US3762209A

US3762209A - Crimping apparatus

Info

Publication number: US3762209A
Application number: US00251231A
Authority: US
Inventors: L Herndon; C Pearson
Original assignee: Dayco Corp
Current assignee: Dayco Products LLC; United States Steel Corp
Priority date: 1972-05-08
Filing date: 1972-05-08
Publication date: 1973-10-02
Anticipated expiration: 1990-10-02

Abstract

A crimping apparatus is provided comprising a die head having a central longitudinal axis and a plurality of spaced slots therein each having an associated die finger received therewithin with each die finger having a workpiece-engaging surface and an outside cam surface. The apparatus includes a simple device independently supporting each finger within its slot for movement transverse the longitudinal axis and has a die plate which has a cooperating cam surface which is adapted to engage the outside cam surfaces so that a workpiece to be crimped is received adjacent the workpiece-engaging surfaces and upon relatively moving the die head and die plate together the cam surfaces engage the cooperating cam surface to thereby urge the die fingers radially inwardly causing the workpiece-engaging surfaces to crimp the workpiece. The die head construction is such that it can receive workpieces having bent end portions to enable swaging or crimping such end portions in position.

Description

United States Patent [1 1 Herndon et al.

[ 1 Oct. 2, 1973 CRIMPING APPARATUS [73] Assign cc: Dayco Corporation, Dayton, Ohio [22] Fild: May 8, 1972 [2]] Appl. No.: 251,231

[52] U.S. C1 72/402, 72/465, 29/237 [51] Int. Cl 821d 41/00 [58] Field of Search 72/402, 465; 29/237, 29/508, 517, 282

[56] References Cited UNITED STATES PATENTS 2,23l,278 2/1941 Miller 72/402 3,568,495 3/1971 Duffield... 72/402 3,096,876 7/1963 Scudieri... 72/402 3,579,794 5/1971 Powell 29/237 3,461,712 8/1969 Henkel et al. 72/402 1,867,625 7/1932 Huestis v 72/402 3,335,594 8/1967 Peterrnan et al 29/508 Primary Examiner-Charles W. Lanham Assistant ExaminerM. .l. Keenan At10rneyReuben Wolk [57] ABSTRACT A crimping apparatus is provided comprising a die head having a central longitudinal axis and a plurality of spaced slots therein each having an associated die finger received therewithin with each die finger having a workpiece-engaging surface and an outside cam surface. The apparatus includes a simple device independently supporting each finger within its slot for movement transverse the longitudinal axis and has a die plate which has a cooperating cam surface which is adapted to engage the outside cam surfaces so that a workpiece to be crimped is received adjacent the workpiececngaging surfaces and upon relatively moving the die head and die plate together the cam surfaces engage the cooperating cam surface to thereby urge the die fingers radially inwardly causing the workpiece-engaging surfaces to crimp the workpiece. The die head construction is such that it can receive workpieces having bent end portions to enable swaging or crimping such end portions in position.

15 Claims, 13 Drawing Figures PATENTEDBBT 2 3.762.209

SHEET 1 0F 2 PATENTEU 'Z H 3.762.209

SHEET 20F 2 33 FIG, 11

CRIMPING APPARATUS BACKGROUND OF THE INVENTION There are numerous swaging or crimping machines in current use which are used to swage or crimp various workpieces. For example, such machines are used to crimp various fittings and/or connecting devices on pipes, hoses, conduits, cables, wire ropes, etc. Most of these machines are only capable of crimping a so-called straight fitting which has its longitudinal axis arranged coaxially with a longitudinal axis of a member on which such fitting is to be crimped whereby such machines are not capable of crimping fittings having end portions which are bent through angular increments. In addition, practically all of these previous machines are either very complicated and expensive to fabricate and maintain in operation or use crimping dies which are difficult to install and replace during routine machine operation.

