The present invention relates to an adaptor for connecting fuel or test-oil injection means to a receiving line of an injection test system.

An example of an injector which has already been proposed is shown in Figures 1, la and lb, in which :-

Figure 1 shows a part axial-sectional, part side view of an injector;

Figure la shows an axial-sectional view of a head of the injector shown in Figure 1 equipped with a nozzle member; and

Figure lb shows an axial-sectional view of a head of the injector shown in Figure 1 equipped with a nozzle member and also provided with an orifice plate.

In Figure 1 a generally T-shaped injector head 10 has an externally screw-threaded nozzle-attachment end 11. A passageway 12, through which test-oil passes when the injector means are in use or under test, extends from the base of the ^•• T" to that nozzle attachment end 11. At the base of the "T" there is an internally screw- threaded portion engaged by an externally screw-threaded end of an extension piece 13, the other end 14 of which is also externally screw-threaded to enable the head 10 to be attached to a line from an injection pump (not shown) under test or to enable a test to be made. Half-

way up from the base of the "T" there is a manual pressure release valve 16 in communication with the passageway 12.

An axially extending through-bore 17 is also formed in the cross-piece of the "T", which through-bore contains a spindle 18 which is urged by a helical spring 19 towards the nozzle attachment end 11.

Figure la. shows a nozzle member 20 fitted onto the nozzle attachment end 11. This is effected by means of a holding piece 22 which is threaded onto the end 11, and is provided with an internal shoulder 23 which engages a flange at one end of the nozzle member 20. The nozzle member 20 has a duct 24 which leads from that end of the nozzle member which abuts the head 10, to the nozzle constriction 28. The constriction 28 is normally blocked by a plunger 26. The latter extends through an axially extending cavity 27 in the nozzle member 20 and has a portion which fits into a recessed end of the spindle 18. When the injector is in use, test-oil is able to enter the nozzle member 20 via the passageway 12 in the head 10, and is also able to pass along the duct 24 in the nozzle member 20. Once sufficient test-oil pressure is built up in this way in the nozzle member 20, that pressure forces back the plunger 26 against the restoring force of the spring 19, to enable test-oil under pressure to be ejected through the constriction 28.

In Figure lb an enlarged holding piece 30 is illustrated instead of the holding piece 22 shown in Figure la _. , which contains an orifice plate 32 fitted immediately downstream of the nozzle member 20. Beyond the orifice plate 32 there is a further connection part 34 having an axially extending passageway in communication with the orifice in the orifice plate 32. In such an arrangement, the orifice plate 32, which has a single central hole, can be changed so as to suit different test conditions. This enables various desired test conditions to be achieved using respective different orifice plates with respective differently sized central holes, which plates are relatively simple to manufacture.

A previously proposed adaptor for such, an injector comprises a block with a plurality of cavities which receive respective injector nozzles, each cavity being in communication with a respective receiving line of the system. Each injector is held in position to inject test-oil into its associated cavity by means of a clamp secured by a bolt or by means of an arm cantilevered from a ratcheted pillar beside the injector.

When the test injectors have to be changed, either because the multi-line fuel injection pump which is under test is to be changed, or because the operating conditions of a pump under test need to be changed, such previously proposed adaptors may give rise to an

undesirably time-consuming operation.

The present invention seeks to provide a remedy.

Accordingly, the present invention is directed to an adaptor for connecting fuel or test-oil injection means to an input end of a receiving line, in which the adaptor is so constructed as to enable a quick-release device to be connected to it and disconnected from it.

This may provide the added advantage of a construction involving fewer machined parts, resulting in a cost-saving connection.

Preferably the adaptor is of generally tubular form, and is provided with connection means at one of its ends to enable it to be connected to the injection means and a formation on its outside at its other end to receive an engaging part of a quick-release device.

In a preferred embodiment the formation on the outside of the adaptor is an annular groove surrounding the axis of the adaptor.

The annular groove may advantageously, in cross- section, comprise a straight sloped down-stream side, a flat bottom, and an arcuate concave upstream side. This facilitates an easier quick-fit and quick-release.

Advantageously the interior of the adaptor is such as to enable it to accommodate the nozzle member of such injection means.

Preferably that part of the adaptor which accommodates the nozzle member has an enlarged internal

and external section.

The adaptor may be tapered on its outside from the enlarged section towards the said formation to accommodate a user's finger tips and thereby to facilitate manual removal of such a quick-release device more readily.

In one possible embodiment the adaptor contains an orifice plate.

