CONTROLLED PULLUP GAGEABLE PRESWAGE TOOL
A manual pre-swage tool is particularly useful for pre-setting the tube fitting ferrules onto the tube prior to the actual installation of the fitting components into the tube fitting body. The pre-swage tool is used by clamping in a vise, or other suitable means, in an open area where leverage and ease of use can be obtained. This new and improved design tool of the present disclosure incorporates a feature that prevents the ferrules from being over tightened thereby preventing damage to the tool or ferrules and also allowing the pre-swaged assembly to be fully compatible with what is called “stop collars” and “gap inspection gages” that are commonly used in the field to indicate proper pull up of the tube fitting when installed.
This application claims the priority benefit of U.S. provisional application Ser. No. 62/409,915, filed Oct. 19, 2016, the entire disclosure of which is expressly incorporated herein by reference.
This disclosure pertains to the use of a pre-swaging tool. More particularly, the invention pertains to a pre-swaging tool that pre-swages instrument-type tube fitting ferrules on to a tubing (tube) in an open, easily accessible area where leverage can be obtained to ease the force of pre-swaging the tube fitting ferrules onto the tubing and rotation of the wrench to tighten the nut is not hindered in any way.
Many of these types of fittings are installed in tight, cramped quarters. The tight quarters limit the turning of the tube fitting nut to small increments of tightening and also make it hard to develop the torque required to tighten the tube fitting nut.
These types of tools are in wide use but all of the current designs have serious drawbacks for the tool and also for the integrity of the tube fitting installation itself. The current designs that are used can allow the end user to over-tighten the tube fitting nut to an extent that can damage the tool and shorten it's useable tool life but more importantly, the over-tightening that is possible with the current design that is in use can make the reassembly of the pre-swaged ferrules into the tube fitting body to not be compatible with “stop collars” or “gap gages” which are both widely used in the industry.
Over-tightening the fitting nut on the currently available pre-swage tool can have several potential adverse or detrimental effects. For example, over-tightening the fitting nut can prevent the proper remake of the pre-swaged ferrules into the body when a “stop collar” is used which can potentially result in some cases with a high pressure gas leak. The stop collar can indicate a proper pull up when in fact the tube fitting was not remade properly after using the pre-swage tool.
It can also adversely affect the number of remakes that the pre-swaged ferrule assembly can have when installed into the fitting body when gap gages are not used.
SUMMARYA need exists for an improved arrangement that overcomes one or more of the above-noted problems.
Benefits and advantages of the present disclosure will become more apparent from reading and understanding the following detailed description.
In
As also shown in
Those familiar with the current pre-swage tool designs will appreciate the fact that with this new and improved design (any one of the embodiments of
The design can, as also shown, have a collar (similar in appearance to the stop collars used on the tube fitting assembly) that is permanently mounted but freely rotates until the proper pull up is achieved. This additional feature gives an additional fail safe against improper pull up (under-tightening) of the tube fitting components.
The precise configuration of the interface between the collar 240 and the body 202 may be altered in practice, although the illustrated preferred arrangement provides a radial shoulder 250 on the body 202 that cooperates with shoulder 252 that extends in an axial direction from the collar toward the radial shoulder (i.e., at an opposite end of the collar from surface 244). In a conventional pre-swage tool, the nut 132 can be over tightened as a result of the advancement of the nut relative to the body. In the present disclosure, this potential for over tightening cannot occur as a result of the abutment of the nut with the collar 244.
Installing the pre-swaged assembly into the tube fitting body is then accomplished the same as the current practice, i.e., tighten until an increase in torque is noted, then snug approximately ¼ turn, or until the nut abuts the “stop collar” when used. The pull up in the tube fitting body can also be checked for proper assembly using the “Gap Inspection Gage” when stop collars are not used and inspection for proper assembly is required.
This new and improved design which prevents over tightening of the nut can significantly reduce pull up errors in the pre-swaging operation and also significantly increase the useful life of the pre-swage tool itself. The added feature of the rotating collar will also help to reduce under-tightening which could lead to catastrophic failure of the tube fitting's holding ability.
According to the present disclosure, a new and improved manual pre-swage tool for use with the instrument type tube fitting is provided. The present disclosure changes the current design that all the major tube fitting manufacturers are currently selling to a tool that limits the maximum pull up that can be done to a predetermined amount. The currently available pre-swage tools are identical to the tube fitting which means that the user can over tighten the tube fitting components by any amount that they want. With the present disclosure, the possibility of over tightening is eliminated by physically making this impossible.
An alternative embodiment is shown
Still further,
More specifically, the pre-swage tool 600 has a body or housing 602 with a proximal, first end 604 and a distal, second end 606. A reduced dimension portion 608 includes an external threaded portion 610 and recess 612 is dimensioned to receive tubing (not shown for ease of illustration) therein. Nut 632 of the fitting 630 is received on the tubing, namely over the terminal end thereof, with the first and second ferrules 634, 636 received within the nut and on the external surface of the tubing. When the nut 632 is brought to finger tight engagement with the threaded portion 610 of the body, a predetermined gap 646 is defined between end face 642 of the nut and surface 644 of the collar 640. Rather than being press fit on to the body, the collar 640 is secured thereto by at least one retaining pin 680, and preferably multiple pins are generally equally-spaced about the perimeter of the collar for receipt in annulus 682 of the body. Further, bearings or seals 684 are provided at the axial interface between the collar 640 and the body 602 to allow relative rotation.
