U.S. patent application number 15/932128 was filed with the patent office on 2019-08-08 for mandrel with elastic sleeve utilizing hydraulic pressure for hydroforming hollow metal cylinders.
The applicant listed for this patent is Russell D. Wasson. Invention is credited to Russell D. Wasson.
Application Number | 20190240714 15/932128 |
Document ID | / |
Family ID | 67475960 |
Filed Date | 2019-08-08 |
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United States Patent
Application |
20190240714 |
Kind Code |
A1 |
Wasson; Russell D. |
August 8, 2019 |
MANDREL WITH ELASTIC SLEEVE UTILIZING HYDRAULIC PRESSURE FOR
HYDROFORMING HOLLOW METAL CYLINDERS
Abstract
A mandrel with an elastic sleeve utilizing hydraulic pressure
for hydroforming hollow metal cylinders is disclosed. This
invention simplifies the manufacturing process of the hydroforming
device and reduces the associated cost, through the use of fluid
pressures upon the elastic sleeve that biases forcefully against
the interior of the metal cylinder being shaped. In the case where
containment of the hydorforming fluid is desired, so as to prevent
any contamination of the interior of the cylinder being shaped,
this technology can provide that containment more reliably. The
elastic sleeve material used is reasonably flexible, and more
durable than other materials used in related devices.
Inventors: |
Wasson; Russell D.;
(Bourbon, MO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wasson; Russell D. |
Bourbon |
MO |
US |
|
|
Family ID: |
67475960 |
Appl. No.: |
15/932128 |
Filed: |
February 7, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B21D 35/005 20130101;
B21D 39/203 20130101; B21D 39/06 20130101; B21D 26/041
20130101 |
International
Class: |
B21D 26/041 20060101
B21D026/041 |
Claims
1. An apparatus for radially expanding a cylinder by hydroforming
the same utilizing hydraulic pressure, comprising: a metal cylinder
to be expanded; a mandrel provided for insertion into said metal
cylinder in preparation for performance of the hydroforming
function; an elastic sleeve provided upon the mandrel at least
along a portion of its length, and said elastic sleeve arranged in
contiguity with the interior of the cylinder to be hydroformed;
said mandrel having an internal approximate axial pathway through
which hydraulic fluids may insert during hydroforming, said mandrel
having at least one approximate radial pathway extending from its
axial pathway to the surface of the mandrel, and said pathways
providing the means for introducing a pressurized fluid to the area
between the mandrel and its elastic sleeve to expand the elastic
sleeve against the interior of the cylinder being hydroformed
interiorly thereof; seals provided between the elastic sleeve and
the surface of the mandrel to seal in pressurized fluid during
hydroforming; said mandrel at one end having an adapter to which a
high pressure fluid source may connect therewith for introducing
pressurized fluids into the mandrel in preparation for the
performance of hydroforming process upon the associated metal
cylinder.
2. The apparatus of claim 1 and including a series of O-rings
provided upon said mandrel and the interior of said elastic sleeve
to contain the pressurized fluids therein during performance of a
hydroforming function.
3. The apparatus of claim 1, wherein said elastic sleeve slides
onto said mandrel and contacts the O-rings operatively associated
with said mandrel to form a hydraulic fluid pressure expansion zone
between said elastic sleeve, and the exterior of said mandrel, to
obtain expansion of the elastic cylinder when hydroforming a metal
cylinder into an expanded shape.
4. The apparatus of claim 3, wherein said elastic sleeve extends
over the substantial length of the said mandrel when assembled for
a hydroforming operation.
5. The apparatus of claim 4, and including a bushing provided at
each end of the elastic sleeve, and retaining washers and threaded
nuts applied to each end of the mandrel to hold the said bushings
in place against the ends of the elastic sleeve to assure retention
of the pressurized hydraulic fluid during performance of a
hydroforming operation.
6. The apparatus of claim 5, and including a back up ring provided
between the end of the mandrel and within the adapter to maintain a
seal of the pressurized fluid as it enters into the mandrel during
performance of a hydroforming function.
7. The apparatus of claim 6, and including a further O-ring
provided to form the seal between the adapter and the proximate end
of the mandrel to assure fluid sealing at that position.
