US2553619A - Contractible sleeve for tube fittings - Google Patents

Description

May 22, 1951 G. V. WOODLING CONTRACTIBLE SLEEVE FOR TUBE FITTINGS Filed Dec. 7, 1949 FIG.

I? k 28 6 w $7 A W ii INVENTOR.

Patented May 22, 1951 UNETED STATES TENT OFFICE CGNTRACTIBLE SLEEVE FOR TUBE FITTINGS 3 Claims. 1

My invention relates to tube couplings of th non-flare type and in particular to a contractible sleeve for engaging the tube or insertable member.

An object of the invention is to provide a contractible sleeve having the combination of an internal rib and a stepped shoulder for gripping the tube or the insertable member.

Another object of the invention is to provide a sleeve with a contractible ring portion having an internal annular rib at the leading end thereof and having a minimum wall section next adjacent the rearward side of the rib with the minimum wall section terminating in a stepped shoulder.

Another object of the invention is to provide a sleeve with a contractible ring portion having an internal annular rib at the leading end thereof and having a minimum wall section next adjacent the rearward side of the rib with the minimum wall section terminating in a laterally e:-:-

. tending side wall having an annular-cutting edge at its inner end.

tending side wall constituting a first side of a second rib in which the second rib has the second side meeting with the first side to define a substantially V-shaped second rib.

Another object of the invention is to provide a sleeve with a contractible ring portion having at least two cutting edges of different design for biting the tube or insertable member.

Another object of my invention is to eliminate an abutment shoulder in the coupling body against which the end of the tube may abut, whereby the tube may move longitudinally with the sleeve as the sleeve contractibly engages the tube.

Another object of my invention is to prevent the sleeve from shearing or plowing up an annular ridge or shoulder of appreciable size around the tube in advance of the internal and spaced cutting edges of the sleeve by permitting the tube spaced from each other at a distance which is less than the distance that the sleeve is pressed into an internal annular cam surface of a connection body, taken in combination with. a slow taper in the connection body into which the end of the tube may wedgingly engage and move therea-long, so that the second annular cutting edge does not bite into the region of the insertable member where the first annular cutting edge bites.

Other objects and a fuller understanding of my invention may be had by referring to the f01- lowing description and claims, taken in combination with the accompanying drawing, in which:

Figure 1 is an enlarged side view of a tube coupling embodying the features of my invention, the upper part being shown in section to illustrate the relationship of the parts prior to the time that the nut is tightened, the View being approximately 5 times scale for a inch tube;

Figure'2 is a fragmentary view of Figure 1 and shows the relationship of the parts after thenut is tightened, the view being approximately 10 times scale for a /2 inch tube;

Figure 3 is a cross-sectional view taken along the line 3-3 of Figure 1, and illustrates the disposition of the rearwardly extending segmental fingers which grippingly engage the tube when the nut is tightened;

Figure 4 is a fragmentary view similar to Figure 1 with a modified sleeve in that the stepped shoulder has been replaced by a second substantially V-shaped rib, the view being approximately 10 times scale for a inch tube;

Figure 5 is a fragmentary view similar to Figure 2 with the modified sleeve of Figure 4 cammed or deflected into the tube by the nut.

With reference to Figure 1 of the drawing, my invention comprises generally a coupling or connection body I I, a coupling nut i2, and a contractible sleeve l3 adapted to contractibly engage a tube or insertable member it.

The coupling body H is provided at its righthand end with male threads M which are adapted to be threadably engaged by female threads i5 provided in the nut 12 for pressing the sleeve into engagement with the tube. As illustrated, the coupling body i i is provided with a first entrance flare ii and a second entrance flare l3 which merges with the bore of the coupling body II to receive the tube. The second entrance flare l8 comprises a counterbore having an annular tapered wall section with a very small taper in the order of 2 or 6 degrees into which the end of the tube is wedgingly received to provide a. tube seal with the coupling body. The first entrance flare. H has an annular tapered wall section and extends outwardly toward the end It of the coupling body from the counterbore I8. The taper of the first entrance fiare ll may be in the order of 10 to 12 degrees measured with respect to the longitudinal axis of the tube.

