EP0115524A1

EP0115524A1 - Compression tool operator

Info

Publication number: EP0115524A1
Application number: EP19830902676
Authority: EP
Inventors: William P. Ware
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-08-05
Filing date: 1983-08-05
Publication date: 1984-08-15
Also published as: WO1984000510A1

Abstract

Du fluide à haute pression est dévié du système hydraulique de levage d'un camion à benne (BT) pour charger un outil à compression (C) en actionnant manuellement une soupape de commande (10) qui charge simultanément le piston (46) d'un cylindre de refoulement de conduite de retour (40) avec du fluide à haute pression provenant du système hydraulique de levage du camion. Cela crée une chambre à basse pression (50) dans laquelle l'outil refoule de fluide lorsque la soupape de commande est réglée dans sa position de détente pour retirer l'outil (C). Dans un mode de réalisation, le fluide sous pression qui charge l'outil (C) est bloqué par la soupape de commande (10) lorsque celle-ci met l'outil (C) en mode de refoulement; dans un deuxième mode de réalisation, une soupape détectant une différence de pression (70) s'ouvre en permettant au fluide de s'écouler depuis le circuit d'alimentation du camion directement vers le retour, lorsque la soupape de commande (10) est ainsi réglée.High pressure fluid is diverted from the hydraulic lifting system of a dump truck (BT) to load a compression tool (C) by manually operating a control valve (10) which simultaneously loads the piston (46) with a return line delivery cylinder (40) with high pressure fluid from the truck's hydraulic lift system. This creates a low pressure chamber (50) into which the tool discharges fluid when the control valve is set to its released position to remove the tool (C). In one embodiment, the pressurized fluid which charges the tool (C) is blocked by the control valve (10) when the latter puts the tool (C) in delivery mode; in a second embodiment, a valve detecting a pressure difference (70) opens allowing the fluid to flow from the supply circuit of the truck directly to the return, when the control valve (10) is thus settled.

Description

COMPRESSION TOOL OPERATOR This invention relates to novel means and apparatus by which a compression tool or other hydraulically operated tool is operatively connected to a supply of pressured fluid.

It is known to connect electric conductors, cables, wires, or rods and the like by assembling them into a cable shoe, terminal lug, sleeve or other connector and compressing the assembly so as to crimp and thereby mechanically interlock the assembled components and establish a strong solid connection therebetween, both structurally and electrically. The tools employed for this purpose commonly comprise a fixed jaw or anvil and an axially movable jaw or ram between which the assembled conductors and connector are inserted; and the movable jaw is h draulically actuated to crimp the assembly therebetween. Examples of such crimping tools are disclosed in Dischler U.S. Patent No. 3,619,885 and Lytle et al . U.S. Patent No. 4,136,549. Potential users of such tools, for example, include electric power companies, telephone companies and the like.

In recent years it has become common for these companies to equip their trucks with elevatable buckets or platforms on which a workman can position himself and be raised thereby to work on overhead high tension lines as well as associated components such as a transformer or supporting cables. Commonly, such hydraulic lift systems are designed to build up a pressure in the order of 1500 psi to 3000 psi (96 bar to 193 bar) which is more than adequate to operate the crimping tool. Usually, at least auxiliary controls for operating the bucket lift hydraulics are already mounted on the bucket so that the workman can maneuver himself into and out of the area in which he is working. Such a bucket lift system is therefore conveniently available to be tapped to power the crimping tool . However, for reasons of safety the bucket truck manuf cturers intentionally build "back pressure" into the return line of such lift systems which will assure that the return line to the sump on the lower pressure side of said systems always contains fluid under some pressure usually in the order of 45 psi to 90 psi (2.9 bar to 5.8 bar). This is to guard against the possibility that the return line of the hydraulic lift system may empty of fluid (cavitate) and in so doing create an electrical capacitance should the truck be accidentally grounded, for example, to high tension electrical lines in the area in which the workman is working, and thereby set up a potentially undesirable and dangerous explosive condition. Although this back pressure in the return line of the tapped lift system is therefore important to maintain, it also prevents the axially movable jaw or ram of the crimping tool from retracting at the end of its compression stroke.

Thus a first important object of this invention is to provide means such as a control valve through which the compression tool and more particularly its ram can be loaded from the pressured side of the hydraulic bucket lift^' system to drive the compression tool to effect the crimping act and then be automatically reset to permit repeat of the crimping act.