SUMMARY This invention provides a swaging or crimping apparatus of simple and economical construction which is particularly adapted for crimping straight as well as bent devices or fitting portions against associated portions or components of a workpiece. The apparatus comprises a substantially tubular die head having a portion which is readily removed and reinstalled to enable crimping bent fittings. The die head has a plurality of spaced slots therein which are arranged concentrically around a central longitudinal axis and has a plurality of die fingers corresponding in number to the number of slots with each finger having a workpiece-engaging surface and an outside cam surface and being received within an associated slot with the workpiece-engaging surfaces defining a substantially circular outline. Simple and easily installed and removed supporting means is provided for supporting each finger within its slot for movement transverse the longitudinal axis and the apparatus includes a die plate which has a cooperating cam surface which is adapted to engage the outside cam surfaces of the die fingers. The apparatus is adapted to receive a workpiece to be crimped within the circular peripheral outline defined by the workpiece-engaging surfaces and upon relatively moving the die head and die plate together the cam surfaces engage the cooperating cam surface causing movement of the die fingers toward the axis and causing the workpiece-engaging surfaces to engage and crimp the workpiece.

Other details, uses, and advantages of this invention will be readily apparent from the exemplary embodiments thereof presented in the following specification, claims, and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings show a present preferred embodiment of this invention, in which FIG. 1 is a side elevation with parts broken away illustrating one exemplary embodiment of the apparatus of this invention;

FIG. 2 is a view taken essentially on the line 2-2 of FIG. 1;

FIG. 3 is a view taken essentially on the line 3--3 of FIG. 1;

FIG. 4 is a view taken essentially on the line 44 of FIG. 2;

FIG. 5 is an exploded perspective view illustrating a typical die finger arranged above an associated slot provided in a removable portion of a die head comprising such apparatus and also illustrating an independent resilient supporting means used to support such die finger in its slot;

FIG. 6 is a view illustrating a fragmentary portion of a workpiece comprised of a straight hose portion and an end fitting portion having a bent configuration which is to be attached by crimping to the straight hose portion;

FIG. 7 is a view with parts in cross section and parts broken away illustrating the forward portion of a die head and an associated die plate comprising the apparatus of FIG. 1 prior to removing a removable portion of the die head to enable receipt of the workpiece of FIG. 6;

FIG. 8 is a view similar to FIG. 7 illustrating the removable portion of the die head removed to enable receipt of the workpiece of FIG. 6;

FIG. 9 is a view similar to FIG. 8 showing the workpiece of FIG. 6 installed in position with the removable portion of the head assembly still removed;

FIG. 10 is a view similar to FIG. 9 illustrating the removable portion of a head assembly installed in position around the workpiece of FIG. 6;

FIG. 11 illustrates the die head and the die plate of the apparatus of FIG. 1 in operative association with the workpiece being crimped therebetween;

FIG. 12 is a view similar to FIG. 9 illustrating the die head moved out of operative association with the die plate with the removable portion of the die head removed to enable removal of the now crimped workpiece; and

FIG. 13 is a view similar to FIG. 6 illustrating the workpiece with its bent fitting portion crimped firmly to its hose portion to define a completed workpiece.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS Reference is now made to FIG. 1 of the drawings which illustrates one exemplary embodiment of a swaging or crimping machine or apparatus of this invention which is designated generally by the reference numeral 20. The apparatus 20 comprises a base 21 having a sutiable supporting structure including a vertical support 23 suitably fixed on such base and another vertical support 24 also suitably fixed to the base 21 and arranged in parallel spaced relation from the support 23. The

supports

23 and 24 are held together as a structural unit by a plurality of horizontal rods 25. The apparatus 20 also comprises a die head 26 which is supported for operating movements by suitable means, to be subsequently described, and such die head operatively associates with a die plate 27 supported by the vertical support 24 to enable crimping of an associated workpiece through cooperation of the die head 26 and die plate 27 The die head 26 is a substantially tubular die head and has a plurality of spaced slots each designated by the reference numeral 30 provided therein, see FIGS. 1-3. The slots are arranged in equally angularly spaced relation about the periphery of the tubular die head 26 and circumferentially around a central horizontally arranged longitudinal axis through the die head 26 which coincides with the central axis of the die plate 27 and this common axis is designated by the reference letter A.

