WO2008034132A1

WO2008034132A1 - Compact crimping machine

Info

Publication number: WO2008034132A1
Application number: PCT/US2007/078648
Authority: WO
Inventors: Benjamin M. Trace; Mike Sweeney
Original assignee: Parker-Hannifin Corporation
Priority date: 2006-09-15
Filing date: 2007-09-17
Publication date: 2008-03-20

Abstract

An improved crimping apparatus (10) enables one or more advantages to be realized, including light weight, small size, low cost, use in various orientations such as on its side or upside down without deleterious effects to functionality, and accommodation of a larger variety of crimp fittings such as long drop bent tubes, etc. The crimping apparatus (10) in a preferred embodiment employs an annular piston (44) and in particular an annular piston that surrounds a central passage (24) in the base (12) through which a fitting and/or hose can be inserted into the crimping apparatus (10) by a die set (84) driven by actuation of the piston (44).

Description

COMPACT CRIMPING MACHINE

Related Application

This application claims the benefit of U.S. Provisional Application No. 60/825,740 filed September 15, 2006, which is hereby incorporated herein by reference.

Field of the Invention

The present invention relates to crimping machines and methods of operating crimping machines.

Background of the Invention

In prior art crimping machines of the type disclosed in U.S. Patent No. 4,309,892, hose assemblies are formed by forcing a circular array of die segments into a tapered bowl by means of a hydraulic actuator. A pusher is affixed to the operating end of the actuator and is designed with an opening therein to allow placement of hose ends (fittings) in the crimping machine. A pusher plate is positioned over the die segments and is contacted by the pusher to transmit force to all of the die segments simultaneously, while also being used as a device to limit the stroke of the actuator and thus the final crimp diameter.

Summary of the Invention

The present invention provides an improved crimping apparatus that enables one or more advantages to be realized, including light weight, small size, low cost, use in various orientations such as on its side or upside down without deleterious effects to functionality, and accommodation of a larger variety of crimp fittings such as long drop bent tubes, etc. The crimping apparatus in a preferred embodiment employs an annular piston and in particular an annular piston that surrounds a central passage in the base through which a fitting and/or hose can be inserted into the crimping apparatus and then crimped together by a die set driven by actuation of the piston. More particularly, an apparatus for crimping a fitting onto a hose, comprises a base including an annular piston chamber that surrounds an axially extending passage in the base through which at least one of the fitting or hose can be inserted into the base for crimping of the fitting to the hose; a crimp bowl having a central opening for receiving a plurality of die segments, the central opening being surrounded by a tapered surface that can coact with correspondingly tapered surfaces of the die segments for urging the die segments radially inwardly when the crimp bowl is urged axially toward a crimp ring; and an annular piston movable in the piston chamber for urging the crimp bowl toward the crimp ring.

In a preferred embodiment, the crimp ring can be separated from the base to allow for assembly of the die segments in the crimp bowl. Alternatively or additionally, the crimp ring may be coupled to the base by a quick-connect device. Alternatively or additionally, the quick-connect device may include at least one key slot in one of the base or crimp ring and at least one key in the other of the base or crimp ring that engages in the key slot to hold the crimp ring to the base against relative axial movement. Alternatively or additionally, the key slot may have two axially spaced apart catch surfaces for engaging the key so that the crimp ring can be held to the base at either one of two axially spaced positions. Alternatively or additionally, the crimp ring may have a tubular skirt that telescopes over an end of the base and includes either one of the key or key slot.

Alternatively or additionally, the crimp ring may have an abutment surface for engaging axial ends of the die segments to restrict movement thereof relative to the crimp ring, and a stop may be provided to limit the extent of movement of the crimp bowl toward the abutment surface. Alternatively or additionally, the stop may be formed by a stop ring interposed between the crimp ring and crimp bowl. Alternatively or additionally, the stop ring may be replaceable by at least one other stop ring having a different axial length to vary the extent to which the crimp bowl can be moved toward the abutment surface. Alternatively or additionally, the stop may be disposed at an axial end of a tubular guide, and the crimp bowl may have a nose portion that is telescopically movable in the tubular guide and that terminates at a radially protruding shoulder operable to engage the stop to limit the extent of movement of the crimp bowl toward the abutment surface.