Advantageously the interior of the adaptor is provided with a retaining formation which serves to retain the nozzle member of such injection means in place when the adaptor is in use.

In a preferred embodiment the retaining formation of the adaptor comprises a shoulder. The latter may be provided with an O-ring seal.

Advantageously the said connection means comprises an internal screw-thread. In that case, it is preferable for the adaptor to be provided with tightening means to enable it to be tightened on to the injection means.

Advantageously the tightening means comprise at least one flat on the outside of the adaptor.

In a preferred embodiment the said flat is one of a number of flats which give the outside of a part of the adaptor a hexagonal cross-section.

Alternatively, the tightening means may comprise at least one recess on the outside of the adaptor.

In a further possible construction, the tightening means comprise at least one hole extending inwardly from the outside of the adaptor.

Alternatively the said connector means comprises bolt member or members, which are attached via flanges provided on the ends of the adaptor and injection means.

Advantageously a sleeve of the adaptor extends beyond the said connection means away from the quick- release end. When the adaptor is in use, such a sleeve may embrace a part of the injection means to increase the resistance to shearing of the adaptor relative to the injection means.

The adaptor may comprise hardened steel.

Preferably the adaptor is constructed to enable it to withstand an internal pressure of substantially

2000psi(140 bar). This is to enable the adaptor to withstand very short instantaneous pulses of this pressure which may occur during use of the adaptor.

One form of the invention includes a quick- release device connected to such an adaptor.

In a preferred embodiment of that form of the invention, the engaging part of the quick-release device comprises a ball. The ball may be one of a number which surround the quick-release end of the adaptor. Advantageously the balls of the quick-release device are locked in place by an axially slidable locking sleeve. The latter may be resiliently urged towards its

locking position.

The present invention extends to a combination of such an adaptor and such injection means to which the adaptor is connected. The present invention also extends to a combination of such an adaptor, such injection means and such an orifice plate.

The present invention further extends to a combination of such an adaptor, such injection means and a quick-release device which is connected to the adaptor.

Examples of adaptors made in accordance with the present invention are shown in Figures 2 to 10, in which:-

Figure 2 shows an axial section of such an adaptor;

Figure 3 shows, on a larger scale, an axial section of a quick-release end of the adaptor shown in Figure 2;

Figure 4 shows an end view of the adaptor shown in Figure 2 looking towards the quick-release end thereof;

Figure 5 shows an exploded side, part axial- sectional view of an injector provided with such an adaptor; Figure 6 shows a side, part axial-sectional view of the injector and adaptor shown in Figure 5 in an assembled state, together with mounting means therefor;

Figure 7 shows a part side, part axial-sectional view of a connection between the adaptor and a quick- release device;

Figure 8 shows a part side, part axial-sectional view of a modified adaptor and injector;

Figure 8a shows a top end view of the injector shown in Figure 8;

Figure 9 shows an axial-sectional view of a further modified construction of an injector with a modified form of adaptor;

Figure 9a. shows a side view of a top part of the injector shown in Figure 9;

Figure 9b shows a top end view of the injector shown in Figure 9 as viewed from the injector head end; Figure 10 shows a part side, part axial- sectional view of yet a further modified injector and adaptor;

Figure 10a _. shows a top end view of the injector shown in Figure 10 as viewed from the injector head end; Figure 11 shows a part side, part axial- sectional view of a previously proposed injector head provided with a spray diffuser or spray damper;

Figure 12 shows a part side, part axial- sectional view of the injector head as illustrated in Figure 11 equipped with a modified form of adaptor;

Figure 13 is a side elevational, semi-sectional view of an assembly incorporating a further modified form

of adaptor;

Figure 14 is a side, semi-sectional view of parts of the assembly shown in Figure 13; and

Figure 15 is a side, semi-sectional view of the part shown in Figure 14, with modifications.

Figure 2 shows a hardened-steel adaptor 40. The adaptor 40 is generally of tubular form, and has an axially extending through-passage 42. The adaptor 40 is formed with an annular groove 44 around one end part of the adaptor 40 to receive engaging members of a quick- release device (not shown in Figure 2) . The other end of the adaptor 40 which engages an injector head has an internally and externally enlarged portion 48. The enlarged portion 48 extends to an injector-connection end 49 of the adaptor, which end is provided with, an internally screw-threaded section 50. A shoulder 52 is formed inwardly of the screw-threaded section 50, for holding a nozzle member in place when the adaptor 40 is in use. Between the enlarged portion 48 and the groove 44 there is an internally and externally tapering section 54. When in use the tapering section 54 provides space for a user's finger tips to enable the user to obtain a firm grip on such a quick-release device (not shown in Figure 2) . There is a sleeve 51 at the end 49 which extends beyond the screw-threaded section 50. The sleeve 51 embraces an end part of an injector head when the adaptor 40 is connected thereto. The sleeve 51 then

increases the resistance of the adaptor 40 to shearing relative to the injector.