8. The apparatus of claim 1, wherein said elastic sleeve is formed
of a polymer.
9. The apparatus of claim 8, said polymer is a polyurethane.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a non-provisional application upon the
provisional patent application having Ser. No. 62/456,865 filed on
Feb. 9, 2017.
FIELD OF INVENTION
[0002] This invention relates to the use of fluid pressures to
radially hydroform a metal cylinder into the precise shape and
dimensions required for the finished product, including an elastic
sleeve that expands against the interior of the cylinder to attain
its precise required dimension.
BACKGROUND OF THE INVENTION
[0003] When using a fluid to radially hydroform a metal cylinder,
it is often desirable to keep the fluid self-contained for various
reasons including but not limited to contamination of the material
to be formed, loss of a valuable fluid, or contamination of
surrounding environment with said fluid.
[0004] Other methods for hydroforming metal cylinders can be more
expensive and complex to manufacture. Other methods for
hydroforming may also not contain the fluid used for the
hydoforming process. Many forms of apparatus used to hydroform
metal cylinders rely on a soft material such as an O-ring to be in
intimate contact with the mandrel OD and the cylinder ID before,
during and after hydroforming. This can lead to considerable
resistance and require high amounts of force to insert and remove
the apparatus. The O-rings are vulnerable to cuts and tears during
the insertion process which leads to premature O-ring failure and
insufficient retention of the pressure required to hydroform the
metal cylinder.
[0005] The inventor herein has obtained various prior United States
patents relating to the technology of a System and Method for
Radially Expanding Hollow Cylindrical Objects, such as can be seen
in his U.S. Pat. No. 9,468,966. He has also obtained U.S. Pat. No.
9,027,601, upon Hydraulically Installed Tube Plug, Tube Plug
Installation Tooling, and Installation System and Method.
SUMMARY OF THE INVENTION
[0006] This invention contemplates the hydroforming of hollow metal
cylinders, and attains such through the expansion of an elastic
sleeve maintained within the cylinder and subjected to substantial
fluid compression for attaining the reshaping of the subject's
cylinder from the use of hydraulically stimulating pressures
through the application of the subject matter and mechanics of this
invention.
[0007] The present embodiment accomplishes the above objectives.
The apparatus utilizing an elastic sleeve does not rely on trapped
fluid between the mandrel OD and the cylinder ID to hydroform the
cylinder. There are no O-rings or soft seal materials required to
be in intimate contact with the cylinder ID prior to introducing
the fluid for the hydroforming process or after its completion.
This eliminates the requirement for soft seal material in the
annular space between the apparatus and the metal cylinder that is
to be hydroformed along with the issue of cuts and tears associated
with such soft materials. This also eliminates the high forces that
may be required to insert and remove the hydroforming
apparatus.
[0008] It includes a hard metal mandrel shaft inside an elastic
sleeve. The mandrel shaft shall provide a means of positioning and
retaining the elastic sleeve in a precise location axially along
the mandrel in itself thus defining an expansion zone. Preferably
this will be accomplished with a combination of bushings and
locking nuts and manufactured from an inelastic material such as
metal. The mandrel shaft shall have an axial path in its center
intersecting with a radial path that exits within the boundaries of
the elastic sleeve. This path will be used as a means of
introducing pressurized fluid into the annular space between the
mandrel OD and the elastic sleeve ID. The mandrel shaft will have
an annular grooves located between the source of the pressurized
fluid exiting the mandrel shaft and prior to each end of the
elastic sleeve. A soft elastic material such as an O-ring shall
reside in the annular groove to provide a seal between the mandrel
shaft OD and the elastic sleeve ID.
[0009] In the case where containment of the hydroforming fluid is
desired, this technology can provide that containment more
reliably. The elastic sleeve material used is more durable than
other materials used in similar devices, thus allowing more
expansions, and reducing the amount of unproductive time spent
replacing tooling parts. This embodiment simplifies the
manufacturing process of the hydoforming device and reduces the
associated cost. Other features and advantages of the embodiment
will become more apparent in the following drawings and detailed
description.
[0010] The object of this invention is to eliminate the need for
soft material seals between the expansion apparatus OD and the ID
of the metal cylinder by radially hydroformed along with the
concern for cuts and tears associated with the use of these seals.