The die head 26 has a plurality of die fingers 31 corresponding in number to the number of slots 30 and each finger has an inside workpiece-engaging surface 32 and an outside cam surface 33 adjoined at the forward end thereof by a lead-in surface 34. Each finger 31 is received within an associated slot 30 and is provided with suitable supporting means designated generally by the reference numeral 35 supporting each finger 31 within its slot for movement transverse the longitudinal axis A. The manner in which supporting means 35 provides a supporting function will be described in detail subsequently.

The die plate 27 has a cooperating cam surface which in this example is a substantially frustoconical surface 36. The surface 36 is adapted to engage the outside cam surfaces 33 of the die fingers 31, as well as the leadin surfaces 34. The apparatus is particularly adapted to receive a workpiece, such as an assembly 37, for example, which is illustrated in FIG. 6 of the drawings and is comprised of a substantially rectilinear or straight hose portion 40 and an end device or portion in the form of a bent fitting 41 having an integral straight sleeve 42 and an angled or bent end portion which in this illustration is substantially L-shaped. The assembly or workpiece 37 is crimped in the apparatus 20 by crimping sleeve 42 firmly against the hose portion 40 to define a completed assembly and a unitary construction which is also designated by the reference numeral 37 and is illustrated in FIG. 13 of the drawings.

The die head 26 has a rear portion 44 which is provided with a cutout 45, see FIG. 3, in the top portion thereof which is particularly adapted to receive a workpiece having an angled or bent fitting portion such as the L-shaped portion 43 of fitting 41 therein. To enable the uncrimped workpiece 37 having a substantial length of hose portion 40 provided as part thereof to be placed through the forward end, indicated at 46 in FIG. 1, of the apparatus 20 the die head 26 has a readily removable portion which is designated by the reference numeral 47. The portion 47 may be removed or moved out of position either manually or utilizing any suitable automatic means, and in the manner illustrated in FIG. 8 of the drawings, for example. The L-shaped portion 43 of fitting 41 may then be placed in position through the forward end 46 of the apparatus 20, see FIG. 9, whereupon the removable portion 47 of the die head 26 is returned and suitably fastened in position to enable crimping of the workpiece 37 and in particular the sleeve 42 thereof.

The crimping action is provided by relatively moving the die head 26 and die plate 27 toward each other and because in this example such die plate is supported at a fixed position the die head 26 is adapted to be moved in a reciprocating rectilinear path. The die head 26 may be moved by suitable moving means such as a fluidoperated cylinder 50 which is operatively connected to the rear portion 44 of the die head by a pin 51. To assure that the die head 26 is moved horizontally along its longitudinal axis A the apparatus 20 has a pair of spaced horizontal ways 52 each suitably attached to an associated rod by a pair of fastening clamp assemblies 53. A pair of slide units 54 are provided and fastened at fixed positions on opposite sides of the rear portion 44 of the die head 26 and each slide unit 54 has a lower portion 55 which engages an associated horizontal way 52. To assure the die head 26 moves in the required precision manner each unit 54 may be provided with a projection on its lower position which extends into a cooperating slot in its horizontal way 52 whereby each unit 54 (and hence head 26) is guided for precision rectilinear movements parallel to the axis A.

The die head 26 is moved by actuating the cylinder 50 causing it to extend a piston rod portion 56 thereof outwardly moving the rear portion 44 of the die head and the slide units 54 on horizontal ways 52. The cylinder 50 may be actuated utilizing a suitable electrically operated selector valve assembly 57 which may be suitably operated either manually or automatically.

To extend piston rod 56 and move die head 26 into operative association with die plate 27 the valve assembly 53 diverts the flow of a fluid under regulated pressure through a line 57A and a fitting 58 causing such fluid to act against the rear surface of a piston 59 which is housed within the cylinder 50 and is connected to the piston rod 56. To retract the piston rod 56 and die head 26 fluid is supplied through a line 578 and a fitting 61 to the forward face of the piston 59 causing retraction of die head 26 to the position illustrated in FIG. I of the drawings.