Alternatively or additionally, a resilient member may be used to resiliently bias the piston away from the crimp ring, such that upon removal of fluid pressure from the piston chamber the piston will be urged by the resilient member away from the crimp ring.

Alternatively or additionally, the crimp bowl may be formed separately from the piston. Alternatively or additionally, the crimp bowl may be formed separately from the piston and fixedly attached to the piston for common movement with the piston.

Alternatively or additionally, the apparatus may include an annular die separator operable to prevent misalignment of the die segments when assembled in the crimp bowl, which die separator may be resiliently biased toward the crimp bowl such that the die separator will move with the crimp bowl during a least a portion of its movement toward the crimp ring.

Alternatively or additionally, the base may be provided with a port for supplying fluid pressure to the piston chamber for urging the piston toward the crimp ring.

Alternatively or additionally, the crimp ring may be assembled to the base in a plug-bayonet fashion. Alternatively or additionally, the crimp ring may have a plurality of circumferentially spaced tabs extending radially therefrom, and the base may have a plurality of circumferentially spaced key slots for receiving respective tabs, the tabs being insertable axially into respective key slots and then rotated relative to the key slots into circumferentially extending slot portions for restraining the tabs against axial movement away from the base.

Alternatively or additionally, the crimp ring may be assembled to the base in a socket-bayonet fashion. Alternatively or additionally, the crimp ring may be replaceable with different crimp rings and/or interchangeable axial spacers may be provided to vary the movement stroke of the die segments. Alternatively or additionally, the crimping apparatus may be used in combination with a stand, the base and stand having mating ports for supplying fluid pressure from the stand to the piston chamber in the base. Alternatively or additionally, the stand may have a cradle for receiving the base of the apparatus. Alternatively or additionally, the base may include a hydraulic fluid reservoir and a pump for supplying pressurized fluid to the piston chamber in the base.

According to another aspect of the invention, a method for crimping a fitting onto a hose, comprises installing a plurality of die segments in a central opening of a crimp bowl of a crimping apparatus, which opening is surrounded by a tapered surface that can coact with correspondingly tapered surfaces of the die segments for urging the die segments radially inwardly when the crimp bowl is urged axially toward a crimp ring; assembling a crimp ring to the base; inserting a fitting and a hose into a region of the apparatus that is surrounded by the die segments, with at least one of the fitting or hose being inserted through an axially extending passage in a base that includes an annular piston chamber surrounding the axially extending passage; and moving an annular piston in the piston chamber to urge the crimp bowl toward the crimp ring and thereby cause the die segments to move radially inwardly to crimp the fitting to the hose. Alternatively or additionally, the method may comprise selecting from different crimp rings and/or interchangeable axial spacers to vary the movement stroke of the die segments.

Alternatively or additionally, a quick-connect feature may be used to assemble the crimp ring to the base. Further features of the invention will become apparent from the following detailed description when considered in conjunction with the drawings.

Brief Description of Drawings

In the annexed drawings: Fig. 1 is a perspective view of an exemplary crimping machine according to the invention;

Fig. 2 is a cross-sectional view of the crimping machine of Fig. 1 ; Fig. 3 is a perspective view of the crimping machine with the crimp ring removed to show part of a quick-connect device used to connect the crimp ring to a base of the crimping machine;

Fig. 4 is a perspective view showing the crimping machine "plugged" into a stand;

Fig. 5 is a perspective view of the crimping machine and stand of Fig. 4, but looking in an opposite direction;

Fig. 6 is a perspective view of another exemplary embodiment of crimping machine according to the invention; Fig. 7 is a cross-sectional view of the crimping machine of Fig. 6, showing a set of die segments assembled therein between a base and crimp ring of the machine;

Fig. 8 is a plan view of the base of the crimping machine of Fig. 6; and

Fig. 9 is a plan view of the crimp ring of the crimping machine of Fig. 6.

