US 3111053 A
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Description (OCR text may contain errors)
Nov. 19, 1963 B. o. SVENSSON 3,111,053
LATERALLY AND ANGULARLY ADJUSTABLE coumuc FOR TOOL RECIPROCATING MECHANISM Filed March 25. 1958 2 Sheets-Sheet 1 I r a h l! 51 I 1 30 3&
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ATTORNEYS Nov. 19, 1963 B. o. SVENSSON 111,053
3 LATERALLY AND ANGULARLY ADJUSTABLE COUPLING FOR TOOL RECIPROCATING MECHANISM Filed March 25. 1958 2 Sheets-Sheet 2 INVENTOR v BIRGER OSTNESON ATTORNEYS United States Patent Ofiice 3 ,1 1 19 6 3 Patented N ov. 19, 1963 3,111,053 LATERALLY AND ANGULARLY ADJUSTABLE COUPLING FOR TOOL RECIPROCATING MECH- ANISM Birger Oskar Sveusson, Smedsgatan 12, Sandviken, Sweden, assignor of one-half to Erik M. Lorentzon, Bollnas, Sweden Filed Mar. 25, 1958, Ser. No. 723,638 3 Claims. (Cl. 83-124) The present invention refers to presses and similar machine tools, particularly of the type operating with a so called pillar stand, i.e. press, punch, cutting or other tools movable towards a fixed member in two or more guides.
This type of machine has hitherto exhibited various undesirable features. In connection with the mounting of a pillar stand in an eccentric-shaft press, the connection between the upper or movable part of the pillar stand and the driving arrangement or press head of the eccentricshaft press comprises a cylindrical mounting stud in the upper part of the pillar stand. The stud is clamped down in a V-groove in the press head. Depending upon the quality of the V-groove, the mounting stud may be forced into a more or less oblique position in the mounting process, i.e. obtain an angular error relative to the pillars of the stand. Furthermore, the direction of the movement of the press slide of the driving arrangement, which direction should ideally, in the case of a pillar stand, be parallel with the guiding pillars, may depart from this parallelism owing to the properties of the press slide and its guides and/ or of the properties of the press table and the inclination of its surface relative to the press slide and the V-groove of the press head. Similar objectional qualities may also develop in operation owing to resiliency in the machine frame. These drawbacks occur normally in eccentric'shaft presses owing to the constructional principles and the often very heavy work required of such presses. As far as the pillar stand and the tool mounted in it are concerned, they lead to increased wear, play and an uncontrollable deviation with regard to the adjusted tool play, which in its turn causes increased tool wear and a deterioration of the punched product. Furthermore, the conventional construction of eccentric-shaft presses and the use therein of a pillar stand with the above-described ordinary type of mounting stud is technically incorrect, as such a combination results in a guided motion. In connection with modern punching techniques, the importance of the tool play for tool wear and quality of the punched product has been more completely understood. The ideal tool plays decided on for each particu lar case should be adhered to with close tolerances. Owing to these high demands on precision, the tool and the pillar stand then become very expensive. In view of these facts, the importance of the disadvantages of the press constructions referred to above with regard to the tool and the punching process will be obvious.
Attempts have been made to remove these objections with the aid of couplings between the driving mechanism and the upper part of the press, through which some angular movement was made possible, but since there is also a certain transverse movement between the elements in question under these operating conditions, these couplings have not solved the problem.
The principal object of the present invention is to remove the objections referred to above and to provide satisfactory freedom of angular as well as transverse movement between the members of the coupling, thereby to eliminate asymmetrical stress, increased wear, play and undesirable deviations in the tool play. A further object is to provide a coupling of limited dimensions, which can be installed on the majority of existing types of pillar stands or the like.
According to the present invention, the coupling comprises two members connected with the driving mechanism and with a tool holder, respectively, as well as an intermediate member positioned between the said two members and having on opposite faces thereof concave supporting surfaces adapted for contact with correspondingly shaped convex portions of the said two members.
My invention may be more fully understood by direct reference to the drawings, wherein:
FIG. 1 is a schematic side view of a pillar stand with a coupling according to the invention mounted therein,
FIG. 2 shows the coupling on a larger scale in vertical section along the line 2-2 of FIG. 3,
FIG. 3 shows the coupling as viewed from above, and
'FIG. 4 is a vertical section through a pillar stand having a modified form of coupling.
FIG. 1 shows a pillar stand with a coupling 11 connected to the upper part 12 of the stand. The fastening of the coupling 11 in the press head 14, which serves as the driving mechanism, takes place in a V-shaped groove by means of a clamp 13 of similar shape. The desired function of the coupling is, during unsymmetrical movements of the press head 14, to compensate for angular and positional errors, thereby enabling the pillar stand and the tool mounted in it to operate in the desired way without the disadvantages referred to above.
The construction of the coupling is apparent in more detail from FIGS. 2 and 3. 15 is a mounting stud, which is attached to the press head 14 in the manner referred to above. 16 is an engagement stud screwed into the upper part 12 and locked by means of a stop screw 17. The mounting stud l5 and the engagement stud 16 make contact with an intermediate member assumed to be in the form of a disc 18 having two concave supporting surfaces adapted for cooperation with corresponding convex surfaces 19, 29 of the mounting stud and engagement stud, respectively. This makes possible particularly good contact between the corresponding surfaces, which may be semicylindrical but are preferably spherical. The surface structure of contacting surfaces is preferably similar or identical. The result is substantially decreased wear and satisfactory freedom of not only angular but also transverse movement between the mounting and engagement studs for an asymmetrical position of the intermediate member 18, these conditions being far from infrequent for the reasons stated above. In the present case, the engagement stud is attached to a ring fastener 21 comprising two halves by means of a number of screws 22, the ring fastener in its turn being adapted to contact a resilient member, such as a rubber ring 23 or the like, which is at the same time in contact with a flange provided in the engagement stud. This construction provides damping of movements that may take place between the mounting and the engagement stud.