This variation of
The pre-swage tool 800 has a body or housing 802 with a proximal, first end 804 and a distal, second end 806. As is evident in
By controlling the pull up on the pre-swage tool to the required amount, all pull ups done using the new design pre-swage tool can now be compatible with the stop collars and gap type gages that are used to verify proper pull up in the final assembly.
It is also noted that the customer cannot use any of the manual pre-swage tools that are currently available if the customer intends to use any type of stop collar or gap gage to verify final assembly. This is due to the fact the user can over tighten the tube fitting components using the pre-swage tool which makes the use of stop collars or gap gages useless.
In accordance with the present invention, a manual pre-swage tool is shown that facilitates the proper pre-swaging of the tube fitting components by limiting the amount of pull up to what is required.
According to the invention, the amount of pre-swage done to the tube fitting ferrules is limited to the proper recommendation of 1¼ turns past the finger tight position, (or slightly biased just short of the recommended pull up) and makes the pre-swaged assembly compatible with all current types of installation requirements.
This includes systems that use what is commonly called “stop collars” which limit the pull up in the fitting body when a pre-swage tool is not used along with installations that require the tube fitting pull up to be verified by what is called a “gap inspection gage”.
Thus, the nut and ferrules are received over the terminal end of the tubing prior to inserting the terminal end of tubing into the recess of the pre-swage tool. The nut is initially finger tightened. Subsequently, a tool such as a wrench is used to tighten the nut the desired amount (1¼ turns), but more assuredly until the torque dramatically increases when the nut engages the body (e.g., collar surface). The nut is subsequently loosed by counter-rotation of the nut, and the tube can thereby be removed from the pre-swage tool. As a result, the tubing, nut, and ferrules are now ready for proper installation in the fitting.
This written description uses examples to describe the disclosure, including the best mode, and also to enable any person skilled in the art to make and use the disclosure. Other examples that occur to those skilled in the art are intended to be within the scope of the invention if they have structural elements that do not differ from the same concept, or if they include equivalent structural elements with insubstantial differences.
Claims
1. A controlled pullup gageable preswage tool for use with an associated fitting assembly that includes an associated nut, at least one associated ferrule, and an associated tube, the preswage tool comprising:
- a first body including a first, proximal end and a distal, second end spaced therefrom along a longitudinal body axis, the first body member including a first, engaging surface, and further including first and second tool flats disposed on an external surface thereof;
- a second body member having a proximal, first end and a distal, second end spaced therefrom, the second body member mounted to the first body member for selective rotation relative thereto, the second body member including a second, engaging surface that is disposed in facing relation with the first, engaging surface of the first body member and able to move relative thereto when an axial load is less than a predetermined level, and the first, engaging surface does not move relative to the second, engaging surface of the second body member when the axial load applied to the first and second bodies exceeds the predetermined level, and
- an externally threaded region extending from the first, proximal end of one of the first and second bodies, the externally threaded region dimensioned for threaded engagement with the associated nut surrounding a recess in the first, proximal end of the one of the first and second bodies, and dimensioned to receive an end portion of the associated tube.
2. The preswage tool of claim 1 wherein the axial load applied to the first and second body members advances the body members toward one another.
3. The preswage tool of claim 1 wherein the externally threaded region extends from the proximal end of the first body, and the second body is an annular collar received around the first body.
4. The preswage tool of claim 1 wherein the externally threaded region extends from the proximal end of the second body, and the second body is received in a cavity formed in first body.
5. The preswage tool of claim 4 wherein the first body includes a shoulder and the second body includes a shoulder disposed in facing relation to one another, and defining an extent by which the externally threaded region of the second body extends outwardly from the first body.
6. The preswage tool of claim 4 further comprising at least one retaining member joining the first and second bodies together.
7. The preswage tool of claim 4 further comprising at least first and second retaining pins radially interconnecting the first and second bodies together.
8. The preswage tool of claim 7 wherein the retaining pins are equi-spaced around the first and second bodies.
9. A method of preswaging ferrules received in a nut on a tube, the method comprising:
- providing a preswage tool that includes first and second bodies that selectively rotate relative to one another,
- providing an externally threaded region on one of the first and second bodies;
- placing the ferrules and nut on the tube; and
- subsequently threadedly advancing the nut on the externally threaded region until the first and second bodies of the preswage tool no longer rotate relative to one another.
10. The method of claim 9 further comprising advancing the nut on the externally threaded region until the torque required for make-up rapidly increases.
11. The method of claim 9 further comprising providing the externally threaded region on the first body.
12. The method of claim 11 wherein the second body is a collar rotatably received over the first body at an end thereof adjacent the nut, tube and ferrules.
13. The method of claim 12 further comprising providing a recess in the first body that receives a terminal end of the tube.
14. The method of claim 9 further comprising providing the externally threaded region on the second body where the second body is partially received in a cavity of the first body.
15. The method of claim 9 further comprising retaining the first and second bodies together with frangible pins.
16. The method of claim 15 further comprising situating a seal between the first and second bodies.
17. The method of claim 9 further comprising loosening the nut from the externally threaded region after the first and second bodies of the preswage tool no longer rotate relative to one another.
18. The method of claim 17 further comprising removing the tube from a recess of the preswage tool.
Type: Application
Filed: Oct 19, 2017
Publication Date: Apr 19, 2018
Inventor: Lonnie E. Johnston (Port Charlotte, FL)
Application Number: 15/787,878