The apparatus 20 may have suitable control means to enable either manual operation, automatic operation, or both of the die head 26. Such control means may include a suitable position control switch which energizes valve assembly 57 and shuts off fluid flow through fitting 58 to the rear of the piston 59 once the die head 26 has moved the required distance into operative association with the die plate 27. A portion of this same switch or another switch may also comprise the control means and may be used to reverse fluid flow through assembly 57 and hence provide flow through fitting 61 to the forward surface of the piston 59 to retract the die head 20 to the position of FIG. 1, and once the head reaches the position illustrated, fluid flow through fitting 61 is shut off by actuating assembly 57 to a central neutral position.

As previously indicated the apparatus 20 includes supporting means 35 detachably fastening each of the fingers 31 to the die head 26 and in this example such supporting means is in the form of a plurality of mechanical spring devices and for simplicity, each spring device is also designated by the reference numeral 35. Each spring device, see FIGS. 3 and 4, has one end portion attached to an associated finger 31 and its opposite end portion detachably fastened to the die head 26 in a manner now to be described. In particular, each spring device 35 has a substantially U-shaped portion comprised of a bight 64 and a pair of outwardly extending arms 65 terminating in axially aligned inwardly extending portions 66. The bight 64 is in the form of a coiled spring comprised of a pair of spaced

coiled portions

64A and 64B interconnected by a single thickness portion 64C which is used to detachably fasten the inner portion of the spring device 35 to the die head 26 and for this purpose a metal screw 67 extends through a loop-like center of portion 64C and is threadedly received within a cooperating threaded opening in the die head 26. Each spring device 35 may be made of any suitable material, however, it is preferably made of a single piece of spring material which may have a suitable cross-sectional configuration and in this example has a circular cross-sectional configuration.

Each die finger 31 has opposed parallel surfaces 68 and a pair of coaxial bores 69 each extending inwardly from an associated surface 68. Each spring device 35 supports an associated finger 31 by inserting portions 66 of such device within associated bores 69 and with portion 64C fastened by metal screw 67 against the die head 26 whereupon the coiled spring portions of device 35 are made such that'device 35 resiliently holds its arms 65 outwardly away from the axis A. Thus, it is seen that each die finger 31 is resiliently held or suspended by, a spring device 35.

It is a simple matter to install each die finger 31 initially on the die head 26 or replace a worn die finger. This may be achieved simply by lifting a finger 31 radially outwardly in a direction indicated by a typical arrow 70 in FIG. 2 whereupon the arms 65 of device are spread apart and portions 66 removed from within bores 69. A new die finger 31 may then be placed within the vacant slot 30 and portions 66 snapped into position in associated bores 69 of the new die finger. Of course, it will also be appreciated that each spring device 35 and its die finger 31 may also be removed simply by unthreading or unfastening the threaded screw 67. Thus, it will be appreciated that each die finger 31 may be installed initially or replaced without disassembly of other components comprising apparatus 20.

The removable portion 47 of the die head 26 may comprise any portion thereof and as seen in FIGS. 2 and 8 such portion comprises substantially one half of the tubular die head 26 and each half is provided with a plurality of four slots 30 each carrying an associated die finger 31. Each slot 30, see FIGS. 4 and 5, may have a substantially rectangular outline and is defined by a plurality of four cooperating

surfaces

71, 72, 73, and 74. In this example, surface 74 of each slot is the rear surface and defines a bearing surface which is arranged in a plane substantially perpendicular to the longitudinal axis A. Upon relatively moving the die head 26 and die plate 27 into operative association the rear bearing surface 74 supports its finger 31 in the axial direction while allowing sliding movement of the finger radially inwardly and the surfaces 7l-73 serve as precision guide surfaces which assure workpiece engaging surfaces 32 will be brought into precise engagement with the workpiece 37.

As will be apparent from FIG. 2 of the drawings the fingers 31 are arranged in the tubular die head 26 so that the workpiece engaging surfaces 32 are arranged in a circular pattern indicated by dot-dash lines in FIG. 2 and having a particular diameter 76. Upon moving the die head 26 into operative association with the fixed die plate 27 the die fingers are moved radially inwardly by the inclined cam surface 33 engaging the frustoconical cam surface 36 to thereby define a smaller circular pattern indicated by dotted lines and having a smaller diameter 77 whereby the workpiece engaging surfaces 32 crimp portion 42 of the workpiece 37.