The supporting surfaces 19 and 24 of the studs may be constructed for the purpose of wear reduction of hard metal, such as sintered tungsten carbide or the like with an admixture of a suitable binder, such as cobalt, steel, or the like. The same preferably also applies to the intermediate disc.
FIG. 4 illustrates the possibility of using the coupling according to the invention also for pillar stands with combined tools adapted to eject the finish work at the end of the operation to be performed on it. Ejector pins 24 and 25 required for the ejection extend axially through the engagement stud 26 and the mounting stud 27 as well as the intermediate member 28. The latter is provided with a central hold 29 of somewhat larger diameter than the pins 24 and 25. For the rest, both the studs 26 and 27 and the intermediate member 28 are provided with spherical support surfaces as described above. Ring fastener 21a and ring 230 are also similarly provided. The ejector pins 24 and 25 are in end-to-end abutment at half the height of the intermediate member, whereby the pins 24 and 25 can bend at this point and do not hinder an angular displacement of the longitudinal direction of the en-\ gagement stud with respect to that of the mouting stud.
Associated with lower ejector pin 24 is plate 3% and ejector transfer pins 31 acting on upper press tool 32. During the pressing operation, a work blank is inserted between tool parts 32 and 33. Upper press part 34 is then moved downward against press part 35, and the blank is thereby pressed between the tool faces. Pins 36 and openings 37 form corresponding alignment means. Upon completion of the pressing stroke, upper tool 32 is moved upwardthe displaceable amount shown. Pins 31, plate 30, and ejector pins 24, 25 move correspondingly upward. During the return stroke of upper press part 34, suitable means are provided for moving ejector pin 25 downwardly thereby downwardly moving tool 32 and ejecting the finished work product. Similarly, during the return stroke, spring means 38 urge stripper plate 39 upwardly to strip the lower tool part 33.
The embodiment of the invention described above is obviously only an example among a great number of constructive embodiments that are possible within the spirit and scope of the invention, the possibilities of varying the constructional features without departing from such spirit and scope being unlimited. The coupling can be used, for instance, in machines having two members performing rectilinear movements relative to each other for controlling these mutual displacements irrespective of whether the displacements are vertical or not.
What is claimed is:
1. In presses and similar machine tools, a coupling for transferring a reciprocating pressure force between a driving mechanism and a tool holder in the form of a pillar stand, and including a displaceable upper member operatively connected to the driving member and reciprocating in response to the driving member, the coupling comprising a wear-resistant mounting stud fixed to the upper member for reciprocation therewith and defining a convex spherical end surface transverse to the direction of reciprocation of the upper member and mounting stud; an engagement stud operatively fixed to the tool holder for transferring of movement to the tool holder and defining a supporting surface in the form of a convex spherical surface in axial alignment with the first convex spherical surface along the direction of reciprocation; spacing means enabling the mounting stud to maintain a spaced relationship with the engagement stud to permit limited lateral and angular movement relative thereto with respect to the direction of reciprocation; and an intermediate member disposed between the convex end surface of the mounting stud and the supporting surface of the engagement stud to transmit the reciprocation of the upper member and mounting stud to the engagement stud and the tool holder, the intermediate member defining on opposite sides thereof complementary concave spherical surfaces contacting the respective convex spherical surfaces of themounting stud and the engagement stud.
2. The coupling according to claim 1 wherein one of the studs includes a collar coaxial with the respective convex spherical surface, and the other of the studs includes an integral sleeve member freely surrounding the one stud, and the spacing means comprises a ring fastener mounted on the sleeve member and spaced from the collar, and a resilient elastic ring mounted in the space between the ring fastener and the collar.
3. In presses and similar machine tools, a coupling for transferring a reciprocating pressure force between a driving mechanism and a tool holder in the form of a pillar stand, and including a displaceable upper member operatively connected to the driving member and reciprocating in response to the driving member, the coupling comprising a wear-resistant mounting stud fixed to the upper member for reciprocation therewith and defining a convex spherical end surface transverse to the direction of reciprocation of the upper member and mounting stud; an engagement stud operatively fixed to the tool holder for transferring of movement to the tool holder and defining a supporting surface in the form of a convex spherical surface in axial alignment with the first convex spherical end surface along the direction of reciprocation, the engagement stud being in a spaced relationship with the mounting stud to permit limited lateral and angular movement relative thereto with respect to the direction of reciprocation; an intermediate member disposed between the convex end surface of the mounting stud and the supporting surface of the engagement stud to transmit the reciprocation of the upper member and mounting stud to the engagement stud and the tool holder, the intermediate member defining on opposite sides thereof complementary concave spherical surfaces contacting the respective convex spherical surfaces of the mounting stud and the engagement stud; and a pair of ejector pins, one extending centrally through the said mounting stud and the other extending centrally through the said engagement stud, the said pins being in end-to-end abutment Within a central hole defined by and extending through the said intermediate member between the studs.
References Cited in the file of this patent UNITED STATES PATENTS 336,335 McDonald Feb. 16, 1886 769,955 Osswald Sept. 13, 1904 1,425,083 Farrell Aug. 8, 1922 1,782,633 Schiltz Nov. 25, 1930 1,902,054 Ballard et al Mar. 21, 1933 2,035,978 Parker Mar. 31, 1936 2,547,518 Benjamin et al Apr. 3, 1951 2,547,594 Ohlsson Apr. 3, 1951 OTHER REFERENCES American Machinist, published by McGraw-Hill Publishing Co. on November 21, 1946.