Detailed Description

Referring now to the drawings in detail and initially to Fig. 1 , an exemplary crimping machine according to the invention is indicated generally by reference numeral 10. The crimping machine comprises a base 12 and a crimp ring 14. The crimp ring 14 may be equipped with a carrying device to facilitate portability. In the illustrated embodiment, a swing handle 16 is attached to the crimp ring 14. The crimp ring may have on its top side a recess 18 for stowage of the handle flush with the top surface of the crimp ring when the handle is not in use. This will avoid interference of the handle with fittings and/or hoses that are being crimped together in the crimping machine. Other carrying devices can be provided on the crimp ring or base, as desired.

Referring now to Fig. 2, the crimp ring 14 has a main ring portion 20 from which an annular skirt 22 depends. The main ring portion 20 has a central opening 24 through which a fitting and/or hose may be inserted. The annular skirt preferably has an inner diameter surface that will closely telescope over an upper cylindrical portion of the base as shown. As a result, the crimp ring essentially forms a cover for the base. The crimp ring 14 may be attached to the base 12 in any suitable manner. For example, the crimp ring and base may be provided with cooperating threaded portions whereby the crimp ring may be screwed onto the base. For easier and quicker attachment, a suitable quick-connect device may be used. The illustrated exemplary quick-connect device 26 comprises one or more keys 28 and corresponding key slots 30. As shown, the keys may be in the form of pins fixed to or formed integrally with the crimp ring 14, and the key slots 30 may be provided in the tubular, preferably cylindrical, wall 32 of the base 12. In the illustrated embodiment, each key slot 30 has an axially extending portion 34 opening to a top edge surface 36 of the base and a laterally (circumferentially) extending catch portion 38 for receiving a corresponding pin 28. As will be appreciated, the inwardly protruding pins 28 on the depending skirt of the crimp ring may be aligned with and axially inserted into the axial portions of respective key slots until the pins align with the catch portion of the key slots, after which the crimp ring may be rotated to move the pins into engagement in the catch portions of the key slots for holding the crimp ring to the base against axial separation. The crimp ring may be easily disassembled from the base in a reverse manner.

As best seen in Fig. 3, the key slot 30 may be provided with at least one additional laterally (circumferentially) extending catch portion 40 axially spaced from the catch portion 38 whereby the crimp ring may be attached to the base at any one of multiple axially offset positions. The purpose for this will become more apparent from the following description. It is noted for now that this enables the crimping stroke of the machine to be varied so that, for example, a single die set may be used to crimp different size fittings (or different size ranges of fittings). As shown, the catch portions can extend in opposite directions from the common axial portion such that the crimp ring can be turned in one direction to engage the pin in one of the catch portions and in the opposite direction to engage the crimp ring in the other catch portion. A further variation would be to provide two sets of key slots for the respective axial attachment positions of the crimp ring. Reverting back to Fig. 2, the base 12 includes an annular piston chamber 42 in which an annular piston 44 is disposed for reciprocal axial movement. The annular piston preferably is provided with suitable seals 46, 48 and 50 for sealing to the walls of the piston chamber. The annular piston 44 defines with the piston chamber 42 a fluid pressure chamber 52 that communicates with a port 54 in a wall of the base 12 to which a supply of pressurized, preferably hydraulic, fluid can be connected. In the illustrated embodiment, the port 54 has connected thereto a fitting 56 that enables easy connection to a mating fitting in a stand 58, as will be described below in greater detail in reference to Figs. 4 and 5. The fitting 56 may be surrounded by a protective shield 60.

As will be appreciated, pressurized fluid can be supplied via port 54 to the fluid pressure chamber 52 to urge the annular piston 44 toward the crimp ring 14, while draining of fluid from the fluid pressure chamber will allow the annular piston to move away from the crimp ring, preferably with the aid of a return spring 62 or other suitable resilient member. As shown, the return spring 62 may be interposed between an end of the annular piston and a stop ring 64.

