and the corresponding end of the sleeve is inserted a plate 49 having a central threaded stud 50 in which is screwed the corresponding thread 51 of a rod 52 comprising

  at its free end a head 53.

  On the rod 52 are engaged two washers 54 and 55 and a compression spring 56 The washer 54 bears against the shoulder 49, while the washer 55 abuts against the free end of the stud 50 and secondly against a

  stop ring 57 fixed in a groove 58 of the piston 33.

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  In the handle 2 is made a channel 60 and the sleeve 46 has a series of holes 61 located in the right

of said channel.

  A second channel 62 opens to the right of holes 63 of the liner 46, said holes being located opposite a

  duit 65 opening into the cavity 14.

  Two ducts 67 and 66 are planned, the first

  plugging in a cavity 69 located behind the flange 15, while the second opens into a passage 68 formed between the ring 18 and the flange 15, the chimney 46 having holes 72 and 73 coinciding respectively with the conduitsq As seen at 1, the piston, in its rest position, occupies a position such that the channel 60

  compressed air inlet opens next to the groove 41.

  Thus the passage to the channels 66 and 67 is closed.

  In the piston 42 holes 71 are provided which

cilitate a residual exhaust.

  When you press on the lower part of the

  tent (see FIG 2), the piston 33 is moved in the jacket 46 in the direction of the arrow "f", and the intake fluid passes through the channel 60, the groove 41, the conduit 67 y the passage 68 and, if the valve 22 is open, through the opening 24, for

  power the engine running to the right, the exhaust is

  killing through the conduit 65, the hole 46, the groove 40 and the channel 62.

  If, on the contrary, one presses on the upper end of the trigger, in the opposite direction to the arrow "f'V (see FIG 3) the pressurized fluid arriving through the channel 60, passes through the groove 41, the conduit 66, opens into the cavity 69, through the ducts 16 and 17 to supply the motor in the direction

  3 o of the rotation on the left The exhaust is carried out by the

  65, the holes 46, the hole 63 and the channel 62.

  It will be noted that in the direction of rotation to the right of the engine, the residual air can escape through the holes 71, 73, to open into the groove 40 and the channel 62, while in the direction of rotation to the left, the residual air passes through the duct 67, the hole 72, the holes 71, the groove 40

and the channel 62.

  Such an arrangement is very functional

  safe and facilitates the use of the device.

  Of course, the invention is not limited to the mode

  realization of being described and represented on behalf of

  ra make many changes to the details without

  to get out of the scope of the invention.

R E V E N D I-C A T IO N S

  1 Device for controlling pneumatic devices such as screwdrivers, of the type comprising a body (1) in

  which is housed a pneumatic motor (6) capable of

  in two directions of rotation, said motor being connected by its output shaft (9) to a member to be driven, said body

  having a first channel (66) for driving the admixing fluid

  engine-driven for one-way rotation, a second channel (67) for driving the intake fluid to the engine for rotation in the opposite direction, and a conduit (65) connected to

  the exhaust of the engine (6) and means for controlling

  respectively the admission of compressed air by one or other of the channels, characterized in that it comprises, inserted on the channels (66, 67), a piston (33) movable, connected to a body of

  single control (30) and mounted so that it can be moved

  in one direction or the other from an indi-

  intermediate in which the arrival of the intake fluid is

  closed, said piston (33) comprising means for inter-

  to break the passage of fluid under pressure in the first compartment

  nal (66) when pushed into an extreme position while allowing passage into the second channel (67), while in the opposite extreme position it interrupts the passage of the

  fluid under pressure in the second channel (67) while

  puts the passage in the first channel (66).

  2 control device according to claim 1,

  and the type in which the body has a handle, characterized

  in that the single control member is constituted by a trigger (30) pivotally mounted at an intermediate point

  its length and piston linkage (33).

  3 Control device according to claim 1, characterized in that the piston (33) comprises an axial bore in which extends a fixed rod (52), the latter comprising

  between two stops (50, 53) two washers (54, 55) between

  a compression spring (56) is interposed therein, each spine bearing against inner stops of the bore

(44, 57).

  4 Control device according to claim 1, characterized in that the piston (33) has at its periphery beads (34, 35, 36) each having a groove (37) inwhich each housing is housed an O-ring (38), the beads forming between them wide grooves (40, 41) so that the displacement of the piston (33) in a direction allows

  pressurized fluid supply for the left-handed rotation

  motor, and moving in the other direction, the power supply

  pressurized fluid for rotation to the right of the

says engine.

    Control device according to the claims

  1, 2, 3 and 4, characterized in that the body has in the handle a bore (45) in which is mounted and fixed a

  shirt (46) having holes communicating with the different

  channels and conduits (60, 62, 65, 66, 67), the piston (33)

  being movably mounted in the liner (46).

  6 control device according to claim, characterized in that the fixed rod (52) on which are mounted the two washers (54, 55) between which extends a compression spring (56), is screwed into a tapping ( 50) of a nipple secured to a plate (49) inserted between

  the bottom of the bore (45) in the handle and the end

  corresponding mite of the shirt (46).