In accordance with this invention the problem is overcome by locating a scavenging cylinder in communication with the return line which connects the discharge of the tool to the return side or sump of the hydraulic bucket lift system. This scavenger cylinder contains a piston which is simultaneously actuated by the force of the pressured fluid which is coupled to operate the tool when the control valve is moved into its operating position. This causes the fluid content of the scavenger cylinder to discharge into the return line so as to create a low pressure chamber in communication with the compression tool to receive the fluid which discharges from the tool when the control valve is reset to disconnect the tool from the pressured side of the hydraulic bucket lift system.

^' •r H»-r^,-^," ϊ ' " '-^{~ ^~ Λ}" 7 ^OMPI The low pressure chamber thus temporarily created in the return line to the hydraulic lift system permits the tool to exhaust independent of the back pressure which has been built into the bucket lift hydraulic system. Drainage of the tool therefore proceeds automatically and independent of the workman's attention.

Thus a feature of the invention is that each time the control valve is actuated to operatively load the compression tool, it is also discharging the scavenger cylinder of the fluid which had previously drained thereto from the compression tool to allow retraction of its ram.

Another feature of the invention is that both the loading of the compression tool to effect its crimping act and the discharge of the fluid drained into the scavenging cylinder to effect the tool retraction are initiated by the high pressure output of the bucket truck elevating system which is tapped by the control valve.

Still another feature of the invention is the provision of fluid flow check means in the return line through which the tool connects to the back pressurized side of the bucket elevating system such that the fluid, discharged from the scavenging cylinder exits to the sump of the bucket elevating system and not to the tool.

In a preferred form of the invention the scavenger cylinder piston is loaded against a spring which acts on the piston to evacuate the cylinder causing the system to retract and create the low pressure chamber into which the tool discharges when the control valve is returned to its "off" position.

In a modification of the invention, a pilot-operated shuttle valve is also actuated by the high pressure fluid from the bucket lift hydraulic system which allows the pressurized fluid to move against the piston and discharge the scavenger reservoir to return. On completion of the crimping act and reconnection of the tool to the return line, the shuttle valve relocates and opens the high pressure side of the scavenger piston to the return line. In an alternative embodiment of the invention, means are also provided such that when the tool control is in its "off condition", the tool does not operate and the flow of pressured fluid is diverted directly to the truck return, thus dropping the pressure to a lower valve and preventing heat build up in the fluid with consequent possible damage to the truck hydraulic lift system including components such as the pump, truck valve and seals.

A feature of the invention is that by-passing of the tool is initiated automatically and in response to actuation of the tool control valve which selectively loads and unloads the tool to effect the crimping function.

Thus, in accordance with the invention flow of the fluid to the tool is blocked in the off condition of the tool control valve. The pressurizing pump continues to operate but the fluid flows directly into the return to the lower pressure sump.

In the operated condition of the tool control valve the force of the pressure fluid is applied both against the compression tool to effect the crimping act and against the scavenger cylinder so that it empties its reservoir of fluid to the truck pump return readying the scavenger cylinder to receive the fluid which drains from the tool and allows its ram to retrct. At the same time as the crimping act terminates, the full pressure fluid is also diverted to open the differential pressure sensing valve so that the fluid from the pump as it continues to run by-passes the tool and flows directly to the truck sump at a reduced pressure until the tool control valve is again operated to repeat the crimping function.

As afterward more completely explained, the invention and the illustrated embodiments thereof represent a simple and inexpensive solution to what would otherwise be a serious problem. The structure is uncomplicated to manufacture and at the same time it is both simple and effective in its operation. The structure is also compact and it may be conveniently stored in a provided tray attached to the bucket where it is readily accessible to the workman.

Many other objects, advantages and features of the invention will be once apparent or will become apparent upon further consideration of the preferred embodiments of the invention which now will be described.