In the illustrated embodiment, the piston chamber 52 is formed between a tubular, preferably cylindrical, wall portion 32 of the base and a tubular, preferably cylindrical, insert 66 that forms part of the base. The insert 66 may be integral with the wall portion 32, but preferably is formed as a separate piece to facilitate assembly of the crimping machine 10. As shown, the tubular insert 66 is inserted through a bottom opening or bore 68 in a main body portion 70 of the base. The tubular insert has a radially outwardly protruding flange 72 that axially engages an axial shoulder surrounding the opening 68, and the flange can be trapped against the shoulder by a retainer clip 74 as shown. An annular seal 76 may be provided to seal the tubular insert to an inner diameter surface of the main body portion 70 of the base.

As seen in Fig. 2, the tubular insert 66, and also the annular piston chamber 42 and annular piston 44, surround an axially extending passage 78 in the base 12 through which at least one of the fitting and/or hose can be inserted into the base for crimping of the fitting to the hose. The axially extending passage 78 leads to a central opening 80 of a crimp bowl 82 that is configured to receive a plurality of die segments, two of which are illustrated in broken lines at 84 in Fig. 2. As will be appreciated, conventional die segments may be used in the crimping machine 10. Typically, the die segments are arranged in a circular array, and the die segments may connected together by suitable means that allow the die segments to move toward and away from one another for assembly in the bowl and crimping a fitting to a hose.

The central opening 80 is surrounded by a tapered surface 86 of the crimp bowl 82 that can coact with correspondingly tapered surfaces of the die segments 84 for urging the die segments radially inwardly when the crimp bowl is urged axially toward a crimp ring 14 by the annular piston 44. As seen in Fig. 2, the crimp bowl is positioned to be axially engaged by the piston for movement toward the crimp ring when pressurized fluid is supplied to the fluid pressure chamber 52. In the illustrated embodiment, the crimp bowl 82 is fixed to the annular piston 44 for common movement therewith. The crimp bowl may be formed integrally with the piston (as a unitary piece), but preferably it is formed as a separate piece since the crimp bowl is subjected to substantial radial loads. As shown, the crimp bowl may have a tubular end portion that fits in a socket at the end of the annular piston, and a retaining ring 88 is used to secure the crimp bowl to the annular piston.

When the crimp bowl 82 is urged toward the crimp ring 14 by the annular piston 44, the die segments 84 will be forcibly urged against an abutment surface 90 of the crimp ring. Consequently, further axial movement of the die segments will be prevented. The crimp bowl, however, will continue to move toward the crimp ring, this causing the die segments to be cammed radially inwardly toward a fitting inserted therebetween, thereby to crimp the fitting to a hose positioned interiorly of the portion of the fitting being crimped to the hose. In the illustrated embodiment and as is preferred, the crimp bowl 82 travels axially until it reaches the stop ring 64. The stop ring provides a positive stop for the crimp bowl. Thus, the fitting crimp diameter will be determined by the position of the crimp ring with respect to the base. As above mentioned, the key slots in the exterior of the cylinder and pins mounted in the crimp ring allow for two separate crimp diameters with the same crimp die set. This avoids the need for two separate sets of die rings as was needed in prior art designs where the amount of die closure governs the fitting/hose retention. That is, they rely on the piston to stop against a removable die ring and the base of the crimp bowl.

The stop ring 64 may also function as a guide for the crimp bowl 82. The leading end of the crimp bowl may telescope into the stop ring that closely surrounds the leading or nose end of the crimp bowl. Advance of the crimp bowl will continue until a radially protruding shoulder 94 thereon engages an axial stop surface 96 on the stop ring. Such engagement blocks any further advance of the crimp bowl toward the crimp ring. The position of the axial stop surface will be determined by which axial position the crimp ring is attached to the base.

In lieu of or in addition to providing two or more axially spaced apart attachment positions of the crimp ring 14, the stop ring 64 may be interchanged with a different stop ring that provides a different limit to the stroke of the crimp bowl 82. For example, stop rings of different axial lengths may be used to provide for crimping of different size fittings with the same die set.

As illustrated in Fig. 2, an annular die separator 98 may be provided. The die separator functions in a manner similar to that described in U.S. Patent No. 4,527,414, which is hereby incorporated herein by reference. That is, the die separator is operable to prevent misalignment of the die segments when assembled in the crimp bowl. As shown, the die separator has a crown shape to edge and is resiliently biased toward the crimp bowl such that the die separator will move with the crimp bowl during a least a portion of its movement toward the crimp ring. The die separator, however, will yield to the die segments as the die segments are being forced radially inwardly toward one another.

