The present invention refers to a machine for tooling internal grooves generally in holes of pieces for hydraulic flow control, preferably applicable to hydraulic steering components. 5. As it is known to those persons skilled in the art, one of the components of hydraulic steering comprises a valve of the rotating type for controlling the hydraulic flow, a central rotor having a cylindrical configuration is mounted in the valve in an

10. oscillating form in respect of the inner part of the spindle.

Coincidental grooves are provided inside the spindle and the rotor, and depending upon the relative oscillating movement between rotor and

15. spindle, it is obtained control of the hydraulic flow which passes through the holes existing in the assembly.

Previously, in order to perform notching of the spindle, pieces having an open end have been used, the utilization of a sealing ring fastened

20. by welding thus becoming necessary.

Despite of largely used, the fact is that such a method of spindle notching shows some deficiencies such as the complexity and the number of steps until obtaining the piece in question.

25. Another deficiency shown by the method of the prior art refers to the impossibility of detecting defects in the mentioned spindle before its mounting on the hydraulic steering assembly. Defects eventually shown will only be detected during test of the

30. assembly, i.e. at the occasion the whole hydraulic steering

system is already mounted. Such an inconvenient ends by creating high extra costs, as the assembly having a defective piece has to be disassembled in order to permit replacement of the defective element and then re-assembled to be used during new tests. In such a regard, a high level of refusal in the spindle manufacture has been observed resulting from the fact that the sealing ring sets itself free during grinding operation of the spindle.

As one can note, all , disadvantages mentioned above refer to the fact that the equipments of the prior art are unable to produce grooves over spindles, unless said spindles have an open end, which means in practice the need of obtaining a compound piece that is vulnerable to all defects possible to result from , the addition of a complementary part.

It should be pointed out that the conventional spindle notching operation even if dissatisfactorily is still carried out by industrial equipments of a large size, expensive, and of a high , constructive and operational complexity, thereby causing high maintenance cost.

It is one objective of the present invention to provide a machine for tooling ^* internal grooves in pieces capable of allowing components for , hydraulic steering systems, preferably spindles to be obtained without the need of opening their ends for the tooling operation.

Another objective of the present invention is to provide a machine for tooling , internal grooves in pieces capable of allowing exclusion of the step which seals the end of said piece by juxtaposition of a sealing ring fastened by welding.

It is still another objective of the present invention to provide a machine for tooling , internal grooves in pieces capable of obtaining an internally grooved piece having strong and monobloc

constructivity.

Finally, it is still another objective of the present invention to provide a machine for tooling internal grooves in pieces having simple construction and operation, thus enabling considerable reduction of the maintenance costs, besides better and safer operation.

These and other objectives and advantages of the present invention are achieved by a

10 machine for tooling internal grooves of the type comprising a structural body on which a set of two carriages having synchronized movement one in relation to the other is mounted; said two carriages being positioned one above the other, the upper carriage being responsible for the

15. fastening of the piece to be machined, and then describing a longitudinal movement; in the inner part of the upper carriage, an indexable shaft is mounted on conical bearings, a spindle capturing caliper is provided inside said indexable shaft; said caliper being mounted by screwing in a 0 set including a dragging tube which serves as limiting part against opening of the caliper; opening of the calipe. is thus obtained by means of a hydraulic cylinder operated lever which causes the springs to be compressed against a flange which allows axial displacement of the dragging tube, 5 so that disconnecting of the hydraulic cylinder allows the springs to act against said flange, as well as the caliper/dragging tube assembly to be dragged backwards and the caliper to enter into the conical portion of the indexable shaft, thereby firmly fastening the spindle to be 0 machined, said caliper having 360° rotation movement in respect of its axial shaft, in such a way that after tooling of each groove an electrical motor is operated, a crown and pinion causing to the caliper 60° rotation movement.

The present invention will 5 hereinafter be described in respect of the attached drawings in which:

Figure 1 shows an upper schematic view of the machine for tooling internal grooves having indicating arrows as to the possible movements of the upper and lower carriages; Figure 2 shows a partially cut lateral view of the top portion of the machine having indica¬ ting arrows as to the possible movements of the upper carriage; , Figure 3 shows a partially cut frontal view of the top portion of the machine having indica¬ ting arrows as to the possible movements of the lower carriage; Figure 4 shows a partially cut upper view of the , upper carriage showing the positioning of the spindle during tooling of the grooves; Figure 5 shows a sectional view according to line

AA of Figure 4; Figure 6 shows a sectional view according to line , BB of Figure 4; Figure 7 shows an enlarged view of one end of the spindle which is being machined by the tool which describes an elliptical movement; and , Figure 8 shows a sectional schematic lateral view of the machine for tooling grooves object of the present invention.

According to the attached illustrations the machine for tooling internal grooves , object of the present invention is constituted by a structural body E on which a set of two superimposed carriages 1 and 2 is mounted, said carriages having synchronized movement between them according to the axial and transversal directions of the structural body E. The set , of two carriages 1 and 2 being responsible for supporting caliper 3 to which spindle F to be cut is fastened.

Upper carriage 1 which is responsible for the longitudinal displacement of spindle F shows in its inner part an indexable shaft 4 mounted on conical bearings 5 in whose internal part caliper 3 is guided to attach spindle F to be machined.

Caliper 3 retaining spindle F is mounted in the inner part of indexable shaft 4 by means of a screw 6 together with a dragging tube 7 which serves as limiting to the opening of the caliper 3. , Opening of caliper 3 is carried out by a lever 8 hydraulically operated by a cylinder 9 shown by Figure 1. Driving cylinder 9 causes the set of springs 10 to be pressed by flange 11 arranged in the articulating end of lever 8 and around dragging tube 7, thus allowing movement of such a tube, and consequently opening of caliper 3.