The sleeve i3 has a bore 31 adapted to sur round the tube and comprises a continuous annular body 25 provided with rearward-1y extending segmental fingers 26 which grip the tube when the nut i2 is tightened. The sleeve is preferably constructed of steel capable of being quench hardenable throughout its entire mass and thereafter tempered or drawn back to a hardness value greater than that of the tube. I find that steel known as 4140, heat treated throughout its entire mass and tempered to a hardness value of approximately 30 to 50 Rockwell, is satisfactory for my sleeve, the hardness value being preferably in the neighborhood of 38 to 42 Rockwell.

In the manufacture of the sleeve, the fingers 25 are provided by making slots 2'! in the rearward. section thereof at annularly spaced intervals thereabout. In Figure 3, I show four slots but any other number may be used. The continuous annular body 25 has a first or leading end 28 and a second or rearward end 29. As illustrated, the end 29 constitutes the forward terminus for the slots H. The leading end 28 is, provided with an internal annular rib 30 which has two converging side walls 33 and 34 that meet to define an annular cutting edge 32 which is adapted to be embedded into the tube when the sleeve is pressed into the first entrance fiare I? by the nut l2. The side wall 33 constitutes a part of the first or leading end 23 of the sleeve and merges with an outer annular cam surface Ali! which constitutes the other part of the leading end of the sleeve. On the rearward side of the rib, the sleeve is provided with an internal relief bore having a longitudinally extending annular wall 35 which extends rearwardly from the rib 30 and terminating into a laterally or inwardly extending side wall 4| of a stepped shoulder 42. The laterally extending side wall 4i meets with the bore 3! of the sleeve to define a. substantially square cutting edge 53 to bite into the tube or insertable member H3. The relief bore is thus defined by the side 35 or the rib 36, the longitudinally extending annul r wall 35, and the laterally extending side wall M of the stepped shoulder 52. The radial depth of the rib 38 may L be approximately .010 of an inch and the radial depth of the laterally extending side wall 4| may be approximately .608 of an inch. The 1ongitudinal extending internal wall 35 defines, in combination with the external surface of the sleeve, a minimum or weakened wall section, whereby a hinge action is produced, so that the leading end section of the sleeve including the rib and the stepped shoulder 42 constitute a readily contractible ring portion which may be cammed or deflected inwardly against the tube notwithstanding the fact that the sleeve is constructed of quench hardenable steel. The thickess of the minimum wall section may be approximately .023 to .025 of an inch which is ap proximately twice as thick as the radial depth of the rib 33. The thickness or" the body portion of the sleeve immediately to the rear of the stepped shoulder may be approximately .033 of an inch, and experience shows that with the distance between the rib- 3t! and the stepped shoulder 62 being in the neighborhood of twice the maximum radial thickness of the sleeve, namely, approximately one-sixteenth of an inch, the contractible forward ring portion. including u O i) the rib 3B and the stepped shoulder 42 may be readily contractible against the tube with the: longitudinally extending annular wall 35 compressed against the tube. The intermediate part of the entire sleeve, that is; the rearward end of the continuous annular body 25 and the forward end of the segmental fingers 26 is enlarged to pro-- vide a tapered or cam shoulder 36 against which a cam shoulder 37 of the nut engages for pressing the contractible ring portion including the rib 353 and the stepped shoulder 32 of the sleeve into the first entrance flare I? and for contract-- ing the segmental fingers 26 about the tube.

In operation, as the sleeve is pressed forward by the tightening of the nut, the outer annular cam surface as of the sleeve forcibly engages the tapered wall section of the first entrance flare l'i and thereby produces a camming action which cams or deflects the leading end section of the sleeve against the tube. The camming action embeds the rib 3d and the stepped shoulder 42 into the tube which resists longitudinal pull. of the tube from the sleeve. Inasmuch as the end of the tube wedgingly fits within the second entrance flare is which is of a very slow taper, the tube is permitted to move along with the sleeve as the rib 3b and the stepped shoulder 42 becomes imbedded into the tube. Thus, the end of the tube may move from point 2! to point 22 of Figure 2 during the tightening of the nut, the point 2| being the place where the end of the tube becomes arrested when it is manually inserted therein by the operator. Since the tube may move with the sleeve, I prevent the sleeve from shearing or plowing up an annular ridge or shoulder of appreciable size around the tube in advance of the rib 3G or shoulder 42 of the sleeve. When the longitudinally extending surface 35 of the relief bore engages the tube, it functions to aid in limiting the degree to which the rib 3i and the stepped shoulder 42 may be embedded into the tube.