Referring however first to the drawings which accompany the application,

Figure 1 illustrates the invention mounted on the bucket at the upper end of an articulated boom which is hydraulically powered from the bucket lift system to locate the workman in a position, for example, to work on overhead high tension electrical wires;

Figure 2 illustrates the bucket on a somewhat larger scale and shows a typical location for the controls which operate the bucket elevating system and the crimping tool;

Figure 3 (sheet 2) is a sectional view taken longitudinally of the ada-pter (return line scavenger cylinder) and the manually actuated control valve which operates the compression tool;

Figures 4, 5, and 6 (sheet 2) are sectional views, taken through the control valve along lines 4-4, 5-5 and^" 6-6 as indicated in Figure 3;

Figure 7 (sheet 1) is an end view of the control valve and shows details of the lever-operated actuator for the control valve;

Figure 8 (sheet 1) is a fragmented side elevational view of said end of the control valve and shows further details of the assembled valve actuator;

Figures 9 through 12 (sheet 3) are schematic views of the valve control adapter and illustrate the fluid flow through the different settings of the control valve;

Figure 13 (sheet 3) illustrates a modification of the invention;

Figure 14 (sheet 4) illustrates a further embodiment of the invention according to Figure 3 (sheet 2) wherein a differential pressure sensing valve is connected across the pressure and return lines in by-passing

- relation to the compression tool;

Figure 15 is an end view of the differential pressure sensing valve shown mounted to the scavenger cylinder in Figure 14; the views being taken along line 15-15 of Figure 14 looking in the direction indicated by the arrows;

Figure 16 is a sectional view taken axially of the differential pressure sensing valve along line 16-16 of Figure 14, the differential pressure sensing valve being shown in part by full lines;

Figure 17 is a partially sectioned view of the differential pressure sensing valve as it is illustrated in Figure 14 but as shown on a larger scale and with parts sectioned to illustrate details of its construction; and

Figures 18 and 19 (sheet 5) are schematic views of the apparatus according to Figures 14-17; Figure 18 illustrating the connection of the scavenger cylinder and the differential pressure sensing valve in the off condition of the control valve and Figure 19 showing said connections in the operated condition of the tool control valve.

Referring now more particularly to the several- views wherein like parts are identified by like reference^" - numerals, BT indicates in Figure 1 a so-called bucket truck of conventional construction on which is mounted a rotatable turn table T. The turn table T supports one end of an articulated boom B, the other end of which supports a bucket B in which a workman W locates himself. Levers (a) located on the front side of the bucket are operable by the workman so that he can be raised to reach a position for working, for example, on overhead power lines indicated generally at L . In Figure 1 the workman W is shown in the act of connecting a secondary line L' to a main power line L using a crimping or compression tool indicated generally at C.

As illustrated in Figure 2, tool C has both a fixed jaw or anvil A and an axially movable jaw or ram A' , which engage about an assembly of lines L and L' inserted within a connector sleeve. The assembly is mechanically and electrically interlocked by applying pressure to the

^**- ram A' which urges it to compress or crimp the assembly therebetween and the fixed anvil A.

A feature of this invention is that the tool C is releasably coupled to the tool port 16 (Figure 3) of a control valve generally indicated at 10 which is manually operable so as to selectively connect the tool to the pressurized output of a hydraulic pressurized fluid pump (not shown) but which is also relied upon to operate the boom and the rotatable turn table on which it is mounted in order to position the bucket in a position above ground where the workman can reach the overhead work area.

Considering now Figure 3 with Figures 1 and 2, in a first embodiment of the invention, the control valve 10 which operates the compression tool C comprises a housing 12 having a stepped central bore 13, the larger end of which is closed by a plug 14 having a threaded port 16 into which the tool C is threadedly coupled. In said bore 13 of the valve housing 12 is an axially slidable spindle 18 provided with an actuating rod 20 which protrudes from its opposite end for engagement by a manually operated lever 21. In (Figures 7, 8), lever 21 is shown pivotably mounted to the valve housing 12 by a pinned connection 22. At 23 is a second pin which extends through opening 24 in hinge plate 25 and limits the angle through which lever 21 is swingable between the pressure and return positions of the spindle which moves axially through the bore 13 of. the control valve to load and discharge the tool C.

In the illustrated "off" position of the control valve 10, its return port 26 is connected via return hose R through releasable coupling 29 (Figure 2) to the return side of the pressurized fluid pump which also supplies fluid to elevate the truck bucket B in which the workman operates. At 28 is a pressure port which connects to hose P which is similarly coupled at 27 but to the pressured fluid side of said pump.

