US3605479A - Forming press - Google Patents

Abstract

A FORMING PRESS IN WHICH THE FORMING ELEMENTS ARE DRIVEN BY A CRANK AND CONNECTING ROD. THE CONNECTING ROD IS DIRECTLY DRIVEN IN A FORMING STROKE BY A CRANK AND SUBSEQUENTLY OPERATES A LIFTING CAM CARRIED ON THE SAME

DRIVE SHAFT. THE CRANK ACTS THROUGH A BEARING OR SLIDE TO IMPART THE DRIVING FORCE TO THE FORMING ELEMENTS.

Description

p 1971 c. R. BRADLEE 3,605,479

FORMING PRESS Filed May a. 1968 4 Sheets-Sheet 1 [El INVENTOR Chomhze R. Brouflcc n% M0 144 arm/u iii 10mm Sept. 20, 1911 c. R. BRADLEE FORMING PRESS 4 Shouts-Sheet 2 Filed Ilay 8. 1968 Charms R-Bm n fi C. R. BRADLEE FORMING PRESS Sept 20, 1971 4 Sheets-Shoat 5 Filed May 8. 1968 Choxhzs R.Bmd\ee,'

BY 1% A W W ATTOR 529 Sept. 20, 1971 c. R. BRADLEE FORMING PRESS v 4 Sheets-Shoat 4 Filed May 8. 1963 DEGREES I mvawrox Chow-B5 R. Brmflee 96% Mb WW RNEY5 United States Patent 01 3,605,479 Patented Sept. 20, 1971 3,605,479 FORMING PRESS Charles Robert Bradlee, Cheshire, Conn., assignor to Textron, Inc., Providence, RI. Filed May 8, 1968, Ser. No. 727,404 Int. Cl. B213 9/18 US. Cl. 72-450 15 Claims ABSTRACT OF THE DISCLOSURE A forming press in which the forming elements are driven by a crank and connecting rod. The connecting rod is directly driven in a forming stroke by a. crank and subsequently operates a lifting cam carried on the same drive shaft. The crank acts through a bearing or slide to impart the driving force to the forming elements.

This invention relates to presses, and more particularly relates to machines of the type adapted to operate upon and form workpieces with a plurality of aligned plungers.

Machines of the type to which this invention pertains may generally be referred to as transfer presses and independent cam operated presses, and generally comprise a plurality of plungers extending vertically in side-by-side aligned relation each carrying a forming tool adapted to act upon workpieces successively moved along the punches. In an independent cam operated press each plunger and the forming tool carried there'by is generally operated by an individual one of a plurality of cams mounted on a drive shaft rotatably mounted above the plungers. In such machines, there is associated with each plunger a driving cam to drive the plunger downwardly on the workpiece, and a lifting cam to lift the plunger away from the workpiece. The invention may also be embodied in the type of machine referred to as a transfer press in which all of the plungers are carried in a ram which is driven downwardly by a driving cam, and raised by a lifting cam. In these types of machines the lifting, and particularly the driving cam, operate upon a cam follower to drive and lift the plungers.

The present invention provides a new and improved drive arrangement for machines of the type described which permits application of higher forming pressures to the plungers. This is achieved by utilizing a drive mechanism in which a crank provides the driving and forming force for the plungers. This arrangement permits higher forming loads without increasing the size or decreasing the life of the cams or followers.

Briefly stated, in one form of the invention, the drive shaft is formed with cranks. A bearing means is mounted to the cranks and is slidably received within a collar at one end of a connecting rod. On the driving stroke the forming force applied to the plungers is almost entirely applied by the crank. This construction eliminates driving cams and cam followers and further provides a more positively connected drive arrangement so that there is a direct connection between the plunger driving element and the drive shaft.

Accordingly, it is an object of this invention to provide a new and improved drive and lifting arrangement for devices of the type described.

Another object of this invention is to provide a new and improved crank and connecting rod drive for plungers in machines of the type described.

A further object of this invention is to provide a drive and lifting arrangement for a device of the type described which permits increases in capacity without increase in the size of the cams or reduction in the useful life thereof.