Having described the detailed construction of the various cooperating components comprising the apparatus 20, the presentation will now proceed while referring to FIGS. 6-13 of the drawings to facilitate an understanding of the manner in which exemplary workpiece 37 may be.crimped notwithstanding the fact such workpiece has a bent or L-shaped fitting portion 43.

Initially the cylinder 50 is suitably actuated causing retraction of the die head 26 to the position illustrated at in FIG. 7 of the drawings. The removable portion 47 of the die head 26 is then removed utilizing any suitable means as illustrated at 81 in FIG. 8 whereupon the uncrimped workpiece 37 is installed in position as illustrated at 82 in FIG. 9.

The removable portion 47 of the die head 26 is then restored to its normal operating position and suitably fixed in position as illustrated at 83 in FIG. 10. The cylinder 50 is then actuated causing movement of the die head 26 in a rectilinear horizontal path as indicated by the arrow 84 in FIG. 11 and into operative association with the die plate 27 to the position illustrated at 85. During this horizontal movement of the die head 26 the cam surfaces 33 engage the frustoconical surface 36 causing the die fingers 31 to override the tendency of their associated supporting devices 35 to hold such fingers resiliently outwardly and causing the workpieceengaging surfaces 32 of the fingers 31 to engage the sleeve portion 42 of workpiece 37 and swage or crimp such sleeve and hence fitting 41 onto hose portion 40.

Once this crimping action has been achieved the cylinder 50 is again actuated to retract the die head to a position essentially similar to the position illustrated in FIG. 10 whereupon the removable portion 47 of the die head is lifted away as illustrated at 86 in FIG. 12. The workpiece 37 with its fitting portion 41 now crimped into position may be removed and such completed workpiece is illustrated in FIG. 13. The removable portion 47 of the die head 26 is held away from the remainder of such die head which is essentially the position illustrated in FIG. 8 whereupon another workpiece to be crimped may be introduced into the apparatus 20 and the operation repeated essentially as described above.

In this disclosure of the invention, the apparatus 20 has been illustrated and described as crimping a workpiece 37 which comprises a straight hose portion or construction which has a fitting provided with a bent terminal end 43; however, it is to be understood that the apparatus 20 may be used to crimp straight, enlarged, or contouredfitting portions or devices on either flexible or rigid pipes, conduits, rods, wire ropes, etc.

In addition, the apparatus 20 may be suitably modified to swage or otherwise work metal workpieces and in each instance the unique construction of the die head with its removable portion as well as its readily removable die fingers enables operation with optimum efficiency.

While present exemplary embodiments of this invention, and methods of practicing the same, have been'illustrated and described, it will be recognized that this invention may be otherwise variously embodied and practiced within the scope of the following claims.

What is claimed is:

1. A crimping apparatus comprising, a die head having a plurality of spaced slots therein and a central longitudinal axis; a plurality of die fingers corresponding in number to said plurality of slots, with each finger having a workpiece-engaging surface and an outside cam surface and being received within an associated slot; means supporting each finger within its slot for movement transverse said longitudinal axis and detachably fastening each of said fingers to said die head, said means comprising a plurality of mechanical spring devices each having one end portion attached to an associated finger and its opposite end portion detachably fastened to said head and normally resiliently holding said fingers away from said central axis, each finger having opposed parallel surfaces and a pair of coaxial bores each extending inwardly from an associated surface, each device comprising a substantially U-shaped portion having a bight and a pair of outwardly extending arms terminating in aligned inwardly extending portions which are received in the bores of an associated finger, said bight comprising a coiled spring which resiliently holds its arms outwardly away from said axis and suspends the associated finger on its inwardly extending portions, and means detachably fastening said bight against said die head; and a die plate having a cooperating cam surface which is adapted to engage said outside cam surfaces; said apparatus being adapted to receive a workpiece to be crimped adjacent said workpieceengaging surfaces and upon relatively moving said die head and die plate together said cam surfaces engage said cooperating cam surface causing movement of said die fingers toward said axis and causing said workpieceengaging surfaces to engage and crimp said workpiece.