The maximum wall thickness of the sleeve which is immediately to the rear of the stepped shoulder 42 is sufficiently strong and resilient as to. present a substantially non-contractible portion, which gives a hit-home feeling or high torque value to the tightening of the nut. Both the readily contractible portion and the substantially non-contractible portion are disposed to be pressed against the internal annular cam surface of the first entrance flare ill in the order named. As the sleeve is initially pressed into the first entrance flare ll, the readily contractible portion, including the rib 36 and the stepped shoulder 42, cams or deflects inwardly against the tube for gripping the tube against longitudinal pull from the sleeve body 25. As the sleeve is further pressed into the entrance flare I1, the substantially non-contractible portion resists further inward contraction of the sleeve, the resisting action limiting the amount that the sleeve may be pressed into the entrance flare H, and thereby producing a hit-home feeling or high torque value to the tightening of the nut. The substantially non-contractible portion of the sleeve prevents the leading end or contractible portion from excessively collapsing or inwardly buckling the wall of the tube. As resistance to longitudinal pressing movement of the sleeve is encountered, the cam shoulder 31 of the nut presses against the cam shoulder 36 of the sleeve and contracts the segmental fingers 26 against the tube for giving support to the tube against vibration. The fingers are disposed to spring back from the tube when the nut is released or disengaged.

The engagement of the sleeve against the tube and against the entrance flare l'l provides the main seal against high fluid pressure, as distinguished from the tube or secondary seal af forded by the end of the tube wedgingly fitting into the slow tapered bore :8. Notwithstanding the fact that the tube or secondary seal may allow the escape of fiuid which is blocked or sealed by the main seal, yet the tube or secondary seal acts as a buffer to dampen high peak transient fluid shocks from eifectively reaching the main seal.

In my fitting, the tube and sleeve may be repeatedly disconnected from and re-connected to the coupling body. Upon each re-connection the sleeve re-seats itself for sealing purposes as there is a certain amount of small give or yielding to the substantially non-contractible portion and the entrance flare H, as well as to the tube [9. The hit home feeling which the operator senses upon the tightening of the nut for the initial installation or for the recoupling installations is definite enough to indicate to the operator to cease attempting to turn the nut on any farther.

In Figure 4, I show a modified sleeve in which the stepped shoulder 42 has been replaced by a second rib 46. The laterally or inwardly extending side 4| constitutes a first side of the second rib, which second rib has a second side wall 41 that meets with the first side 4! to define a substantially V-shaped rib with an inner annular cutting edge 48 to bite into the tube. The radial depth of the second rib 45 may be approximately .005 of an inch with approximately a 60 included cutting angle being the same as the included angle for the rib 39.

The rib 30 and the stepped shoulder 42 are spaced from each other approximately of an inch and this distance is less than the distance that the sleeve is pressed into the internal annular cam surface ll of the coupling body ll; namely, appproximately of an inch, when the nut is tightened substantially two turns which is the recommended practice in the trade. As the nut is tightened, the end of the tube wedgingly moves longitudinally into the slow taper of the second entrance flare [8, whereby the cutting edge 43 of the stepped shoulder 42 does not overtake and bite into the same region of the tube where the rib 3e bites, as it would otherwise do if the end of the tube were abutted against a shoulder in the coupling body which would prevent the tube from moving into the couplin body as the nut is tightened. The same condition holds true for the rib 38 and the second rib 46. The