A tapering orifice plate may be fitted inside the adaptor 40 in the tapering section 54 immediately downstream of a nozzle member when the adaptor 40 is in use.

Figure 3 illustrates the annular groove 44 of the adaptor 40 in greater detail. Thus, in cross- section, the groove has a flat sloping or slanting downstream side 56, a flat bottom 58, and an arcuate concave upstream side 60. The flat sloping side 56 is preferably at substantially 33 ^β to the main axis of the adaptor 40, to provide a relatively easy quick-fit and quick-release whilst at the same time providing an adequate retaining effect.

The adaptor 40, as illustrated in Figure 4, has a widened hexagonal cross-section along a part of its enlarged portion 48 to allow relatively easy tightening of the adaptor 40 on the injector head using a spanner or 'similar such tool, and also relatively easy clamping of the injector, by means of the adaptor 40, on to a test system when in use.

Figure 5 shows the adaptor 40 with a nozzle 20 and an injector head 10, both of which have already been described with reference to Figures 1, la and lb.

When in use, the adaptor 40 is screwed on to the screw-threaded end 11 on the injector head 10, securing

- li ¬

the nozzle 20 in place inside the adaptor with its flanged end clamped between the shoulder 52 and the extremity of the attachment end of the injector head 10. To ensure a fluid-tight seal around the nozzle 20, an 0- ring seal (not shown) may be provided on the shoulder 52. The sleeve 51 embraces an end part of the injector head immediately adjacent to its screw threaded end 11. The thus assembled injector is illustrated in Figure 6, which further illustrates a generally U-shaped mounting structure 54 for use with the adaptor 40. The mounting structure 54 is held in position by means not shown in Figure 6. It is held with its arms 55 in a generally horizontal position, and has a lower circular hole 56 in a lower one of its arms. The upper edge of the structure 54 around the lower hole 56 has curved sides 58 to form a snug fit with a part of the adaptor 40 immediately below the widened part of the enlarged portion 48. The structure 54 also has a through-hole 60 in its upper arm which accommodates an upper portion of the adaptor 40, inhibiting lateral movement thereof.

Figure 7 shows a quick-release device 61 which is provided at one end of a line 62. The device 61 has a generally tubular body 63 which is open at its end further from the line 62 to receive the quick-release end of the adaptor 40. Radially extending through holes 64 (only one of which is shown in Figure 7) are provided adjacent to the open end of the body 63, in which are

located respective ball bearings 65. Thus the ball bearings 65 are free to move in a radial direction, but are inhibited from movement in an axial direction. A sleeve 66 surrounds the body 63 and the ball bearings 65, and is slidable in an axial direction. The sleeve 66 is urged towards the adaptor 40 by a helical spring 68, over the ball bearings 65. The latter engage the annular groove 44 of the adaptor 40. The quick release device 61 further has an O-ring 70 made of for example a plastics material to obtain a fluid-tight seal between the adaptor 40 and the device 61. A steel wire circlip 72 acts as a retainer when assembling the sleeve 66 onto the body 63.

The line 62 may be readily released from the adaptor 40 by the user grasping the sleeve 66, the tapering 54 of the adaptor 40 accommodating the user's finger tips for this purpose, whereupon the sleeve 66 is slid away from the adaptor 40, against the restoring force of the spring 68, clear of the ball bearings 65. Further movement of the device 61 away from the adaptor 40 causes the ball bearings 65 to ride up the sloping side 56 of the groove 44, out of engagement therewith.

The line 62 may be readily re-connected by the reverse process.

The illustrated adaptor 40 may be constructed to enable it to withstand an internal pressure of substantially 2000psi(140 bar).