The features of the invention which are believed to be novel are set forth with particularity and distinctly claimed in the concluding portion of this specification. The invention, however, both as to its operation and organization together with further objects and advantages thereof may best be appreciated by reference to the following detailed description taken in conjunction with the drawings, wherein:

FIG. 1 is a front elevation of an independent cam operated press which embodies the invention;

FIG. 2 is a sectional view seen in the plane of lines 2--2 of FIG. 1;

FIG. 3 is an enlarged view of the mechanism of FIG. 2 showing the mechanism in a plunger lifting position;

FIG. 4 is a view similar to FIG. 3 but showing the mechanism in a plunger driving position;

FIG. 5 is a front elevation of a transfer press embodying the invention;

FIG. 6 is a sectional view seen in the plane of lines 66 of FIG. 5;

FIG. 7 is an enlarged view of a portion of the mechanism of FIG. 6;

FIG. 8 is a sectional view seen in the plane of lines 88 of FIG. 7; and

FIG. 9 graphically represents the movement of the mechanism of FIGS. 6 and 7.

An independent cam operated press embodying the invention is generally indicated by the reference numeral 10 which comprises spaced upright side frame members 11 and 12 with a horizontal die bed 13 and an upper cross frame member 14, a plurality of plungers 15 are vertically slidable in cross frame members 16 and 17 extending between side frame members 11 and 12. Each of the plungers 15 is adapted to carry a forming tool 18 at its lower end to cooperate with die 19 mounted upon die bed 13.

Each of the plungers is independently operated by a drive and lifting assembly 20, hereinafter more fully described. Such drive and lifting assemblies are each mounted to a shaft 21 driven by means of a pulley 22 from a motor 23. Shaft 21 is rotatably supported in side frame members 11 and 12 and at the end thereof carries a bevel gear 24 in meshing engagement with bevel gear 25 on a shaft 26. Shaft 26 at the lower end thereof carries a bevel gear 27 meshing with bevel gear 28 on shaft 29 which is rotatably carried by supports 30. Shaft 29 further includes thereon cams 31 which engage ejection pins 32 at each station to eject workpieces from the dies 19 on die block 13.

Shaft 21 is formed with eccentric cranks 33 thereon to which are mounted the driving and lifting assemblies 20. An arm 34 is associated with each plunger 15 and is, in turn, secured to a lifter rod 35. A second arm 36 is secured to the lifter rod in spaced relation to arm 34 and is adapted to be engaged by a lifting cam 37 so as to lift the plunger 15. As shown in FIG. 3, cam 37 is near the uppermost position and through arm 36 and lifting rod 35 has lifted arm 34 and plunger 15. The uppermost portion 39 of plunger 15 is secured in arm 34 and has an upper bearing surface or shoulder 40 adapted to receive a forming blow. Plunger 15 is driven downwardly by a ram 41 which is pivotally mounted to a connecting rod 42. Connecting rod 42 includes a collar 43 formed in two parts which define an inner circular track 44 which receives therein the outer periphery of a bearing member 45, also formed in two parts. As illustrated, bearing 45 is mounted to the crank eccentric to the center of bearing 45. Lifting cam 37 may be formed integral with crank 33 as shown in FIG. 1, or may be separately formed and mounted to the crank in fixed relation to bearing 45 by a key 52.

In operation, as shaft 21 is rotatably driven, bearing 45 rotates therewith and rotates within track 44 of collar 43. This will impart a reciprocating motion to connecting rod 42, whigh motion is a function of the length of crank.

33 on shaft 21 and the eccentricity of the center of bearing 45 with respect to the axis of crank 33. With this arrangement, the crank applies the driving force to the plunger.

As crank 33 moves toward its bottom center position, as shown in FIG. 2, the underside of ram 41 engages surface 40 of plunger 15 and drives it downwardly in a forming stroke. Ram 41 includes a pin-like projection 48 which rides in a bore 49 defined in the upper portion of plunger 15 and acts as a guide for ram 41 with respect to plunger -15.

In the view shown in FIG. 3, plunger 15 is being raised by motion of lifting cam 37. It will ultimately be raised until arm 34 is in the position indicated by the broken line 51. This lifting motion is fully under the control of lifting cam 37 since upward motion of ram 41 under control of motion of bearing 45 is not restrained in any way by plunger 15 or arm 34. This raising motion is a function of the contour of lifting cam 37, but cannot exceed the eccentricity of bearing 45.