Although presumably already evident from the foregoing description, an exemplary operation of the crimping machine will now be described. Initially, the crimp ring 14 is rotated until the pins 28 align with longitudinal slots 34 so that the crimp ring can be axially removed from the base 12. A die set is then assembled in the crimp bowl with the typically flat surfaces thereof facing out (i.e. away from the crimp bowl). The crimp ring is then reassembled onto the base and turned either right or left to the desired radial slot 38, 40 to provide the desired crimp stroke depending on the size of the fitting.

Now a fitting can be assembled to a hose and inserted through the passage in the base. Alternatively, the fitting can be inserted through the opening 24 in the crimp ring and assembled to a hose that has been inserted through the passage in the base, or vice versa.

At this point, a pressure source can be activated to deliver pressurized fluid to the fluid pressure chamber 52. This will cause the crimp bowl 82 to advance to the stop ring 64. The taper in the crimp bowl closes the crimp die set around the fitting and exerts sufficient force to form the fitting onto the hose. The pressure source can then be deactivated to allow the spring to retract the crimp bowl and piston and release the assembled hose fitting and hose from the die set. The finished hose assembly can the be removed from the crimping machine. Referring now to Figs. 4 and 5, the crimping machine 10 is shown assembled to a stand 58. The stand may have a fitting 100, such as a socket, for mating with fitting 56 on the crimping machine. The fittings may be oriented such that the crimping machine may be simply "plugged" into the stand that may be provided with a cradle 102 for receiving the crimping machine. The cradle or other base structure 102 of the stand may house a reservoir for the pressure (hydraulic) fluid and a pump for supplying pressured fluid to the crimping machine. The stand further may be provided with suitable controls and/or control circuitry for controlling operation of the crimping machine.

The crimping machine of Figs. 1-3 uses a crimp ring 14 that is assembled to the base in a socket-bayonet fashion. In another embodiment of crimping machine according to the invention, the crimp ring may be assembled to the base in a plug-bayonet fashion, as is the case of the crimping machine 110 shown in Figs. 6-9.

Referring now to Figs. 6 and 7, the crimping machine 110 comprises a base 112 and a crimp ring 114. The base 112 may be equipped with a carrying device to facilitate portability. In the illustrated embodiment, the base is provided with one or more handles 116. Other carrying devices can be provided on the crimp ring or base, as desired.

The crimp ring 114 may be attached to the base 112 in any suitable manner. For example, the crimp ring and base may be provided with cooperating threaded portions whereby the crimp ring may be screwed onto the base. For easier and quicker attachment, a suitable quick-connect device may be used. The illustrated exemplary quick-connect device 126 comprises one or more keys 128 and corresponding key slots 130. As seen in Figs. 7 and 9, the keys are in the form of tabs or ears that project radially from a central portion of the crimp ring, preferably in the same plane as the crimp ring. As seen in Figs. 7 and 8, the key slots 130 are provided in the tubular, preferably cylindrical, wall 132 of the base 112. In the illustrated embodiment, each key slot 130 has an axially extending portion 134 opening to a top edge surface 136 of the base and a laterally (circumferentially) extending catch portion 138 for receiving a corresponding ear 128. As will be appreciated, the protruding ears 128 and slots are correspondingly (such as equally) circumferentially spaced apart so that the ears can be aligned with and axially inserted into the axial portions of respective key slots until the ears align with the catch portion of the key slots, after which the crimp ring may be rotated to move the ears into engagement in the catch portions of the key slots for holding the crimp ring to the base against axial separation. The catch portions of the slots may extend between the axial portions of the key slots and thus may be formed by an annular groove. The crimp ring may be easily disassembled from the base in a reverse manner. Reverting back to Fig. 7, the base 112 includes an annular piston chamber 142 in which an annular piston 144 is disposed for reciprocal axial movement. The annular piston preferably is provided with suitable seals (not shown) for sealing to the walls of the piston chamber.