In the illustrated "off" position of the control valve 10, its return port 26 communicates via recess 32 into the peripherally wide annular recess 34 in the valve spindle 18 (Figure 5). Said annular recess 34 also communicates with port 36 via recess 35 as illustrated by

Figure 5. The pressure port 28 as shown by Figure 6 also communicates with the interior of the bore in which the spindle 18 operates. However, it will be noted in Figure

6 that spindle recess 34 is suitably dimensioned that in the illustrated "off" position of the control valve, it is closed to the pressure port 28. On the other hand, in

- the "operating" position of the valve spindle 18, the pressure port 28 communicates through said annular recess 34 of the spindle 18 to tool port 16 as aforedescribed while the return port 26 is disconnected therefrom. Thus in the illustrated "off" position of the control valve, pressure tool C drains through port 26 to the return R, and in the "operating" position of the control valve the tool C is loaded with the full force of the fluid entering via pressure hose P from the pressured side of the hydraulic pressurized fluid sump of the truck. However the return is closed.

A feature of this invention is that means are provided such that in the loading of the tool through tool connection port 16, a fluid evacuated chamber or reservoir^*

- is created to receive the fluid which must drain from the tool to permit retraction of the tool when the tool is disconnected from the high pressure output of the hydraulic pressurizing pump and reconnected to the return line. This capacity to drain the tool is independent of the pressure present in the return side of the pressurized fluid pump.

In Figure 3, said means is illustrated as comprising a return line scavenger system (or cylinder) identified generally at 40. Said scavenger 40 comprises a small dia etered high pressure chamber 42 containing a piston 44 which like the tool C Is also loaded by the full force of the pressurized fluid. As illustrated, said fluid flows via port 36 into hose line S and thereby is available to drive or force piston 46 in the larger diametered low pressure chamber 50 against the force of compression spring 48. This causes the fluid content of the larger chamber

TT π r»

"δ 50 to discharge through exit 52 into the return pipe line illustrated at 54.

As shown, pipe line 54 is connected at one end via hose R to return port 26 of the control valve, its opposite end being connected to a second hose line R which leads to the sump side of the fluid pressurizing pump. Between return port 26 and exit 52 of the scavenger cylinder 40 is a first one-way check valve 56 which permits flow of fluid from the return port to the sump but not in reverse. A second one-way check valve 58 is also located in said pipe line 54 but on the return side of the exit 52 from the scavenger cylinder 40. This valve 58 permits flow of fluid from the scavenger cylinder to the return of the sump. Check valve 56 is so designed that it opens at a lower pressure than will the second check valve 58 which in turn has an opening pressure of less than that of the pressure fluid with which the scavenger cylinder is loaded from the hydraulic pressurizing pump through the control valve 10.

It will thus be evident, as schematically illustrated in Figure 9, that in the static or off condition of the control valve 10, compression tool C is cut off from the pressure side of the hydraulic pressurizing pump (hose P) . However upon manual actuation of lever 21, rod 20 relocates the valve spindle 18 in the control valve 10 so that it is now open to the flow of pressurized fluid from port 28 (P) which loads the compression tool . Simultaneously, the high pressure side of the scavenger cylinder piston is pressure-loaded through hose S as illustrated in Figure 10 by the arrows with solid heads. In this condition of the control valve, compression tool C is cut off from the return hose represented at R and loaded by the full force of the truck fluid supply. Simultaneously said pressure fluid is also diverted through hose S as indicated by the solid head arrrows and loads the scavenger cylinder piston against the resistance of spring 48 (Figure 3) . Thus, any fluid present in the cylinder is forced through exit 52 into the return line 54, check valve 56 however resisting flow of said pressurized fluid back to the control valve 10. The fluid discharged from the scavenger cylinder is therefore forced through the second check valve 58 into the pressure pump

; sump. Thereafter, upon completion of the crimping act, the operating handle is released. This allows spindle actuating spring to relocate the spindle so that the tool discharges of its fluid through the control valve and into the return line. The pressure of the fluid discharging from the tool exceeds the pressure of the valve 56 wherefor the pressure load on the scavenger cylinder piston is relieved and compression spring 48 is actuated to return the piston to its off condition as illustrated by Figure 9. As this occurs, the retreating scavenger cylinder piston in the larger chamber 50 creates space or reservoir into which the compression tool can drain of its fluid (with which it was previously loaded as illustrated by Figure 10). Simultaneously, as illustrated by the open arrowheads, the fluid force on the piston is now cut off from the force of the hydraulic pressurizing pump so that fluid on the pressure side of the scavenger piston discharges into hose S and through the control valve into the return line to^"

^'_ discharge with the fluid discharging from the tool. In the next actuation of the control valve to again load the compression tool, the pressurized fluid from the pump now acts on the high pressure piston 44 pressurizing the fluid stored in the large chamber causing it to discharge through check valve 58 into the sump of the hydraulic pressurizing pump.