In FIG. 4 the shaft 21 has rotated approximately one hundred fifty degrees from the position shown in FIG. 3 and has rotated approximately sixty degrees through the downstroke of plunger 15. As shaft 21 rotates, bearing 45 rotates therewith within collar 43 and crank 33 drives collar 43 and connecting rod 42 downwardly until ram 41 engages the top surface of plunger 15 and imparts a driving and forming force thereto. At this time, arm 34 and lifter rod 35 move downwardly to the position shown in FIG. 2. Thereafter, as the plunger reaches its bottommost position, lifting cam 37, upon further rotation of shaft 21 engages arm 36 and lifts lifter rod 35, and hence plunger 15.

The invention may also be embodied in other forms to obtain the desired motion. A transfer press is an apparatus similar to the independent cam operated press in that it is utilized for sequentially forming a plurality of articles. However, in the transfer press, all of the plungers are carried by a large ram and do not operate independently. However, the position of each plunger with respect to the press may be independently adjusted as shown in US. Pat. 3,358,591. The motion of the ram may be obtained from the invention as follows.

In FIG. a transfer press is generally indicated by reference numeral 70 and comprises a frame having upright side members 71 and 72, and a top cross-member 73. A die bed 74 carries a plurality of die blocks 75 thereon.

Slidably mounted between side frame 71 and 72 is a ram 76 carrying a plurality of plungers. A cross-bridging member 77 carries a plurality of frictional holding devices 78, one for each of plungers 79. Rotatably supported in side frames 71 and 72 and in journal members 80 and 81, supported from top-cross member 73, is a shaft 82. Shaft 82 is driven from a motor 83 mounted to the frame of press 70 through a pulley 84 on the shaft of motor 83, a belt 85, and a pulley 86 mounted to shaft 82. A pair of connecting rods 87 and 88 are pivotally connected to ram 76 about large pins 89 and 90, respectively, carried by ram 76. The connecting rods 87 and 88 are connected at their other end to lifting and driving mechanisms 91 and 91a, respectively.

As more clearly shown in FIG. 6 each of plungers 79 receives therein a threaded stud or shaft 92 which passes through an annular nut 93 threadably received in the upper portion of ram 76. Shaft 92 is further threaded at the other end thereof into a lifter rod 94 which is received in a frictional holding device 78. Lifter rods 94 are normally held in frictional devices 78 and move therein only when motion is imparted to the lifter rod or plunger by the motion of ram 76. Accordingly, with this arrangement the vertical position of nut 93 determines the travel of plunger 79. In operation, when ram 76 is ...-1driven.v downwardlythe under surface of nut 93abuts the upper surface of plunger 79 and through ram 76 applies a forming force thereto.

Therefore, the upstroke lash or clearance between the upper surface of nut 93 and the lower surface of lifter rod 94 may be adjusted by varying the position of lifter rod 94 on shaft 92. To adjust the plungers and thereby predetermine the bottom position of the plungers actuated thereby, nut 93 maybe threadably advanced or backed off with respect to the depth of the recess in which it is received in ram 76. It will be apparent that the deeper the nut is inserted into the recess the lower will be the bottom position of the punch or tool carried by the plunger.

Means are provided for insuring only linear motion of each of the plungers 79 in ram 76. Each of the plungers receives therein a headed bolt 95 which further provides a seat for a bushing-like member 96 disposed between the head of bolt 95 and the seat therefor 97 on plunger 79. A bearing element 98 is disposed around bushing 96 and slides in a channel 99 defined in a guide member 100 associated with each plunger 79. This arrangement prevents any turning motion of the plungers and maintains the plungers and any tool thereon in predetermined alignment with the associated die block 75.

Shaft 82 has cranks 101 and 102 about which are mounted a slide or hearing 103 (FIG. 7) which reciprocates in guides 104, 105 in the head 106 each of connecting rods 87 and 88. Bearing 103 is received in an opening defined by guides 104, 105 on upper wall and a lower bearing surface 117. The opening and guides are defined in a head or collar 106 which includes a member 107 secured to one side thereof as by bolts 108 and defining guide 105 for bearing 103.

