US2833571A

US2833571A - Sealing glands

Info

Publication number: US2833571A
Application number: US362343A
Authority: US
Inventors: Richards Arthur Bruc Gillespie
Original assignee: BICC PLC
Current assignee: Balfour Beatty PLC
Priority date: 1952-06-26
Filing date: 1953-06-17
Publication date: 1958-05-06
Anticipated expiration: 1975-05-06

Description

May 6, 1958 A. B.`F. G. lcHARDsoN SEALING GLANDS 6 Sheets-Sheet 1 Filed June 17, 1953 May 5, 1958 A. B. F. G. RICHARDSON 2,833,571

SEALING GLQANDS Filed June 1'7, 1953 6 Sheets-Sheet 2 May 6, 1958 B. F. G. RICHARDSQN 2,833,571

SEALING GLANDS Filed June 17, 1953 6 Sheets-Sheet 3 B @zw/YK# A ttorneys May 6, 1958 SEALING GLANDS 6 Sheets-Sheet 4 Filed vJune 17, 1953 May 6, 1958 A. B. F. G. RICHARDSON K 2,833,571

SEALING GLANDS l A Inventor rurmce 1'" rafael' Gilesfie Riche rdson @zal y M4 Attorneys May 6, 1958 A. B.IYF. G. RICHARDSON 2,833,571

SEALING GLANDS Filed June 17, 1953 e sheets-sheet e ICZ ' l I 3 /O 5 Inventor ryrrafaser ll'lles/azic/hzrllson /f' Attorneys United States Patent SEALING GLANDS Arthur Bruce Fraser Gillespie Richardson, Leigh, England, assignor to British Insulated Callenders Cables Limited, London, England, a British company Application June 17, 1953, Serial No. 362,343 Claims priority, application Great Britain June 26, 1952 8 Claims. (Cl. 286-16) This invention relates to means for preventing or limiting the escape of lluid through an outlet in the wall of a vessel containing fluid under super-atmospheric pressure during the passage of a cable through the outlet. Here and when used without qualification hereinafter in this specilcation .and ini the claims forming a part thereof the term electric cable means an insulated electric wi-re or an insulated electric cable. Such escape of uid can be prevented or substantially limited by the use of a sealing gland designed to suit the cross-sectional shape and size of the travelling cable. In some cases however it is necessary to attach the leading end of the cable to be led out of the vessel to a lead wire by which the cable can be hauled through the vessel until the cable itself can be engaged by the hauling device. Where, as will often bethe case, there is considerable dilerence between the cross-section of the lead wire and that of the cable the sealing gland remains ineffective until theY cable reaches it. This may render it impossible to obtain in the vessel the conditions required for tthe effective treatment of the cable until the cable is emerging fromv the vessel, with the result that alength of the cable leaves the vessel inan untreated or incompletely treated condition. Such is the case with continuous processes for the vulcanisation of rubber covered cables of large size, for so much steam or other vulcanising fluid under superatmospheric pressure will escape through the clearance betweenthe outlet'gland of the customary cooling tube ut the outlet end of the vulcanising chamber and the lead wire by'which the leading end of the cable is hauled through the chamber and cooling tube, that it becomesv very diicult to obtain the required vulcanising conditions until the cable has entered the outlet gland.

kln accordance with the present invention we over-` come the difficulties referred to above and prevent or` limitthe escapel of il'uid from the vulcanising chamber whilst thecable to betreated'is being hauled through the' chamber by a lead wire of smaller vcross-section, b y ar4 ranging on the exit side of the main outlet sealing gland an auxiliary sealing gland designed to lit the lead 'wire and providing for the automaticl removal of this auxiliary gland on the approach of the leading end` of the cable,

that is to say, as the leading end gets near the outlet.