The arrangement is simple but effective and is independent of the attention of the workman operating the compression tool loading since all that is required of him is to actuate the operating handle 21 to initiate the loading of the tool, his release of the operating lever causing the tool to drain automatically of its previously loaded fluid and is independent of any back pressure in the return side of the pressurized fluid pump.

-^On∑ In an alternate form of the invention as illustrated by Figure 13 under some circumstances it may be desirable to provide a pilot-operated shuttle valve such as illustrated at 60 in the cylinder line S. In this ^■ modification, the shuttle valve 60 is simultaneously loaded from hose S through pilot coupling 62 indicated by dotted lines which relocates the shuttle valve to load the high pressured side of the cylinder piston against the compression spring 48 as in the first embodiment. However, upon return of the control valve to its off condition, the pressure of fluid on the shuttle valve 60 is removed such that it returns under the force of a spring (not illustrated) and allows the compression spring 48 to cause the fluid on the high pressure side of the piston cylinder to discharge through the return line R downstream of check valve 58 thereby to facilitate storage of fliud in the scavenger cylinder chamber which drains from the compression tool.

In the off condition of the tool control valve the first described embodiment of the invention, pressure port 28 is closed by spindle 18 so that with continued- operation of the pressured fluid supplying pump of the truck, unless special precautions are observed, overheating of the hydraulic fluid and damage to the bucket lift system of the truck is a possibility. Truck hydraulic supply systems vary greatly from manufacturer to manufacturer. Some supply systems may include an accumulator, unloading valve, pressure relief valve or other means of absorbing the hydraulic shock or excess pressure and flow when the equipment is shut off. Other systems may be provided only with a relief valve set to open at a maximum pressure.

Referring therefor next to Figures 14 through 19, a second embodiment of the invention is illustrated as comprising tool by-pass means through which the pressured fluid supplied by the hydraulic pressuring pump discharges directly to the sump on the low pressure size of said pump when the load on the crimping tool is relieved and the tool function is interrupted. The problem of fluid overheating

, , . mm. -, --_ - __-_ „ - ..--, _-, r-. r_. --r. ^{O PI} is thus substantially eliminated.

In said views such means are illustrated as comprising a differential pressure sensing valve assembly indicated generally at 70. Said valve assembly comprises a unit which may be readily mounted to the adapter comprising the return-line pressure fluid scavenger 40 af or edes cr i b ed by detaching the high pressure port supporting plate 43 (Figure 3) from the adapter housing and using the same bolts to secure said unit in the place of said plate 43; thereafter making the appropriate hydraulic fluid connections as hereafter described.

Turning therefore now to Figure 14, the differential pressure sensing valve assembly 70 comprises a main housing 72 which is bolted to the left-hand end of the return line pressure fluid scavenger 40 and contains a cavity 74 into which a ported sleeve 76 is threadedly secured by a retaining nut 78 which in turn is threadedly connected to housing 72. Considering now also Figure 17 with Figure 14, the outer wall of sleeve 76 is so shaped that with the cavital wall 80 of housing 72 it defines first and second annular disposed grooves or channels 82, 84 which- are sealed from each other by 0-rings 86.

Axially slidable within sleeve 76 against a compression spring 90 is a spindle 88 having a blind bore 92 the open end of which is loaded with fluid under pressure from the truck supply via pressure line P. In Figure 17 PT indicates the end of such pressure line which connects to the pressure fluid supply and P indicates the opposite end thereof which connects to the pressure port 28 of the control valve 10. At 94 are a series of holes through sleeve 76. In Figure 17, said holes 94 are shown closed by the spindle 88. However, when force is applied to the spindle by loading of its fluid bore 92, the spindle moves to the left of Figure 17 uncovering holes 94 so that the pressured fluid from line P can directly flow around the right-hand end of the spindle 88 to the return line RT (port 95) , compression spring 90 normally resisting said axial displacement so that the full force of said pressured fluid

^*- flows through line. P to load the tool C as before described in connection with the Figure 3 embodiment of the invention. At 96 a second set of holes provide communication between channel 82 and cavity 90 so as to return the spindle to its illustrated position which interrupts flow of fluid therethrough for the pressure line P to the return line R , the operation of which is schematically illustrated by Figures 18 and 19.