The annular piston 144 defines with the piston chamber 142 a fluid pressure chamber 152 that may communicate with a port (not shown, but which may be like the above described port) in a wall of the base 112 to which a supply of pressurized, preferably hydraulic, fluid can be connected. As will be appreciated, pressurized fluid can be supplied to the fluid pressure chamber 152 to urge the annular piston 144 toward the crimp ring 114, while draining of fluid from the fluid pressure chamber will allow the annular piston to move away from the crimp ring. In the illustrated embodiment, the piston chamber 152 is formed between a tubular, preferably cylindrical, outer wall portion 132 of the base and a tubular, preferably cylindrical, inner wall portion 166 of the base. The inner wall portion 166 may be integral with the wall portion 132 as shown, or may be formed as a separate piece. As seen in Fig. 7, the inner tubular wall 166, and also the annular piston chamber 142 and annular piston 144, surround an axially extending passage 178 in the base 112 through which at least one of the fitting and/or hose can be inserted into the base for crimping of the fitting to the hose.

The axially extending passage 178 leads to a central opening 180 of a crimp bowl 182 that is configured to receive a plurality of die segments 184. As will be appreciated, conventional die segments may be used in the crimping machine 10. Typically, the die segments are arranged in a circular array, and the die segments may connected together by suitable means that allow the die segments to move toward and away from one another for assembly in the bowl and crimping a fitting to a hose.

The central opening 180 is surrounded by a tapered surface 186 of the crimp bowl 182 that can coact with correspondingly tapered surfaces of the die segments 184 for urging the die segments radially inwardly when the crimp bowl is urged axially toward a crimp ring 114 by the annular piston 144. The crimp bowl may be formed as a separate piece (as in the manner described above), or may be unitary with the annular piston 144 for common movement therewith.

When the crimp bowl 182 is urged toward the crimp ring 114 by the annular piston 144, the die segments 184 will be forcibly urged against an abutment surface 190 of the crimp ring. Consequently, further axial movement of the die segments will be prevented. The crimp bowl, however, will continue to move toward the crimp ring, this causing the die segments to be cammed radially inwardly toward a fitting inserted therebetween, thereby to crimp the fitting to a hose positioned interiorly of the portion of the fitting being crimped to the hose.

As illustrated, the crimp bowl 182 can travel axially until it reaches the crimp ring 114. The crimp ring in this case provides a positive stop for the crimp bowl. Thus, the fitting crimp diameter can be determined by the position of the crimp ring with respect to the base.

As will be appreciated, the crimp ring 114 may be interchanged with a different crimp ring having an abutment surface located at a different axial spacing relative to the base, thereby to provide a different limit to the stroke of the crimp bowl. Alternatively or additionally, different thickness spacers may be interposed between the crimp bowl and the crimp ring to provide for crimping of different size fittings with the same die set.

The crimping machine 110 may be used and operated in a manner similar to that described above in connection with the crimping machine 10, although the crimp ring is assembled to and disassembled from the base as described above.

Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a "means") used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.

Claims

1. An apparatus for crimping a fitting onto a hose, comprising a base including an annular piston chamber that surrounds an axially extending passage in the base through which at least one of the fitting or hose can be inserted into the base for crimping of the fitting to the hose; a crimp bowl having a central opening for receiving a plurality of die segments, the central opening being surrounded by a tapered surface that can coact with correspondingly tapered surfaces of the die segments for urging the die segments radially inwardly when the crimp bowl is urged axially toward a crimp ring; and an annular piston movable in the piston chamber for urging the crimp bowl toward the crimp ring.

2. An apparatus according to claim 1 , wherein the crimp ring can be separated from the base to allow for assembly of the die segments in the crimp bowl.

3. An apparatus according to claim 1 or claim 2, wherein the crimp ring is coupled to the base by a quick-connect device.

4. An apparatus according to claim 3, wherein the quick-connect device includes at least one key slot in one of the base or crimp ring and at least one key in the other of the base or crimp ring that engages in the key slot to hold the crimp ring to the base against relative axial movement.

5. An apparatus according to claim 4, wherein the key slot has two axially spaced apart catch surfaces for engaging the key so that the crimp ring can be held to the base at either one of two axially spaced positions.