The auxiliary gland` may be housed in the outer end` of a tubular-member which may or may not be formed` of twogparts one ofV which houses the main gland and the otherrforms a tubular extension of thernain gland' In either case it. will be a sliding lit in itsk housing. housing in'which it is retained by latching means which are automatically released on the approach of the leading end of thel cable'. On release of the latching means the pressure of the tluid in the vulcanising chamber will expelA the auxiliary gland v'from its housing and leave the wayclear Lfor the passage ofthe cable emerging from theA main. gland.. v

i The. auxiliary gland'm Y be divided-longitudinally into two parts making joint with one another, preferably on `ice a diametral plane of the gland or it may consist of more than two parts making joints preferably in planes radial to the axis of the gland, so that, on being expelled from the housing, the parts of the gland either freely fall away lfrom the lead wire or are guided away by outwardly movable supports to which they are attached.

Instead of being housed in the outer end of a tubular member housing the main gland, the auxiliary gland may be positioned in front of and held against such member or an extension thereofto make joint between the adjoining end faces of the gland and the memberl or the extension until released automatically on the approach of the leading end of the cable. In this case also, the auxiliary gland may be split into two or more parts which must not only be held against the pressure exerted by the fluid in the vulcanising chamber but also be held laterally. This may be done by mounting each part on a pivoted arm swingable in a plane radial to the axis of the outlet glands and initially latched in position but on the approach of the cable released automatically to move the parts forwards and outwards from the outlet, thereby leaving it clear for the passage of the cable. e'

Automatic release of the latching or other means by which the auxiliary sealing gland is held in its operative position may be effected at the appropriate time in a number of ways. For instance, it'may be elected by the action of a cam whose movement is co-ordinated with the speed of travel of the lead wire through the outlet of the vulcanising chamber. Such co-ordination may be obtained by driving the cam in rotation through reduction gearing from the haul-on device by which movement is imparted to the lead wire.

The invention is particularly useful when applied to apparatus for the continuous vulcanising of rubber covered cables of, for instance, one inch or more in'diameter, where a lead wire of the same diameter as the cable is obviously impracticable, and examples ofreleasable auxiliary glands mounted on the exit ends of the main outlet glands of the usual pressurised coolingV tubes at the delivery ends of the vulcanising tubes of such apparatus Will now be described with the aid of the accompanying drawings, wherein- Figure 1 is a side view, partly in elevation and partly in section, showing an example of an automatically removable auxiliary gland mounted at the exit end of the outlet gland of a pressurised cooling tube, f

Figure 2 is a fragmental side view, partly in eleva# tion and partly in section and drawn to a larger scale than Figure l, showing the auxiliary gland and its automatic release mechanism more clearly, v

Figure 3 is a fragmental view showing a modiedform of the auxiliary gland shown in Figure l,

Figure 4 is a side View partly in elevation and partly in section showing a further example of an auxiliary gland mounted at the outlet end of a pressurised cooling tube and automatic release means therefor, Y

Figure 5 is a section on the line V-V in Figure 4 but drawn to a larger scale and f Figure 6 is a side view, partly in elevation and partly in section but drawn to a larger scale, of a part of theY and partly in section and drawn to alarger scale than Figure l showing `a further modified form of the auxiliary gland and its automatic release mechanism.

The outlet end of the cooling tube 1, shown in Figures l and 2 of the drawings, forms a continuation of a vulcanising tube (not shown). During the starting up of the continuous vulcanising process the tube l will be freely incommunication with the vulcanising tube and hence lled with steam and water under pressure. It is fitted with a cold water sealing gland 2. This is the main `outlet gland and is of the form described with reference to and shown in Figure 4 of the specification of our prior application 122,194 andissued May 18, 1954, as Patent No. V2;678,839 except that in place of a detachable end wall which screws on they outer end of the `gland body to hold the rubber gland bushes 3 in place, we provide a tubular member 4 having an annular recess 5 in one end wall thereof which receives theouter end of the main gland body` 6 and secure the tubular member 4 to the main glandbody by a nut 7 madecaptive onthat body. The bore of the tubular member 4 is enlarged at its outer end to provide an annular step 8 to form a seating for an auxiliary glandn9 housed within the enlarged part of the bore. The auxiliary gland is in two parts which mala: joint in avertical diametral plane and has a smooth bore of a` diameter corresponding to that of the lead wire le by which the cable 11 is hauled into and through the vul canising and cooling tubes and on to a capstan 12 in advanceV of thecooling tube 1.` From the capstan the lead wire and cable pass to a take-up reel (not shown).