Referring, next to Figures 18 and 19, the operation of the invention to control the crimping act will be briefly summarized. In the off condition of the tool control valve 10 as illustrated by Figure 18, pressured fluid from the truck supply is blocked at 100 and the tool C drains through the return to large chamber 50. The differential pressure sensing valve 70 is open so that fluid under pressure from the truck supply flows directly therethrough to the return line.

To initiate the crimping act, the control valve 10 is manually reset as illustrated in Figure 19. In said operated condition of the tool control valve, pressurized fluid flows via line P to junction 102 where it divides- so that as pressure is applied to load the tool C to effect the crimping act, the pressurized fluid also enters line S and flows through bores 98, 99 (Figure 16) to equalize the pressure admitted through port 103 or the opposite side of the pressure differential valve so that spring 90 moves spindle 88 closing the by-pass and so that pressured fluid from P is concentrated on the control valve to operate tool C. At the same time the pressured fluid is also diverted from bore 98 through 97 against piston 44 causing larger diametered piston 46 to force fluid from chamber 50 through check valve 58 into the truck return.

At completion of the crimping act, the workman releases his hold on operating lever 21. This causes the control valve 10 to return to its off position illustrated by Figure 18. Further pressured fluid flow to the tool is interrupted, and the pressure differential sensing valve opens so that the pressure thereof is no longer on the

control valve. As in the first described embodiment, the force on spring 48 in the return line scavenger unit 40 is relieved converting its chamber 50 into a reservoir to receive the fluid draining from the tool C, allowing the tool ram to retract.

From the aforesaid description, it will be apparent that all of the recited objects and advantages and features of the invention have been demonstrated as obtainable by conveniently operated apparatus and both economical and simple to manufacture.

Having described the invention what is claimed is:

Claims

CLAIMS ;

1. Apparatus for connecting a compression tool to a high pressured fluid supply system comprising a control valve having a port to which the tool ' is connected; a pressure line connectable to the pressured side of said fluid supply; a return line connected to the return side of said fluid supply; and hand-operated control means which are movable between a normally closed position in which the tool port connects to the return line and an actuated position in which the tool port is disconnected from the return line and is connected to the pressure line so that the tool loads from the pressurized fluid supply system; a return-line-scavenger pump cylinder containing a fluid exhaust piston dividing said cylinder into a high pressure chamber having an entrant end connected to the tool port and a larger low pressure chamber having an exit which opens into the return line; and spring means urging said piston toward the entrant end of said cylinder; the force of said spring means being less than that of the pressurized fluid supply system such that in the actuated position of the actuating means the piston overcomes the force of the spring means causing fluid to discharge from the low pressure chamber into the return line creating a reservoir into which the tool discharges its fluid when the actuating means is returned to its normally closed position.

2. Apparatus according to Claim 1 wherein the return line contains means which inhibit flow of fluid from the discharge end of the return-line-scavenger pump cylinder into the tool port while permitting flow of fluid therefrom through the return line to its connection to the pressurized fluid supply system.

3. Apparatus according to Claim 1 wherein the return line contains a first check valve between the tool port and the discharge end of the return-line-scavenger pump cylinder which permits fluid flow from the tool port to the cylinder discharge end but inhibits flow of fluid in the reverse direction.

4. Apparatus according to Claim 3 wherein the return line contains a second check valve between the discharge end of the cylinder and the end of the return line which connects to the pressurized fluid supply system, said second check valve permitting flow of fluid from the discharge end of the cylinder to the pressurized fluid supply system but not in reverse from said fluid supply system.

5. Apparatus according to Claim 4 wherein the first check valve opens to a flow of fluid from the tool port at a pressure lower than that at which the second check valve opens.

6. Apparatus according to Claim 1 wherein normally open valve means connect the pressure line to the return line in by passing relation to the tool port, said valve means being closed by actuation of the hard-operated control to its actuated position in which the tool loads from the pressurized fluid supply system.