Figures 8 and 8a show an injector head 10 for a

- 13 -

fuel-injection engine. The injector head 10 is formed with a flange 80, holes 82 in the flange 80 and securing means in the form of bolts 84 (only one of which is shown in Figure 8) . The bolts 84 are normally used to secure the injector head 10 to an engine casing. In Figure 8 an adaptor 40 is provided which has a matching flange 86 at an upper end thereof, with threaded holes 87 in registration with the holes 82 in the flange 80 of the injector head 10, so that the adaptor 40 can be clamped via the bolts 84 to the injection head 10. Alternatively threaded studs and nuts can be used as securing means. Both the injector head 10 and the adaptor 40 are longer than those of Figure 6. In Figure 8 a separate support seal 88 is shown which is inside the body of the adaptor 40 to act as a seat for the nozzle 20 without the need for any adaptation thereto. This is desirable because such adaptation might involve disturbance to a nozzle holding piece 90 of the injector 10, which in turn could result in ingress of dirt particles or other onta ination of the injector in a workshop environment. In Figures 9 and 9b, a modified injector head 10 for a fuel-injection engine is shown. The injector head 10 has a generally cylindrical form with annular O-ring grooves 91 formed around the axis of the injector, which normally match with cylindrical galleries in an engine's cylinder head when the injector is in place in a fuel- injection engine. An adaptor 40 surrounds the injection

head 10. Clamping means for securing the injector head 10 in the adaptor 40 are provided in the form of a slot 92 in the top of the adaptor 40, a clamping plate 93 positioned in the slot 92 and a screw bolt 94 which extends through a central screw threaded hole 95 in the plate 92 and is in screw-threaded engagement therewith, so that relative rotation between the bolt 94 and the plate 93 firmly clamps the injector head 10 in the adaptor 40. This modified injector and adaptor arrangement also has a separate seal 88 similar to that illustrated in Figure 8. The grooves 91 in the outer surface of the injector head 10 are provided with O-ring seals 96 made for example of plastics material to provide fluid-tight seals. In Figures 10 and 10a a fuel-injection engine injector head 10 referred to as a ^•• pencil" is illustrated. -The injector head 10 in this embodiment has a long cylindrical nozzle-holding section 100 and an upper section 102 of cylindrical form, which has an indented pocket 104 machined into it. A separate clamp screw 106 with a lug 108 that exerts clamping forces onto the bottom face of the machined pocket 104 is provided. An adaptor 40 has a relatively long enlarged section 48 to accommodate the section 100 of the injector head 10. The adaptor 40 has a flange 110 at its upper end, the flange 110 being provided with a screw-threaded hole 112 to mount the clamp screw 106, and thus to provide a face

to resist reaction forces to those applied to the injector. The adaptor 40 is equipped with an annular 0- ring seal 112 made of a plastic material at the nozzle end to provide a fluid-tight seal. It will be appreciated from the modified constructions shown in Figures 8 to 10, that the adaptor can be secured to the injector other than by way of that part of the injector which corresponds to the screw- threaded end 11 engaged by the nut 22, for example, shown in Figure 1. In such a modified construction, the adaptor may be provided with pockets, or circular grooves, recesses or other forms which match the grooves 91 of the injector head shown in Figure 9 and provide locations for sealing means such as the O-ring seals 96. Numerous variations and modifications to ^' the illustrated adaptors will occur to a reader of ordinary skill in the art without taking the modified construction outside the scope of the present specification. For example the nozzle might be an integral part of the adaptor.

The injector head 10 shown in Figure 11 is provided with a spray diffuser or spray damper 120. The spray diffuser 120 has a generally circular cross- section, has a hollow interior 122 and is held on a nozzle retainer 124 at the end of an injector by an internal screw thread section 126 at its injector attachment end, engaging an external screwthread section

127 on the nozzle retainer 124. The spray diffuser 120 contains the end of a nozzle 128 in the screw-threaded section 126. At the end of the hollow interior 122 away from the nozzle 128, there are holes 130 in the wall of the spray diffuser 120. The holes 130 are immediately above a flange 132 on the outside of the spray diffuser 120. The flange 132 is equipped with a sleeve 134 which extends upwardly from flange 132 towards the injector. The end 136 of the spray diffuser away from the injector has a cone shape, tapering downwardly towards a pointed tip of the diffuser. A short section 137 of the diffuser between the flange 132 and the cone shape 136 provides locking flats to enable the diffuser to be fitted tightly on the injector head. A measuring graduate 139 is placed under the cone-shaped end 134.

When in use the nozzle 128 sprays the test-oil into the interior 122 of the spray diffuser 120 in a plume 138. The oil then falls to the bottom of the spray diffuser 120 and flows out through the holes 130 and up over the sleeve 134. It then runs down the outside of the spray diffuser and falls from the pointed tip of the cone-shaped end 134 in a narrow stream 140 into the measuring graduate 139.