The wall of the bore` of the auxiliary gland 9 is litted with rubber sealing rings 13 also split in thesame diametral plane.` These are held in undercut annular grooves. A sealing ring 14` is also located in an undercut circumferential groove in the peripheral surface on the gland. It has -anundercut groove 15 in its circumferential surface-,toassist'it to make a steam-tight joint with the wall off'the tubular member 4 supporting the auxiliary gland.

The twoparts of the auxiliary gland 9 are held in place by a projection 16 on the free end of one `arm of a bellcrank lever 17 pivotallysecured at 18 to the tubular support. member 4 so` as to swing in a plane radial to the axis of the gland.` This projectionI or latch 16 passes through an opening19 in the wall of the tubular support member `4` and yenters `a recess 20 in the neighbouring surface ofQthe, two-part gland 9 to hold both parts on the seating 8; The latch16 is held in the recess by pressure exerted by a helical spring 21 placed between the other arm `of the lever 17 and an adjustable abutment 22 mounted ont atixed arm 23` projecting from the auxiliary gland support tube;4. Between the two arms of the bellcrank lever isI a cam 24irotatable about an axis parallel to the pivot axis of the bell crank; VThe cam 24 is designed to'engage the curved-overfencl 25 `of the second arm of the ball crank lever and to rotate the lever to an extent to` withdraw the latch 16 from engagement with the two parts of the auxiliary gland 9 and so permit them to be; expelled from the support` tube 4 by pressure of steam and4 Water. t

The cam24;is removably mounted on a cam shaft 26 which as is more clearlytshown in Figure 7 is driven at a speed proportional to the speed of travel of the cable through the vulcanising and cooling tubes by a drive S1 taken from the4 driving shaft 27 of the haul-oil capstan 12. To allow for thermal expansion and contraction of the vulcanising and cooling tubes the` cam shaft bearings are mounted on a support 28 which is slidable in the direction of length of the cooling tube 1 and is coupled to the outlet end of the cooling tube so as to move with the main and auxiliary sealing` glands. For the same reason, the nal drive to thecam shaft 26 is a chain drive 29 with a jockey pulley 30 to take up slack in the chain as the cooling tube moves endwise due to expansion ol the vulcanising tube. A positive type of locking clutch 82 of `any convenient form is provided in the drive to the=cam shaft 26ito enable the cam 24 to be set to trip at the appropriate moment. This clutch is preferably introduced between chain `wheel 31 and the camshaft 26. y Between the end of the auxiliary gland support tube 4 and the `point at which, `iirst the lead wire 10` and then the cable 11,V run on to the haul-ott drum 12 is located V4 an apertured guard member 32 which arrests the forward movement of the parts of the auxiliary gland 9 as they are blown out of the support tube 4 and prevents them from fouling the haul-off drum.

lf required, the main and auxiliary sealing glands 2 and 9 and their supports and the haul-oft drum 12, can bc enclosed in a common casing 33 (shown without its hinged front cover) serving to collect such steam or water as may escape during starting up and normal running of the apparatus. The casing is provided with an outlet 34 for the cable running olf the bottom of the capstan. It is also furnished with a steam vent 35 and a drain 36. Access to the auxiliary gland Vfor resetting purposes is through a trap door 37. p