6. An apparatus according to claim 4 or claim 5, wherein the crimp ring has a tubular skirt that telescopes over an end of the base and includes either one of the key or key slot.

7. An apparatus according to any preceding claim, wherein the crimp ring has an abutment surface for engaging axial ends of the die segments to restrict movement thereof relative to the crimp ring, and a stop is provided to limit the extent of movement of the crimp bowl toward the abutment surface.

8. An apparatus according to claim 7, wherein the stop is formed by a stop ring interposed between the crimp ring and crimp bowl.

9. An apparatus according to claim 8, wherein the stop ring is replaceable by at least one other stop ring having different axial length to vary the extent to which the crimp bowl can be moved toward the abutment surface.

10. An apparatus according to any one of claims 7-9, wherein the stop is disposed at an axial end of a tubular guide, and the crimp bowl has a nose portion that is telescopically movable in the tubular guide and that terminates at a radially protruding shoulder operable to engage the stop to limit the extent of movement of the crimp bowl toward the abutment surface.

11. An apparatus according to any preceding claim, comprising a resilient member for resiliently biasing the piston away from the crimp ring, such that upon removal of fluid pressure from the piston chamber the piston will be urged by the resilient member away from the crimp ring.

12. An apparatus according to any preceding claim, wherein the crimp bowl is formed separately from the piston.

13. An apparatus according to any preceding claim, wherein the crimp bowl is formed separately from the piston and is fixedly attached to the piston for common movement with the piston.

14. An apparatus according to any preceding claim, comprising an annular die separator operable to prevent misalignment of the die segments when assembled in the crimp bowl, which die separator is resiliently biased toward the crimp bowl such that the die separator will move with the crimp bowl during a least a portion of its movement toward the crimp ring.

15. An apparatus according to any preceding claim, wherein the base is provided with a port for supplying fluid pressure to the piston chamber for urging the piston toward the crimp ring.

16. An apparatus according to any preceding claim, wherein the crimp ring is assembled to the base in a plug-bayonet fashion.

17. An apparatus according to claim 16, wherein the crimp ring has a plurality of circumferentially spaced tabs extending radially therefrom, and the base has a plurality of circumferentially spaced key slots for receiving respective tabs, the tabs being insertable axially into respective key slots and then rotated relative to the key slots into circumferentially extending slot portions for restraining the tabs against axial movement away from the base.

18. An apparatus according to any one of claims 1-15, wherein the crimp ring is assembled to the base in a socket-bayonet fashion.

19. An apparatus according to any preceding claim, wherein the crimp ring is replaceable with different crimp rings or interchangeable axial spacers are provided to vary the movement stroke of the die segments.

20. An apparatus according to any preceding claim, in combination with a stand, the base and stand having mating ports for supplying fluid pressure from the stand to the piston chamber in the base.

21. A combination as set forth in claim 20, wherein the stand has a cradle for receiving the base of the apparatus.

22. A combination as set forth in claim 20 or claim 21 , wherein the base includes a hydraulic fluid reservoir and a pump for supplying pressurized fluid to the piston chamber in the base.

23. A method for crimping a fitting onto a hose, comprising installing a plurality of die segments in a central opening of a crimp bowl of a crimping apparatus, which opening is surrounded by a tapered surface that can coact with correspondingly tapered surfaces of the die segments for urging the die segments radially inwardly when the crimp bowl is urged axially toward a crimp ring; assembling a crimp ring to the base; inserting a fitting and a hose into a region of the apparatus that is surrounded by the die segments, with at least one of the fitting or hose being inserted through an axially extending passage in a base that includes an annular piston chamber surrounding the axially extending passage; and moving an annular piston in the piston chamber to urge the crimp bowl toward the crimp ring and thereby cause the die segments to move radially inwardly to crimp the fitting to the hose.

24. A method according to claim 23, comprising the step of selecting from different crimp rings or interchangeable axial spacers vary the movement stroke of the die segments.

25. A method according to claim 23 or 24, wherein a quick-connect feature is used to assemble the crimp ring to the base.