movement of the end of the tube into the slow taper of the second entrance flare I! prevents the sleeve from shearing or plowing up an annular ridge or shoulder of an appreciable size around the tube in advance of the internal rib 30 as well as in advance of the stepped shoulder 42 or the second rib 45. The rib 3B merely penetrates the tube to make a groove therein without appreciably deforming the inner surface of the tube, the deformation being limited only to a few thousandths of an inch, being in the order of .010 of an inch or less, depending upon how tightly the nut is turned on, and is not so much as one might judge from viewing Figures 2 and 5 of the drawing which is approximately ten times scale for a one-half inch tube. The metal from the groove is not displaced forwardly to form an annular ridge-like shoulder. The sharp cutting 6 edge 43 of the stepped shoulder 42 and the second rib 46 also penetrates the tube without shearing up forward annular ridge-like shoulders. The distance between the cutting edge 32 of the rib 3 and the cutting edge 43 of the stepped shoulder 42 is greater than the length of the annular recessed wall 35, with the result that the metal of the tube therebetween is compacted or pressed in tight, as the rib 30 and the stepped shoulder 42 penetrate the tube. The same action holds true between the cutting edge 32 of the rib 3E! and the cutting edge 48 of the second rib 45 as the nut is tightened. In other words, the area between the rib 3E! and the stepped shoulder 42 or the second rib 46 gradually reduces as the cutting edges penetrate the tube.

As the nut is turned on substantially two turns, being the condition shown in Figures 2 and 5, it is noted that the portion of the bore 3| immediately in the rear of the cutting edge 43 of the stepped shoulder 42, being indicated by the reference character 38 is cammed inwardly against the tube to provide an additional fluid pressure seal therealong. The engagement between the bore portion 38 and the outside of the tube is one of tight compression and is not one where the outside side of the tube has been sheared or out. It is to be noted that the recessed annular surface 49 immediately to the rear of the second rib 46 likewise cams inwardly against the tube to make an additional fluid pressure seal and this engagement is also one of tight engagement.

The turning of the nut appreciably beyond two turns is met with an ever-increasing torque value or hit home feeling which tends to cause the operator to cease turning the nut any farther. The high or increasing torque value arises principally from the fact that the substantially noncontractible portion of the sleeve, being the maximum wall section behind the stepped shoulder 42 or behind the second rib 45, resists collapsing too far, although it has a certain amount of small give or resiliency. As the nut is turned on, the recessed annular wall 35 contracts about the tube and becomes in substantial alignment with the bore SI of the sleeve, or slightly therebeyond, at about which condition it begins to engage the tube and sets up resistance against excessive collapsing of the tube, the collapsing being limited to only a fewthousandths of an inch, being in the order of .016 of an inch or less, depending upon how tightly the nut is turned. Thus, in the anchored condition of the sleeve to the tube, the recessed annular wall 3.5 is substantially in alignment with the bore 3! of the sleeve, or slightly therebeyond, depending upon how tight the nut is turned.

The rib 39 as contrasted from the shoulder 42 or the second rib 46, bites into the tube and. forms a groove with a greater radial depth than the grooves formed by the shoulder 42 or the second rib 46. The grooves are made by radial embedding or penetration action rather than by a longitudinal shearing action, as would be the case if the sleeve moved longitudinally of the tube. The shearing action forms shoulders on the tube as distinguished from the side walls of the grooves formed in the tube by the present invention. The left-hand side Wall of the groove formed in the tube by the radial penetration of the shoulder 42 may not completely fill the outer corner of the shoulder against the recessed wall 35 as the tube may tend to barrel or neck in a slight amount, as the shoulder 42 penetrates the tube.

Although this invention has been described in 7 its preferred form with a certain degree of particularity, it is understood that the present disclosure of thepreierred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

I claim:

1. A contractible sleeve provided with a bore to receive an insertable member having a substantially cylindrical outer surface, said sleeve comprising a continuous annular body having at one end thereof a contractible ring portion, said contractible ring portion having on its inner surface an internal substantially V-shaped rib with first and second sides defining a first annular cutting edge to bite into the insertable member, said contractible ring portion on its inner face havin an inwardly extending wall positioned at a spaced distance from the rib and terminating in a sec-- ond, annular cutting edge to bite into the insertable member, both said annular cutting edges defining a diameter substantially the same as the bore of the sleeve, said contractible ring portion having an outer wall terminating in an outer cam surface merging with said first side of the rib, said outer cam surface and outer wall arranged to engage an internal annular cam surface of a connection body for camming the contractible ring portion againstthe insertable member, said contractible ring portion on its inner face having a longitudinally recessed annular wall defining a relief bore with a first end thereof meeting with the second side of the rib and with a second end thereof meeting with the inwardly extending wall, said longitudinally recessed annular wall on the inner face of the sleeve having a greater length than the second side of the rib and defining with the outer surface of the sleeve, a sleeve wall section of minimum thickness at a place substantially opposite where the outer cam surface and the outer wall of the ring portion engages with the annular cam surface of the connection body, the wall thickness of the contractible ring portion at said minimum section being sufiiciently thin to allow both said annular cutting edges to be cammed inwardly and bite the insertible member and to permit the recessed annular wall to be contracted against the insertable member.

2. A contractible sleeve provided with a core to receive an insertable member having a substantially cylindrical outer surface, said sleeve comprising a continous annular body having at one end thereof a contractibl ring portion, said contractible ring portion having on its inner surface an internal substantially V-shaped rib with first and second sides defining an annular cutting edge to bite into the insertable member, said contractible ring portion on its inner face having an extending wall positioned at a spaced distance from the rib and defining with said bore a stepped shoulder having an annular cutting edge to bite into the insertable member, said contractible ring portion having an outer wall terminating in an outer cam surface merging with said first side of the rib, said outer cam surface and outer wall arranged to engage an internal annular cam surface of a connection body for camming the contractible ring portion against the insertable member, said contractible ring portion on its inner face having a longitudinally recessed annular wall defining a relief bore with a first end thereof meeting with the second side of the rib and with a second end thereof meeting with the inwardly extending wall, said longitudinally recessed annular wall on the inner face of the sleeve having a greater length than the second side of the rib and defining with the outer surface of the sleeve, a sleeve wall section of minimum thickness at a place substantially opposite where the outer cam surface and the outer wall of the ring portion engages with the annular cam surface of the connection body, the wall thickness of the contractible ring portion at said minimum section being sufficiently thin to allow the rib and the stepped shoulder to be cammed inwardly and bite the insertible member and to permit the recessed annular wall to be contracted against the insertable member.

3. A contractible sleeve provided with a bore to receive an insertable member having a substantially cylindrical outer surface, said sleeve comprising a continuous annular body having at one end thereof a contractible ring portion, said contractible ring portion having on its inner surface a first internal substantially V-shaped rib with first and second sides defining a first cutting edge to bite into the insertable member, said contractible ring portion on its inner face having an inwardly extending side wall positioned at a spaced distance from the first rib and constituting a first side of a second rib having a second annular cutting edge to bite into the insertable member, both said annular cutting edges defining a diameter substantially the same as the bore of the sleeve, said second rib having a second side meeting with the first side to define a substantially V-shaped rib, said contractible ring portion having an outer wall terminating in an outer cam surface merging with said first side of the first rib, said outer cam surface and outer wall arranged to engage an internal annular cam surface of a connection body for camming the contractible ring portion against the insertable member, said contractible ring portion on its inner face having a longitudinally recessed annular wall defining a relief bore with a first end thereof meeting with the second side of the first rib and with a second end thereof meeting with the inwardly extending wall, said longitudinall recessed annular wall on the inner face of the sleeve having a greater length than the second side of the first rib and definin with the outer surface of the sleeve, a sleeve wall section of minimum thickness at a place substantially opposite where the outer cam surface and the outer wall of the ring portion engages with the annular cam surface of the connection body, the wall thickness of the contractible ring portion at said minimum section being sufiiciently thin to allow the ribs to be cammed inwardl and bite the insertible member and to permit the recessed annular wall to be contracted against the insertable member.

GEORGE V 'WOODL-ING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,211,856 Kreidel Aug. 20, 1940 2,452,278 Woodling Oct. 26, 1948 2,472,872 Woodling June 14, 1949

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