CLAIMS:

1. A stored energy coupling for connecting a pulling apparatus to a ham mer (86) and a pipe bursting head (43), characterized by a coupling housing (2) engaging the hammer (86) for selective striking by the hammer (86); a rod (64) having one end slidably disposed in one end of said coupling housing (2); and a rod plate (65) carried by said one end of said rod (64) and the opposite end of said rod (64) from said one end connected to the pulling apparatus, wherein said rod plate (65) and said rod (64) are slidably displaced in said coupling housing (2) responsive to striking of said coupling housing (2) by the hammer (86).

2. The stored energy coupling of claim 1 characterized in that said hammer (86) is disposed inside said coupling housing (2) and further characterized by a striker plate (85) fixed in said coupling housing (2) for striking by said hammer (86) and by at least one bias mechanism (67) provided on said rod (64) inside said coupling housing (2), said bias mechanism (67) interposed between said rod plate (65) and said one end of said coupling housing (2) for tensioning said rod (64) responsive to operation of the pulling apparatus and advancing said pipe bursting head (43) toward the pulling apparatus responsive to said striking of said striker plate (85) by the hammer (86), wherein said bias mechanism (67) may comprise a plurality of springs (68, 68a, 68b) disposed on said rod (64) in said coupling housing (2) between said rod plate (65) and said one end of said coupling housing (2).

3. The stored energy coupling of claim 1 characterized in that said pipe bursting (43) head is provided on said coupling housing (2) and the hammer (86) is disposed in said coupling housing (2) opposite said rod plate (65) and further characterized by a striker plate (85 ) fixedly disposed in said coupling housing (2) between the hammer (86) and said rod plate (65) for said selective striking by the hammer (86), wherein at least one spring (68, 68a, 68b) may be provided on said rod (64-) inside

said coupling housing (2), said at least one spring (68, 68a, 68b) interposed between said rod plate (65) and said one end of said coupling housing (2) for tensioning said rod (64) responsive to operation of the pulling apparatus and advancing said pipe bursting head (43) toward the pulling apparatus responsive to said selective striking by operation of the hammer (86); or characterized in that the hammer (86) is disposed in the opposite end of said coupling housing (2) from said one end and opposite said rod plate (65) and further characterized by a striker plate (85) fixed in said coupling housing (2) between said rod plate (65) and the hammer (86) for said selective striking by the hammer (86) and by at least one spring (68, 68a, 68b) provided on said rod (64) inside said coupling housing (2), said spring (68, 68a, 68b) interposed between said rod plate (65) and said one end of said coupling housing (2) for tensioning said rod

(64) responsive to operation of the pulling apparatus and advancing said pipe bursting head (43) toward the pulling apparatus responsive to said operation of the hammer (86), wherein a cable (40) may be provided having one end connected to the opposite end of said rod (64) from said one end and the opposite end of said cable (40) attached to the pulling apparatus, wherein said pipe bursting head (43) may be provided on said coupling housing (2) forwardly of the hammer (86) or characterized ϊn that the hammer (86) is disposed in said coupling housing (2) opposite said rod plate (65) and said pipe bursting head (43) is located on said coupling housing (2) forwardly of the hammer (86) and further characterized by a striker plate (85) fixed in said coupling housing (2) between said rod plate

(65) and the hammer (86) for striking by the hammer (86) and by a plurality of springs (68, 68a, 68b) of selected spring tension provided on said rod (64) inside said coupling housing (2), said springs (68, 68a , 68b) interposed between said rod plate (65) and said one end of said coupling housing (2) for tensioning said rod (64) responsive to operation of the pulling apparatus and advancing said pipe bursting head (43) toward the

pulling apparatus responsive to said operation of the hammer (86).

4. A stored energy coupling for connecting a pipe bursting head (43) and a hammer (86) to a pulling apparatus, characterized by a coupling housing (2) carrying the hammer (86), said coupling housing (2) connected to the pipe bursting head (43); a rod (64) having one end slidably disposed in one end of said coupling housing (2) and a rod plate (65) carried by said one end of said rod (64), said rod plate (65) disposed in spaced-apart relationship with respect to the hammer (86) and the opposite end of said rod (64) connected to the pulling apparatus; and a striker plate (85) fixed in said coupling housing (2) between the hammer (86) and said rod plate (65), wherein said rod plate (65) moves toward the hammer (86) in said coupling housing (2) responsive to striking of said striker plate (85) by the hammer (86) against the tension applied to the rod (64) by the pulling apparatus, for insulating the pulling apparatus from stress by said striking of the striker plate (85) by the hammer (86).

5. The stored energy coupling of claim 4 characterized by at least one bias mechanism (67) provided in said coupling housing (2) between said rod plate (65) and said one end of said coupling housing (2) for augmenting said tension applied to said rod (64) responsive to said striking of said striker plate (85) by the hammer (86) and advancing of said pipe bursting head (43) toward the pulling apparatus, wherein said at least one bias mechanism (67) may comprise at least one spring (68, 68a, 68b) provided in said coupling housing (2) between said rod plate (65) and said one end of said coupling housing (2).