Mounted atop collar 106 is a block 109 carrying a shaft 110 upon which are mounted cam followers 111 and 112. Mounted about portions 113 and 114 (FIG. 5) of the throws of crank 102 are lifting cams 115 and 116, respectively.

The lifting cams 115 and 116 upon rotation thereof act upon the cam followers .111 and 112 to lift rod 87 and, hence, ram 76, after the ram has been driven downwardly.

In operation, as shaft 82 is rotated it will drive bearing 103 through cranks 101 and 102 downwardly against surface 117 to the forming position shown in FIG. 6 and a tool and holder 118 therefor coacts with die block 75. Thereafter, upon continued rotation of shaft '82 the lifting cams 115 and 116 engage cam followers 111 and 112 and raise rods 87 and 88 and, hence, ram 76. On the downstroke, when bearing 103 bottoms on the lower surface 117 it imparts a downward driving force to connecting rod 87 and, hence, ram 76. This operation may be more fully understood by reference to FIG. 9.

FIG. 9' graphically illustrates the relation of the stroke of crank 102 to the stroke of cams 11-1 and 112. The vertical movement of the crank through 360 degrees of rotation thereof is sinusoidal with respect to rotation of the crank with a peak-to-peak amplitude of approximately seven and one-half inches. On the downstroke, cams 111 and 112 dwell until approximately sixty degrees of rotation, from top dead center. At approximately 80 degrees, bearing 103 engages surface 117 and forces connecting rod 87 downwardly. Motion of the cam 1.15 is made to follow that of crank 101 until about .240 degrees of rotation. From degrees lifting of connecting rod 87 is accomplished directly by carns 115 and 116. At approximately 240 degrees, cams 115 and 116 are programmed to dwell whereupon rotation of crank 101 draws bearing 103 upward between guides 104 and 105 and out of contact with surface 117. Connecting rod 87 at this point is controlled solely by cams 115 and 116. In FIG. 9 the vertical distance between the full line and the broken line represents the distance between bearing 103 and surface 117 at any degree of rotation of crank 101.

Accordingly, it is seen that in the forming stroke the connecting rod is driven by the crank and in the lifting stroke the connecting rod is driven by the cams.

If plotted, the movement of the ram 41 to arm 34 with respect to crank 33 in the press of FIGS. l-4 would exhibit a similar relationship.

Accordingly, it is apparent that in both presses the forming members are directly driven in the forming strokes by the cranks and thereafter the lifting cam comes into direct operation. These mechanisms allow the application of higher forming forces, elimination of a driving cam, and prolong the life of the lifting cams.

Accordingly, the objects of the invention set forth as well as those made apparent from the foregoing disclosure are efficiently attained. While a preferred embodiment of the invention has been set forth for purposes of disclosure, modifications thereto as well as other embodiments which do not depart from the spirit and scope of the invention may occur to others skilled in the art. accordingly, the appended claims are intended to cover all embodiments of the invention and modifications of the disclosed embodiments which do not depart from the spirit and scope of the invention.

What is claimed is:

1. In a forming press including a frame, guide means, a linearly reciprocating plunger in said guide means, a die bed positioned below said plunger, a drive shaft rotatably mounted in said frame above said bed, said drive shaft having a crank thereon, a connecting rod actuated by said crank to impart a forming force to said plunger, bearing means mounted to said crank for rotation therewith, said bearing means having a circular periphery, said connecting rod including a collar having a circular guide receiving said bearing for rotation therein so that upon rotation of said crank said bearing means rotates within said collar and imparts motion of said crank to said connecting rod, and means pivotally mounted to said connecting rod arranged to impart a driving force to said plunger.

2. In a forming press including a frame, a vertically reciprocal plunger, a die bed positioned below said plunger, a drive shaft rotatably mounted in said frame above said bed, said drive shaft having a crank thereon, a connecting rod actuated by said crank to impart a forming force to said plunger, bearing means mounted to said crank for rotation therewith, said bearing means having a. circular periphery, said connecting rod including a collar having a circular guide receiving said bearing for rotation therein so that upon rotation of said crank said bearing means rotates within said collar and imparts motion of said crank to said connecting rod, a ram on said connecting rod, and a bearing surface on said plunger adapted to be contacted by said ram.