in the arrangement shown in Figure 3 the auxiliary gland 39 is in two parts which make joint with one another on a horizontal diametral plane but instead of making a steam-tight joint with the cylindrical wall of the tubular kmember 4 as shown in Figure 2, the auxiliary gland carries on its inner end face a sealing ring 40 which bears upon the end face of the member 4. Each half of the gland is mounted on one end of a centrally pivoted arm 41 and held in place by a trigger 42 which supports the opposite end of the arm 41 against the thrust of a spring 43. Each trigger is held in the latching position by one of a pair of stepped cams 44 driven in opposite directions from a capstan or other wheel round which the lead wire 10 passes as it leaves the main and auxiliary sealing glands of the cooling tube. As the steps of the two cams leave the horizontal arms of the triggers, the tail ends of the arms 41 are released and the other ends carrying the halves of the gland 39 `swing in a plane radial to the axis of the gland and each moves its half of the auxiliary gland forwards and outwards from the outlet of the main gland, thereby leaving it clear for the passage of the cable attached to the tail end of the lead wire 10. t

Fig. 8 shows means comprising outwardly movable supports 142 for the two parts of an auxiliary sealing gland of the form shown in Fig. 2. As the two parts are expelled from their housing they arev guided-away from the path of the cable by the two arms to which they are attached. This additional figure shows `the two parts of the auxiliary gland carrying supporting rods which are slidable `in a direction parallel to the movement of the cable in the ends of their respective supporting arms which are spring loaded outwardly by springs 143 but are held together by catches 144 which are triggered by the auxiliary gland parts when they are expelled from their housing.

In the arrangement shown in Figures 4, 5 and 6 auto` matic release of the auxiliary gland 49 is effected by a hydraulically operated relay 45 controlled by a valve 46 actuated by a ratchet gear driven by a return pulley 47 round which the lead wire 10 and its cable pass in succession on their way to a cooling trough 48 and a take-up reel (not shown).

From Figure 5 it will be seen that the relay 45 comprises a hydraulic cylinder 50 extending tangentially downwards from the cylindrical support tube 51 in which the twohalves 52 and 52' of the auxiliary gland 49 fit. These halves resemble those of the auxiliary gland 9 described with reference to Figure 2 but make joints in a horizontal diametral plane and have in their external surface a circumferential groove 53 the walls of which are engaged by a part of the circumferential surface of a bolt 54 slidablel in a cylindrical housing 55 in the wall of the support tube 51 housing the part 52, 52'. The tail end 57 of this bolt is of reduced diameter and carries at its extremity a piston 58 which works in the cylinder 50. Between theupper end wall 59 of the cylinder and the upper face of the piston is a compression spring 60.'

On theadmission of uid under pressure, through the inlet 61 in the cylinder cover 62, to the underside of the piston 58, the latteris forced upwards against the action v than onecam to the return pulley.

. Y of the spring 60 to a position inwhich the` head 'ofthe bolt is clear of the wallsof the .groove 53 in' the periphery of 4the auxiliary gland, as shown inbroken lines at 54. 'I'his releases both halves of the auxiliary gland 49 which are ejected from their s upporttube by the pressure of steam andlwater'in the cooling tube. i e

The valve 46 controlling the'supply of liuid under pressure to the relay 45 is shown in Figure 6. ',It comprises a balanced piston 63 workingin a cylinder 64y carried by a bracket 65 mounted on the inside of an end wall of a casing 66 enclosing the main and auxiliary outlet glands 2 and 49 respectively, and Ithe' return pulley 47 which itself forms the central part of one sidek wall of` the casing, as will be clear from Figure 4. The piston 63 is spring loaded by a compression spring 67 in the direction necessary to place the outlet 68, which is connected to the relayrcylinder 50 (Figure 5) by a flexible tube 69 (Figure 4), in communication with the inlet 70 which is connected to a supply of uid lunder pressure. Normally the piston 63 is held depressed by a cam 71 so that its upper bearing part cuts oi the valve inlet from the outlet. The cam 71 is mounted on a cam shaft 72 which also carries a ratchet wheel 72 adapted to be4 actuated by a pawl 74 mountedfon a pawl arm 75 ,whose free end vis engaged once during each revolution of the return wheel 47 by acam surface 76 mounted` on theperiphery of the return wheel. The cam `71 is turned from an initial position (shown in Figure 6) through an angle of 220 to a tripping position in which lit releases theV piston .63 allowing the valve to open. .-Atthe same time a locking catch 77 carried on the upper end of the piston 63 holds the return spring arm 78 of the ratchet gear inla raised position such that further engagement of the arm-v 75 `with the cam 76 on the return wheel is impossible vruntilthe cam 71 has been reset by hand by disengagingthe spring locking detent 79 and rocking the ratchet lever 75 until the cam returns to its original position. The number of complete revolutions of the return wheel 47 required to release the auxiliary gland, the ejected parts of which are arrested by a rubber faced buier 80 (Figure 4), will depend upon the angular movement of the ratchet arm per revolution. This may be varied within limits by varying the size or shape of the cam 76 and/or by iitting more In the example illustrated the valve operates after 22 revolutions of the return wheel.