Disconnecting of hydraulic cylinder 9 enables the power of the set of springs 10 to push flange 11 and consequently dragging tube 7 backwards, , whereby causing caliper 3 to enter into the conical portion of the indexable shaft 4, thus assuring fastening of spindle F adapted therein.

Although caliper 3 retains spindle F axially in respect of dragging tube 7, its 360° rotation is performed by an electrical motor M in respect of its axial shaft, together with crown 12 and pinion 13 along with spindle F, so as it is obtained tooling of six 60° equidistant grooves or channels C in the inner part of spindle F.

A divider 14 is also provided to obtain equidistant spacing between the tooled grooves C of spindle F which is under machinery. Said divider 14 including an electric coil B which pulls lever 15 against the spring power, said lever 15 being angularly retained by , a pin 16. As moved by coil B, lever 15 releases indexable shaft 4 for a partial rotation predetermined by divider 14.

After being de-energized coil B releases pin 16 which in its turn sets lever 15 free to return to the contact with the periphery of a partition disc 14 which is still describing a rotating movement around its 5. axial shaft as a result of the actuation of the electric motor. Partition disc 14 will be stopped in .its rotation as pin 16 forces a protuberance of lever 15 to fall into the next slot.

It is further provided a 10. rnicrorupturing device suitably positioned next to the partition disc 14 to indicate finish of the operation (six grooves) and to send a command to inform the end of the cycle.

In order to avoid efforts to

15. the electrical motor which actuates the partition disc 14 a clutch 17 is mounted between them, said clutch 17 being driven by springs 18 and supporting discs 19.

As previously mentioned, upper carriage 1 describes a longitudinal movement thanks to

20. the actuation of a shaft 32 whose lower end is engaged to a toothed wheel 33. Said shaft 32 including at its top part a device 36 which turns its simple rotational movement into an eccentrical rotating movement. Said movement can be adjusted through a special adjusting screw 37. The eccentricity

25. between the middle line of the actuation shaft 32 and the middle line of the eccentric device 36 is proportional to the length of groove C to be machined in the inner part of spindle F.

A runner 38 is positioned

30 between two oscillating bases 43 and acts as a connection means between the eccentric device 36 and upper carriage 1 , thereby controlling the beggining of groove C in the inner part of spindle F, that is to say closer or more remote to the end of spindle F.

35 Lower carriage 2 has transversal movement and during its displacement upper

carriage 1 positioned thereon is carried together.

Transversal movement of the lower carriage 2 is obtained by acuation of a shaft 39 similar to that used to obtain movement of upper carriage 1. Said shaft 39 also including adjustable eccentrical movement which defines the depth of groove C to be performed on spindle F, a toothed wheel 35 being positioned at the lower part of said axis 39.

The synchronized movement of , upper 1 and lower 2 carriages is obtained through a chain of simple links which acts over toothed wheel 34 of eccentrical shaft 32 of upper carriage 1, and simultaneously over toothed wheel 35 of eccentrical shaft 39 of lower carriage 2, a reducer being provided between the motor and eccentric , synchronized assembly.

Oscillating arm 21 actuating directly over a tool X and causing said tool to describe an elliptical movement by means of 180° working impulses following the anti-clockwise direction and being secured in , working position by an indexable pin 27 operated by a hydraulic cylinder, the positioning of the mentioned oscillating arm 21 being modifiable by means of an adjustable retainer 28.

Oscillating arm 21 is , mounted in eccentrical shaft 21a guided by bearings, a connecting rod 29 being positioned at one of its ends and engaging said oscillating arm 21 to a movable basis 30 having the function of positioning tool X to enable the work to be started and also to move the tool back after the , tooling operation is finished.

Tool X which will work on spindle F is positioned in a toolholder 20 provided in oscillating arm 21, said toolholder being adjustable in its longitudinal positioning by means of a supporting screw 22. , A set of pulleys 23 actuates over shaft 21a of said oscillating arm 21 which by means of

V-shaped belts receivesrotatioπ of an electrical motor, said oscillating arm 21 including balancing discs 25, 26 positioned between oscillating arm 21 and eccentrical shaft 21a.

Transversal movement of lower carriage 2 through eccentrical shaft 39 mounted on conical bearings rotates in anti-clockwise direction and is moved by toothed wheel 35. The channel eccentric which controls the channel depth is placed in the upper end of the

10, shaft. The channel depth may be controlled by means of an adjustment screw 40. On releasing nut 41 and rotating the screw clockwise, carriage 2 moves forward transversally to the middle line of the piece, and consequently the channel depth decreases. On rotating the screw anti-clockwise, the

15, inverse occurs to carriage 2, and a greater depth is obtained to the channel. As shown by Figure 3, shaft 39 rotates anti-clockwise, and at the beggining of the operation the eccentric is above its middle line.

After conclusion of each

20. groove C, an electrical signal is sent to the motor, coil B thus providing the next positioning to spindle F.

The controlling motor which operates the reducer and moves the eccentrical shafts thereby granting movement to the upper 1 and lower 2

25, carriages is of two speeds.

Therefore rotation movement of shafts for the first 180° of the eccentric is low (1 RPM), that is to say the part at which said carriages are at the tooling region, and for the next 180° of the eccentric

30 the rotation movement is high (6 RPM), that is to say the part at which the carriages are coming back to the initial position of the cycle.

After tooling each groove C, synchronism allows that during the return of the carriages

35 to the initial position, the piece rotates 60° thus being positioned to machine the next groove C.

The machine herein described allows tooling of internal grooves on spindles F which do not have an open end.

The piece constructed according to the present invention is considerably superior to that previously obtained in two parts and shows less problems and failures resulting from the manufacturing process.

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