3. The press of claim 2 further including a rod movable vertically in said frame, a first arm on said rod connected to said plunger, said ram being pivotally connected to said connecting rod and arranged to engage the top of said plunger and impart a forming force thereto.

4. The press of claim 2 wherein said plunger has a vertical bore defined therein and said ram includes a projecting pin received in said bore.

5. The press of claim 1 further including a rod vertically movable in said frame, a first arm connected to said rod and said plunger, a second arm connected to said rod and overlying said drive shaft, and a lifting cam on said drive shaft adapted to contact said second arm and lift said second arm and rod.

6. The press of claim 5 wherein said cam is mounted on said crank.

7. The press of claim 6 wherein said cam is integrally formed with said bearing member.

8. The press of claim 5, said cam is so contoured and said crank is so dimensioned that said ram is lifted a greater distance than the distance said ram drives said plunger.

9. The press of claim 1 wherein said bearing member is mounted to said crank eccentric to the center thereof.

10. The press of claim 5 wherein said first arm includes a well therein adapted to receive said ram.

11. In a forming press including a vertically reciprocal forming member, a die bed positioned below said forming member adapted to receive workpieces for forming, a horizontal drive shaft supported in said frame, said drive shaft having a crank thereon, a connecting rod actuated by said crank to impart a forming force to said forming member, bearing means mounted to said crank for movement therewith, said connecting rod having guide means receiving said bearing means for movement therein so that upon rotation of said crank said bearing means moves within said guide means and imparts motion of said crank to said connecting rod, a lifting arm constructed and arranged to lift said forming member, and a lifting cam mounted to said crank for rotation therewith to lift said forming member through said arm.

12. In a forming press including a frame, a vertically reciprocal forming member, a die bed positioned below said forming member, a drive shaft rotatably mounted in said frame, said drive shaft having a crank thereon, a connecting rod actuated by said crank to impart a forming force to said forming member, a bearing member rotatably mounted to said crank, said connecting rod including means defining a guide for said bearing means for movement within said connecting rod so that upon rotation of said crank said bearing means moves within said guide means and imparts motion of said crank to said connecting rod, a lifting cam carried by said drive shaft, and a cam follower carried by said connecting rod and adapted to be engaged by said cam to lift said connecting rod and said forming member.

13. The press of claim 12 wherein said forming member is a ram carrying a plurality of aligned plungers and two of said connecting rods are pivotally connected to said ram.

14. The press of claim .12 wherein said bearing member is linearly movable in said guides, said guide means including a bearing surface adapted to be engaged by said bearing member.

15. The press of claim 12 wherein a rectangular shaped opening is defined in the upper end of said connecting rod, said opening being defined by parallel guides, a bottom bearing surface and an upper wall, said bearing member being movable linearly on said parallel guides.

References Cited UNITED STATES PATENTS 276,292 4/ 1883" Seymour 74-571 460,642 10/ 1891 Kitson 74-571 924,307 6/ 1909 Bauroth 74-571 1,258,020 3/1918 Klocke 74-571 1,631,466 6/1927 Buifardi 74--57l 1,868,498 7/1932 Gruman 74-571 1,977,549 10/ 1934 Glasner -292 3,094,091 6/ 1963 Peccerill 100-292 3,199,358 8/1965 Bradlee 74-53 3,358,591 12/ 1967 Bradlee 100-257 357,294 2/ 1887 Webster 29-24354 976,726 8/ 1905 Horton 72-316 2,371,3 1 5 3/1945 Rhodes 83-635 CHARLES W. LANHAM, Primary Examiner G. P. CROSBY, Assistant Examiner US. Cl. X.R. 72-452 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3 605 479 Dated September 20 1971 Charles Robert Bradlee Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6, list of References Cited, line 66, "976,726" should read 796,726

Signed and sealed this 12th day of September 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR.

ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents RM F'O-1050 [10-69) USCOMM-DC 60376-5 59 9 U S, GOVERNHENY PRINTING OFFICE II O-lI-SSG,

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