It will be appreciated that in place of the cam actuated ratchet drive, described with reference to Figures 4-6, a reduction gear of any suitable form may be used to drive the cam 71 at a speed proportional to that of the wheel 47.

Assuming that it is possible to form a sound starting end on the covering within a distance from the connection between the cable core and the lead wire equal to less than half of the cooling tube, we prefer to arrange for the cam to move into its tripping position as the connection between the lead wire and the cable core reaches a point half way along the cooling tube. This will ensure that the sheathed cable will be either in the gland between the vulcanising tube and the cooling tube or just inside the cooling tube when the cam operates to release the auxiliary gland. Thus there will be very little loss of steam and ample margin of safety in case release and expulsion of the parts of the auxiliary gland should be sluggish.

What I claim as my invention is:

1. Means for limiting the escape of uid under superatmospheric pressure from a vulcanising chamber whilst a cable is being hauled towards and then through a tubular member forming an outlet from the chamber by a lead wire of smaller cross-section than the cable, comprising said tubular member, a main outlet gland housed in said tubular member and designed to suit the crosssectional shape and size of the cable, an auxiliary gland designed to lit the lead wire and housed in the outer end of said tubular member, said auxiliary gland being a sliding t in said outer end and being divided longitudinally int'ofat least two parts which make joint with one an'-l other, latching means for retaining said'auxiliary gland in its housing, means for' withdrawing said latching means on the approach -of the leading end of the cable being hauled towards said tubular member, outwardly movable supports for said parts of said auxiliary glandy for guiding the released parts of said auxiliary gland'away from v cable and on the exit side of the main gland an auxiliary sealing gland designed to tit the lead wire, latching means outside and laterally displaced from the axis of the chamber for retaining the auxiliary gland in place and means comprising a cam outside and laterally displaced from the axis of the chamber, a wheel (outside said chamber) round which said lead wire passes and means for driving said cam from said wheel, for withdrawing said latching means and thereby releasing said auxiliary gland on the approach of the leading end of the cable.

3; Means for limiting the escape of fluid under superatmospheric pressure from a vulcanising chamber whilst a cabley is being hauled towards and then through an outlet in th'e chamber wall =by a lead wire of smaller crosssection than the cable, comprising a main outlet gland designed to suit the cross-sectional size and shape of the cable and on the exit side of the main gland an auxiliary sealing gland designed to t the lead wire, latching means for retaining the auxiliary gland in place, a hydraulic relay for withdrawing said latching means, a' valve coutrollin'g said relay and a cam whose movement is co-ordinated with the speed of travel of the lead Wire through the outlet, for actuating said valve whereby to operate said relay to withdraw said latching means and release the auxiliary gland on the approach of the leading end of they cable.

4. Means for limiting the escape of lluid under superatmospheric pressure from a vulcanising chamber whilst a cable is 'being hauled towards and then through an outlet in the chamber wall by a lead wire of smaller cross-section than the cable, comprising a main outlet gland designed to suit the cross-sectional size and shape of the cable and on the exit side of the main gland an auxiliary sealing gland designed to flt the lead Wire, latching means for retaining the auxiliary gland in place, a hydraulic relay for withdrawing said latching means,Y a valve controlling said relay and a cam for actuating said valve, a pawl and ratchet gear for driving said cam c'omprising a spring controlled pawl arm, a wheel round which the lead wire passes, a cam surface carried by said wheel for periodically engaging said pawl arm whereby to oscillate it and to cause said cam to actuate said valve and thereby operate said relay and effect withdrawal of said latching means and release of said auxiliary gland on the approach of the leading end of the cable.