6. A stored energy coupling for a pipe bursting apparatus, characterized by a coupling housing (2); a pipe bursting head (43) carried by said coupling housing (2); a pulling apparatus spaced- apart from said pipe bursting head (43); an elongated pulling member (64, 40) having one end connected to said pulling apparatus and the opposite

end of said pulling member extending through said pipe bursting head (43) and into one end of said coupling housing (2); a rod plate (65) terminating said opposite end of said pulling member (64 , 40) or a combination of said pulling member (64, 40); at least one spring (68, 68a, 68b) disposed on said pulling member (64, 40) or a com bination of said pulling member (64, 40) between said rod plate (65) and said one end of said coupling housing (2); a hammer (86) disposed in said coupling housing (2) in spaced-apart relationship with respect to said rod plate (65); and a striker plate (85) fixedly provided in said coupling housing (2) between said rod plate (65) and said hammer (86), wherein tensioning of said pulling member (64, 40) or a combination of said pulling member (64, 40) by operation of said pulling apparatus compresses said spring (68 , 68a, 68b) and striking of said striker plate (85) by said hammer (86) intermittently decompresses said spring for augmenting advancement of said pipe bursting head (43) toward said pulling apparatus.

7. The stored energy coupling of claim 6 characterized in that said at least one spring comprises a plurality of springs (68, 68a, 68b) provided in said coupling housing (2) on said pulling member (64, 40) or a combination of said pulling member (64, 40) between said rod plate (65) and said one end of said coupling housing (2), wherein said pulling member (64, 40) may comprise a steel rod (64) or a steel cable (40) or a combination of said steel rod (64) and steel cable (40), and/or wherein said at least one spring may comprise a plurality of springs (68, 68a, 68b) of selected tension provided in said coupling housing (2) on said pulling member (64, 40) or a combination of said pulling member (64, 40) between said rod plate (65) and said one end of said coupling housing (2).

8. An apparatus for bursting a pipe characterized by a pipe bursting mechanism (43) for engaging the pipe (83); a stored energy

coupling (1 , 20, 30, 31 ) engaging said pipe bursting mechanism (43); a hammer (86) engaging said stored energy coupling rearwardly of said pipe bursting mechanism (43) for selectively striking said stored energy coupling; a pulling member (64, 40) having one end engaging said pipe bursting mechanism (43) for pulling said pipe bursting mechanism against the pipe (83); a hydraulic cylinder (78) spaced-apart from said pipe bursting mechanism (43) and a frame (101 ) carrying said hydraulic cylinder (78); a piston or ram (90) disposed in reciprocating relationship in said hydraulic cylinder (78) and a pulling member-gripping element (32) carried by said piston or ram (90), said pulling member gripping element alternately gripping and releasing the opposite end of said pulling member (64, 40) from said one end; and a frame gripping element (5) carried by said frame (101 ) in spaced-apart, substantially linearly-aligned relationship with respect to said pulling member gripping element (32), for alternately gripping and releasing said pulling member (64, 40), wherein said pipe bursting mechanism (43) progressively cuts and bursts the pipe (83) along the length of the pipe as said piston or ram (90) advances in said hydraulic cylinder (78), said pulling member (64, 40) pulls said pipe bursting mechanism (43) against the pipe (83) and said hammer (86) strikes said stored energy coupling (1 , 20, 30, 31 ), responsive to alternate gripping of said pulling member by said pulley member gripping element (32) and said frame gripping element (5).

9. The apparatus of claim 8 characterized in that said pipe bursting mechanism comprises a pipe bursting head (43) for engaging the pipe (83) and a bias mechanism (67) provided in said stored energy coupling (20, 30, 31 ) for engaging said pulling member (64, 40) and biasing said stored energy coupling and said pipe bursting head (43) against the pipe (83) as said piston or ram (90) in said hydraulic cylinder (78) applies tension to said pulling member, wherein said pulling member may comprise a steel rod (64) or a steel cable (40) or a combination of

steel rod (64) and steel cable (40).

10. An apparatus for pulling a workload characterized by a pulling member (64, 40) for connection to the workload; a hydraulic cylinder (78) disposed in spaced-apart relationship with respect to the workload and a frame (101) mounting said hydraulic cylinder (78); a ram (9O) disposed for reciprocation in said hydraulic cylinder (78); a first gripping element (32) carried by said ram (90) and a first set of wedges (35) adjustably provided in said first gripping element (32) for selectively gripping said pulling member (64, 40); a first spring (32) adjustably engaging said first set of wedges (35) for adjusting the grip of said first set of wedges (35) on said pulling member; a second gripping element (5) carried by said frame (101), said second gripping element (5) disposed in substantially linearly-aligned, spaced-apart relationship with respect to said first gripping element (32); an adaptor body (8) carried by said second gripping element (5) and a body cone (8b) provided in said adaptor body; a second set of wedges (12) adjustably seated in said body cone for selectively gripping said pulling member (64, 40); and a second spring (5a) adjustably engaging said second set of wedges (12) for adjusting the grip of said second set of wedges on said pulling member (64, 30), wherein the workload is advanced toward said hydraulic cylinder (78) responsive to reciprocation of said ram (90) and alternate gripping of said pulling member (64, 40) by said first set of wedges (35) in said first gri pping element (32) and said second set of wedges ( 12) in said second gripping element (5).