7. Apparatus operatively connecting a compression tool to a pressured fluid supply system comprising, in combination, a control valve having a port to which the tool connects for hydraulic fluid operation; a pressure line to which the pressured side of said fluid supply system is connected; a return line which connects to the low pressure side of said fluid supply system; actuator means movable into and out of an operating position in which the tool port is connected to the pressure line for loading of the tool from said hydraulic fluid supply source;

CM V :τ an adapter containing a fluid actuated member which is simultaneously armed with pressured fluid from said supply system when the actuator means is moved into its operating position to load the tool; and the fluid actuated member when thus armed discharging the adapter of fluid into the return line to create a reservoir into which the tool discharges its fluid when the actuator is moved out of its operating position.

8. Apparatus according to Claim 7 including a flow restrictor in the pressure line which limits the flow delivered to the tool port.

9. Apparatus according to Claim 7 wherein the actuator means is manually operated against a spring which moves the actuator means out of its operating position to reset the apparatus.

10. Apparatus according to Claim 7 wherein a normally open differential pressure sensing valve connects the pressure line to the return line in by-passing relation to the tool port, said valve being closed in response to the arming of the fluid actuated member of the adapter such that the full pressure of the supply system is directed_, to the tool when it is connected to the pressured side of

^'the fluid supply system.

11. A r eturn-1 ine-scavenger system for a compression tool which is loaded from the supply side of a high pressure developing pump in response to actuation of a control valve from its "at-rest" position to an "operating" position, the "at-rest" position of the control valve opening the tool for fluid drainage into the sump of said high pressure fluid pump, said scavenging system including a cylinder having a low pressure chamber which connects into the return from the tool to the sump; a high pressure chamber which connects through the control valve to the output of said fluid pressure pump; eans in said high pressure chamber which are actuated by the output of said pump to cause the piston in said low pressure chamber to empty into the return to the sump side of the pump; whereby space is created in the return line between the tool and the sump to receive the fluid discharged by the tool when the control valve is locked in its "at-rest" position to drain the tool.

12. In combination, a compression tool having an anvil and an axially movable ram between which two or more elements are assembled to be connected by a crimping action thereon; a pressure line connecting the high pressured output of a hydraulic pressurizing pump to the compression tool for loading of the tool ram to effect said crimping action; a return line connecting the compression tool to the sump of said hydraulic pressurizing pump draining of the tool and thereby retraction of its ram at the end of the crimping act, said retraction of the tool ram being inhibited by back pressure in the sump side of said pump;^* and means operatively connected to said pressure line which effectively create a fluid evacuating chamber communicating with the return line as the tool is loaded with pressured fluid and into which the tool drains of fluid to permit retraction of the tool ram when the tool is disconnected from the high pressure output of the hydraulic pressuring pump and reconnected to the return line.

13. The combination of Claim 12 wherein the fluid draining into the fluid evacuated chamber is discharged therefrom to the sump under the force of the high pressured output of the pump which is exerted against said means to create the fluid evacuated chamber.

14. In combination, a compression tool having a fixed anvil and a movable ram between which are located elements such as an electric conductor and a connector to be crimped together by pressure loading of the tool; a tool control valve to which the tool is coupled; a pressure line through which the control valve connects to the high pressure fluid output of a fluid pressurizing pump; a return line through which the control valve connects to the sump of said fluid pressurizing pump; and valve means ported to said pressure line upstream of the control valve and to the return line downstream thereof in normally-open_,, by-passing relation to the tool; said tool control valve having a manually-operated valve closure which is movable into and out of an operated position in which the tool is connected to the pressure line and shuts off its communication to the return line so that the tool loads with pressurized fluid to effect said crimping action and in its off condition drains to the sump; and means actuated by the valve closure which close the tool by-passing valve means when the manually-operated valve closure of the tool control valve is moved into its operated position.

15. Apparatus for operating a compressor tool having a fixed anvil and a movable ram for crimping an electric cable or the like to a connector comprising, in combination, a tool control valve having a connection port to which the tool is removably coupled, a pressure port through which the control valve communicates with the high pressure fluid output of a fluid pressurizing pump, and a return port through which the control valve communicates with the -sump of said fluid pressurizing pump; a differential pressure sensing valve communicating with said pressure and return ports of the tool control valve, said differential pressure sensing valve being normally open and in by-passing relation to the tool connection port of said tool control valve;

:sτ the tool control valve having a manually-operated valve closure which in its operated position connects the tool port to the pressure port to load the tool through its connection port and in its off position connects the tool port to the return port; and said differential pressure sensing valve having means responsive to pressure-loading of the tool through the tool connection port in the operated position of the tool control valve closure which close the differential pressure sensing valve during the crimping act.