5. Means for limiting the escape of liuid under superatmospheric pressure from a vulcanising chamber whilst a cable is being hauled toward and then through an outlet in the chamber wall by a lead wire of smaller crosssection than the cable, comprising a main outlet gland designed to suit the cross-sectional size and shape of the cable and on the exit side of the main gland an auxiliary sealing gland designed to tit the lead wire, latchingmeans outside and laterally displaced from the axis of the chamber for retaining the auxiliary gland in place and a rotary cam outside and laterally displaced from the axis of the chamber and means separate from but co-ordinated with the feed of the cable through the chamber for driving said cam in rotation at a speed proportional 7 .to the` speed of advance of the leadingend of said cable through said vulcanising chamber whereby to cause said cam to withdraw said latching means and thereby release the` auxiliary gland on lthe approach of the leading end of the cable.

J6. A' continuous vulcanising machine for the manufacture of rubber covered cable comprising a vulcanising chamber having means for limiting the escape of fluid under superatmospheric pressure from the chamber whilst the cable is being hauled through an outlet in the chamber wall by a lead wire of smaller cross-section than 'the rubber covered cable, said means comprising a mainoutlet gland designed to suit the cross-sectional shape and size of the cable and on the exit side of the main gland an auxiliary sealing gland designed to t the lead wire, latching means for retaining the auxiliary gland in place, and means comprising `a cam and means separate from` but co-ordinated with the travel of the lead wirethrough the chamber, for driving said cam, for withdrawing 'the latchin'g means before the leadingfend of said cable reaches said main outlet gland, said latching means' and said cam being outside the chamber and laterally displaced from the axis of the chamber.

7. Means for limiting the escape of iluid under superatmospheric pressure from a vul'canisingy chamber whilst a cable is being hauled towards and then through an outlet inthe chamber wall by a lead wire of smaller crossscction than the cable, comprising a main outlet `gland designed to suit the cross-sectional size and shape of the cable and on the exit side `of 'the main gland an auxiliary sealinggland designed to fit the lead wire, latching means outside and laterally displaced from the axis of the cha'mber for retaining the auxiliary gland in place and a cam outside and laterally displaced from the ax-is of the cham- .ber and means separatefrom but co-ordinated with the feed ofthe cable through the chamber for driving said cam at aspeed proportional t'o the speed of advance of the `leading end of ysaid cable through said vulcanising chamber towards said main outlet gland whereby to cause said camjto withdraw said -latching means and release 'theauxiliary .glandbe'fore the leading 'end of saidcable reaches said main outlet gland. i

8. Means for limiting the escape of uid under Superf atmospheric pressure from a vulcanising chamber whilst a cable is being hauled towards and then through an outlet inthe chamber wall by a lead wire of smaller crosssection than the cable, comprising a main outlet gland designed to suit the cross-sectional size and shape of the cable and on the exit side of the main gland an auxiliary sealing gland designed 'to t the lead wire, latching means outside and laterally displaced from the axis of the chamber for `retaining the auxiliary gland in place, a cam outside and laterally displaced from the axis of the chamber for controlling the release 'of said vlatching means, said cam being rotatable from a rst position which maintains' said latching means in yits operative position to a position in which it releases Asaid latching means, and means separate lfrom but coordinated with Vthe feed of the cable through "the chamber for rotating said cam from 'its first position "into its release position as the leading end ofsaid cable travels 'forward through a prede termined distance towards the main outlet gland.

Referens-cidin-rhe sie af this paient f UNITED STATES PATENTS yRichardson `et al May '18, 1954