2. An apparatus as set forth in claim 1 in which said coiled spring has a pair of spaced coiled portions interconnected by a single thickness portion and said means detachably fastening comprises a metal screw threadedly fastened to said die head.

3. An apparatus as set forth in claim 1 in which said spring device is made of a single piece of spring material.

4. An apparatus as set forth in claim 1 in which said die head has a fixed portion and a removable portion, said portions having said slots provided therein and said supporting means comprises independent means detachably fastening each of said fingers to an associated portion of said die head, and upon temporarily removing said removable portion a workpiece having a bent end portion may be easily placed in position so that a portion thereof which is to be crimped is arranged adjacent said workpiece-engaging surfaces.

5. An apparatus as set forth in claim 4 in which said die head has a cutout provided therein rearwardly of said die fingers, said cutout being adapted to receive said bent end portion therethrough in an unobstructed manner.

6. An apparatus as set forth in claim 4 in which said head has a substantially tubular configuration and said spaced slots are provided therein at equally spaced angular increments.

7. An apparatus as set forth in claim 1 in which each of said cam surfaces comprises an inclined cam surface which is inclined at an acute angle relative to said axis and said cooperating cam surface comprises a substantially frustoconical surface.

8. An apparatus as set forth in claim 1 in which, said die head has a substantially tubular configuration and said spaced slots are provided therein at equally spaced angular increments with each of said cam surfaces comprising an inclined surface which is inclined at an acute angle relative to said axis, said cooperating cam surface comprises a frustoconical surface, said workpiece engaging surfaces are arranged in parallel relation and in a substantially circular pattern having a particular diameter, and said die head and die plate are relatively moved together by relative movement substantially parallel to said axis whereupon said die fingers are moved radially inwardly by the inclined cam surfaces engaging said frustoconical surface to thereby reduce the diameter of said circular pattern and bring said workpiece engaging surfaces against said workpiece to thereby crimp said workpiece.

9. An apparatus as set forth in claim 8 in which each of said slots in said die head is defined by a plurality of four cooperating surfaces arranged in a rectangular pattern with one of said surfaces being a rear bearing surface which is arranged in a plane which extends substantially perpendicular to said longitudinal axis, and upon relatively moving said die head and die plate together the rear bearing surface of each slot supports its finger against rearward movement parallel to said axis while the remaining surfaces of the slot guide its finger during radially inward movement thereof caused by said relative movement substantially parallel to said axis.

10. A crimping apparatus comprising a base; a substantially tubular die head having a plurality of spaced slots provided therein at equally spaced angular increments with said die head having a central horizontally arranged longitudinal axis, means supporting said die head on said base for horizontal movements along said axis; a plurality of die fingers corresponding in number to said plurality of slots with each finger having opposed parallel surfaces and a pair of coaxial bores each extending inwardly from an associated surface and having a workpiece-engaging surface and an outside cam surface and being received within an associated slot; a plurality of mechanical spring devices supporting each finger within its slot for movement toward and away from said longitudinal axis, said spring devices each having an end portion attached to an associated finger and normally resiliently holding said fingers away from said central axis, and having a bight and a'pair of outwardly extending arms terminating in aligned inwardly extending arm portions which are received in the bores of an associated finger, said bight comprising a coiled spring which resiliently holds its arms outwardly away from said axis and suspends the associated finger on its inwardly extending portions, and means fastening said bight against said die head; a die plate supported at a fixed position on said base and normally in spaced relation from the terminal end of said die head, said die plate having a cooperating cam surface which is adapted to engage said outside cam surfaces, said apparatus being adapted to receive a workpiece to be crimped adjacent said workpiece-engaging surfaces; and means moving said die head into operative association with said die plate causing said cam surfaces to engage said cooperating cam surface to thereby move said die fingers toward said axis and cause said workpiece-engaging surfaces to engage and crimp said workpiece.