11. The apparatus of claim 10 characterized in that said rarn (90) has a large ram end (90a) carrying said first gripping element (32) and a small ram end (90b) extending from said large ram end (90a), wherein said ram (90) rapidly reciprocates rearwardly on said pulling member (64, 40) as said first set of wedges (35) releases said grip on said pulling member and said second set of wedges (12) grips said

pull Ing member, which may be a steel rod (64) or a steel cable (40) or a combination of said steel rod (64) and a steel cable (40), and/or characterized by a load cell (53) provided in said second gripping element (5) and engaging said adaptor body (8) for determini ng the tension in said pulling member (64, 40) or a combination of said pulling member (64, 40) responsive to said gripping of said pulling member by said second set of wedges (12) in said second gripping element (5), wherein said ram (90) may have a large ram end (90a) carrying said first gripping element (32) and a small ram end (90b) extending from said large ram end, wherein said ram (90) rapidly reciprocates rearwardly on said pulling member (64, 40) as said first set of wedges (35) releases said grip on said pulling member and said second set of wedges (12) grips said pulling member. 12. An apparatus for pulling a workload characterized by a pulling member (64, 40) or a combination of said pulling member (64, 40) for connection to the workload; a hydraulic cylinder (78) disposed in spaced-apart relationship with respect to the workload and a frame (101) mounting said hydraulic cylinder (78); a ram (90) disposed for reciprocation in said hydraulic cylinder (78); a first gripping element (32) carried by said ram (90) and a first set of wedges (35) adjustably provided in said first gripping element (32) for engaging said pulling member (64, 40); a first spring (33) adjustably engaging said first set of wedges (35) for adjusting the grip of said first set of wedges on said pulling member (64, 40); a second gripping element (5) carried by said frame (101 ), said second gripping element disposed in substantially linearly-aligned, spaced-apart relationship with respect to said first g ripping element (32); an adaptor body (8) carried by said second gripping element (5) and a body cone (8b) provided in said adaptor body (8); a second set of wedges (12) adjustably seated in said body cone (8b) for engaging and selectively gripping said pulling member (64, 40); a second spring (5a) adjustably engaging said second set of wedges (12) for adjusting the grip of said

second set of wedges on said pulling member (64, 40); and a load cell (53) provided in said second gripping element (5) and engaging said adaptor body (8) for determining the tension in said pulling member (64, 4-0) responsive to said gripping of said pulling member by said second set of wedges (12) in said second gripping element (5), wherein the workload is advanced toward said hydraulic cylinder (78) responsive to reciprocation of said ram (90) and alternate gripping of said pulling member (64, 40) by said first set of wedges (35) in said first gripping element (32) and said second set of wedges (1 2) in said second gripping element (5).

13. A method for connecting a pipe bursting head to a hydraulic cylinder pulling apparatus by a pulling member (64, 40) or a combination of said pulling member (64, 40) extending between the pipe bursting head (43) and the hydraulic cylinder pulling apparatus, characterized by the step of interposing a stored energy coupling (1 , 20, 30, 31) between the pulling member (64, 40) or a combination of said pulling member (64, 40) and the pipe bursting head (43).

14. The method according to claim 13 characterized by the step of providing at least one bias mechanism (67) in the stored energy coupling (20, 30, 31) and engaging the bias mechanism with the pulling member (64, 40) or a combination of said pulling member(64, 40) for applying tension on the pulling member or a combination of said pulling member (64, 40).

15. A method for bursting existing pipe and pulling new pipe underground characterized by providing a hydraulic cylinder (78) having a reciprocating ram (90) and a first gripping element (32) on the reciprocating ram (90); mounting the hydraulic cylinder (78) in a frame (101); providing a second gripping element (5) in the frame (101 ), the second gripping element disposed in spaced-apart, substantially linearly aligned relationship with respect to the first gripping element (32);

positioning a pipe bursting apparatus (43) against the existing pipe (83); connecting one end of a pulling member (64, 40) or a combination of said pulling member (64, 40) to the pipe bursting apparatus (43) and extending the opposite end of the pulling member (64, 40) or a combination of said pulling member (64, 40) through the existing pipe (83) and through the first gripping element (32) and the second gripping element (5), and bursting the existing pipe (83) and pulling the new pipe (80) in the location of the existing pipe responsive to reciprocation of the ram (90) in the hydraulic cylinder (78) and alternate gripping of the pulling member (64, 40) by the first gripping element (32) and the second gripping element (5). 16. The method according to claim 15 characterized by the step of providing a load cell (53) in the second gripping element (5) for determining the tension in the pulling member (64, 40) or a combination of said pulling member (64, 40) when the pulling member is gripped by the second gripping element (5).