The spray diffuser 120 is thus used with "open chamber" oil-pump test benches and has the advantage that it reduces the energy of the nozzle spray in a manner that keeps turbulence to a very low level. Also, less

air is absorbed by the oil thus reducing froth and making for more accurate volume readings of oil pumped out of the injector.

Figure 12 shows the injector head 10 of Figure 11, used in an open chamber system in that Figure 11, but here provided with an adaptor 40 fitted over the end of the injector head 10 for a closed chamber system. An enlarged portion 142 of the adaptor 40 fits round the nozzle retainer 124. The adaptor 40 is held to the injector head 10 by an internal screw threaded section

144 immediately below the enlarged portion 142, which screws on to the screw threaded section 127 on the nozzle retainer 124. The adaptor 40 is equipped with an O-ring seal 146 to form a seal between the adaptor and the injector without any need to disturb the nozzle retainer

124.

A hollow portion 148 of the adaptor next to the nozzle acts in a similar manner to the hollow interior on the spray diffuser 120, and the test-oil flows down and out of the quick-release end of the adaptor without the possibility of spillage which can occur with the open chamber system. The adaptor 40 thus enables air to diffuse out of the test-oil.

It will be appreciated that a closed chamber - system referred to herein is one in which, as is the case with the apparatus illustrated in Figures 1 to 10, and with reference to Figure 12, injected test-oil is taken

to a measurement system through pipe-work which is closed to atmospheric pressure. Damping of the spray pressure from the injector is, in a closed chamber system, provided by compliant or semi-compliant sections of pipe- work and by the clamping effect of the relatively large volumes of fluid within the pipes themselves.

Thus it will be appreciated that the adaptor 40 shown in Figure 12 enables an injector hitherto used in an open chamber system, to be used in a closed chamber system. To achieve this hitherto, it was difficult to seal the threaded ends of the injectors for a closed chamber system, after the spray diffuser 120 had been removed. The adaptor 40 shown in Figure 12 substantially overcomes this difficulty, and enables owners of open chamber system test benches and closed chamber system benches, in the same workshop, to interchange injectors between these different benches relatively easily.

The test injectors fitted with the adaptor are normally mounted in racks for attachment to diesel pumps. It has been found that if the test injectors are mounted vertically then it is difficult to engineer the system so as to collect the normal leakage from the injector 102 and the manual pressure release leakage 103

(see Figure 13) . Also, tests have proved it to be ergonomically better to mount the injectors at an angle rather than vertically for ease of installation.

These problems are obviated with the system

outlined in Figure 13. The injector and adaptor assembly along with the quick-release assembly 111 are both mounted in a U-shaped housing 104. All these components are mounted into a tray 101 which allows any excess leaked fuel to be collected and taken away via a pipe connection 107. The test-oil flow from the injector passes through a filter 112, via a pipe 105 to a flow measuring system 106. Tests have shown that ergonomically a 30 degree angle from the horizontal for the injector, with the nozzle end thereof uppermost, appears to be optimum. This orientation also has the added advantage of readily providing means of naturally self purging air from the system.

Figure 14 shows more detail of this arrangement with a bore 113 being machined in one arm of the U-shaped housing 104, to receive a flanged packing cylinder 108 which in turn receives the adaptor 116, and a screw- threaded bore 114 in the other arm of the U-shaped housing 104, to receive the quick-release assembly 111. The respective axes of the bores 113 and 114 are co- linear. This ensures accurate alignment of the adaptor with the quick-release assembly 111. The flanged cylinder 108 fits accurately in the bore 113. This component is made of a plastic material in order to offer some degree of vibration damping. It is held in place by a pin 109.

The advantages of this construction are as follows:-

1) it provides an accurate means of aligning and locating the injector while moving the sleeve 166 to engage the quick-release assembly 111;

2) the relatively high torque involved in tightening the high pressure pipe thread 113 on the injector is partially achieved through the support structure 104 and not solely through the quick-release assembly 111; and

3) for large output nozzles significant heat is produced at the nozzle and therefore the flanged cylinder 108 provides a means of partially thermally insulating the injector from the rest of the support structure 104.

It should be noted that a thread form 110 has been machined on the adaptor 116 in order to fit the diffuser described in Figure 11.

Figure 15 shows a possible design using O-rings 119 located in the flanged cylinder 108 to increase the amount of vibration damping. This is particularly important in reducing the amount of noise and vibration transmitted to the rest of the structure. It is held in place by a screw 118. The material of the flanged cylinder 108 remains the same as that shown in Figure 14.