11. An apparatus as set forth in claim 10 in which said moving means comprises a fluid-operated actuator.

12. An apparatus as set forth in claim 10 in which, said moving means comprises a fluid-operated cylinder having a piston rod extending therefrom which is operatively connected to said die head, said cylinder being adapted to provide reciprocating movements along said axis, and said supporting means comprising a pair of spaced horizontal ways carried by said base and arranged in parallel relation on opposite sides of said die head, and a pair of adjustable support units each slidably supported on an associated way.

therein, and upon temporarily removing said removable portion a workpiece having a bent end portion may be easily placed in position so that a portion thereof which is to be crimped is arranged adjacent said workpiece-engaging surfaces.

15. An apparatus as set forth in claim 14 in which said die head has a cutout provided therein rearwardly of said die fingers, said cutout being adapted to receive said bent end portion therethrough in an unobstructed manner

Claims

1. A crimping apparatus comprising, a die head having a plurality of spaced slots therein and a central longitudinal axis; a plurality of die fingers corresponding in number to said plurality of slots, with each finger having a workpiece-engaging surface and an outside cam surface and being received within an associated slot; means supporting each finger within its slot for movement transverse said longitudinal axis and detachably fastening each of said fingers to said die head, said means comprising a plurality of mechanical spring devices each having one end portion attached to an associated finger and its opposite end portion detachably fastened to said head and normally resiliently holding said fingers away from said central axis, each finger having opposed parallel surfaces and a pair of coaxial bores each extending inwardly from an associated surface, each device comprising a substantially U-shaped portion having a bight and a pair of outwardly extending arms terminating in aligned inwardly extending portions which are received in the bores of an associated finger, said bight comprising a coiled spring which resiliently holds its arms outwardly away from said axis and suspends the associated finger on its inwardly extending portions, and means detachably fastening said bight against said die head; and a die plate having a cooperating cam surface which is adapted to engage said outside cam surfaces; said apparatus being adapted to receive a workpiece to be crimped adjacent said workpiece-engaging surfaces and upon relatively moving said die head and die plate together said cam surfaces engage said cooperating cam surface causing movement of said die fingers toward said axis and causing said workpiece-engaging surfaces to engage and crimp said workpiece.

10. A crimping apparatus comprising a base; a substantially tubular die head having a plurality of spaced slots provided therein at equally spaced angular increments with said die head having a central horizontally arranged longitudinal axis, means supporting said die head on said base for horizontal movements along said axis; a plurality of die fingers corresponding in number to said plurality of slots with each finger having opposed parallel surfaces and a pair of coaxial bores each extending inwardly from an associated surface and having a workpiece-engaging surface and an outside cam surface and being received within an associated slot; a plurality of mechanical spring devices supporting each finger within its slot for movement toward and away from said longitudinal axis, said spring devices each having an end portion attached to an associated finger and normally resiliently holding said fingers away from said central axis, and having a bight and a pair of outwardly extending arms terminating in aligned inwardly extending arm portions which are received in the bores of an associated finger, said bight comprising a coiled spring which resiliently holds its arms outwardly away from said axis and suspends the associated finger on its inwardly extending portions, and means fastening said bight against said die head; a die plate supported at a fixed position on said base and normally in spaced relation from the terminal end of said die head, said die plate having a cooperating cam surface which is adapted to engage said outside cam surfaces, said apparatus being adapted to receive a workpiece to be crimped adjacent said workpiece-engaging surfaces; and means moving said die head into operative association with said die plate causing said cam surfaces to engage said cooperating cam surface to thereby move said die fingers toward said axis and cause said workpiece-engaging surfaces to engage and crimp saiD workpiece.

13. An apparatus as set forth in claim 12 in which said cylinder has a piston slidably supported therein and attached to said piston rod, and further comprising a selector valve assembly operatively connected to said cylinder and providing fluid under regulated pressure to opposite sides of said piston through associated conduits to provide reciprocating movements of said piston, piston rod, and die head.

14. An apparatus as set forth in claim 10 in which, said die head has a fixed portion and a removable portion with said portions having said slots provided therein, and upon temporarily removing said removable portion a workpiece having a bent end portion may be easily placed in position so that a portion thereof which is to be crimped is arranged adjacent said workpiece-engaging surfaces.

15. An apparatus as set forth in claim 14 in which said die head has a cutout provided therein rearwardly of said die fingers, said cutout being adapted to receive said bent end portion therethrough in an unobstructed manner.