To reduce the operator fatigue associated with inserting and
removing an apparatus that utilizes the soft seals previously
discussed. To provide an apparatus that contains the pressurized
fluid during operation and returns it automatically to its source
when the pressure is reduced. To reduce the cost of manufacturing
by simplifying the design of the apparatus and increase the
reliability.
[0011] Other objects and purposes for the subject matter of this
invention may occur to those skilled in the art upon review of the
disclosure as provided herein. Such variations, if within the
spirit of this invention, are intended to be encompassed within the
scope of any claims to patent protection issuing from this
application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In referring to the drawings:
[0013] FIG. 1 is an exploded prospective view of a disassembled
mandrel assembly;
[0014] FIG. 2 is a longitudinal cross section of a mandrel assembly
positioned in a tube located in a tube sheet ready to begin
expanding;
[0015] FIG. 3 is an enlarged longitudinal cross section of the
overlapping mating surfaces of an elastic sleeve and a sleeve
retaining bushing;
[0016] FIG. 4 is a longitudinal cross section of the overlapping
mating surfaces of an elastic sleeve and a sleeve retaining bushing
described in the second embodiment; and
[0017] FIG. 5. is a longitudinal cross section of the overlapping
mating surfaces of an elastic sleeve and a sleeve retaining bushing
described in the third embodiment.
VARIOUS COMPONENTS OF THE INVENTION
[0018] M. Mandrel Assembly [0019] 1. Mandrel Shaft [0020] 2.
Reduced OD of Mandrel Shaft between Annular Grooves [0021] 3. 3a
& 3b--Threaded Sections [0022] 4. 4a & 4b--Annular Grooves
[0023] 5. High Pressure Connector [0024] 6. Recessed Section [0025]
7. Polyurethane Back-up ring [0026] 8. O-ring [0027] 9. 9a &
9b--O-rings [0028] 10. Elastic Sleeve [0029] 11. Sleeve Retainer
Bushing 11a & 11b [0030] 12. Spacer washers 12a & 12b
[0031] 13. Nuts 13a & 13b [0032] 14. Axial Passageway [0033]
15. Radial Passageway [0034] 17. Mandrel Adapter--Threaded [0035]
20. Mandrel Assembly Sleeve retaining bushing [0036] 21. Bushing
Threads [0037] 22. Locking nut [0038] 23. Sleeve retaining bushing
[0039] 24. Sleeve internal threads
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Description of the First Embodiment
[0040] Referring to FIG. 1 and FIG. 2, a mandrel assembly is made
up of the following components. The components are made of
appropriate high strength materials such as, but not limited to,
steel, stainless steel, titanium, high strength metal alloys and
plastic ceramics. An elastic sleeve, usually of a polymer, and made
of polyurethane or similar materials with good machining and high
elasticity properties. The choice of materials can vary based on
the application and environmental requirements that the assembly
may be used in it.
[0041] A mandrel shaft 1 is made up of an appropriate high strength
material and is generally formed of a uniform diameter along its
length where it joins with reduced diameter threaded sections 3a
& 3b, and a further reduced diameter high pressure connection 5
outboard of threaded section 3b. This allows components mounted
thereon to be slid off and replaced when required. Annular grooves
4a & 4b are formed in the major diameter section of the mandrel
shaft 1. The mandrel shaft OD 2 between the annular grooves 4a
& 4b is of a reduced OD slightly less than the major OD
outboard of the grooves 4a & 4b. O-rings 9a & 9b which are
made of a suitably soft material as known in the art encircle the
mandrel shaft 1 and sit in the annular grooves 4a & 4b. The
high pressure connection 5 is capable of joining the shaft to a
variable pressure fluid supply up to 60,000 psi and has an annular
recess 6 formed in it. A polyurethane backup ring 7 and O-ring 8,
which is made of a suitably soft material, sits in the annular
recess 6. The inner diameters of backup 7 and O-ring 8 must be
slightly smaller than the annular recess 6 diameter. The outer
diameter of backup 7 must be slightly smaller than the major
diameter of the high pressure connector 5. The outer diameter of
O-ring 8 must be slightly larger than the major diameter of the
high pressure connector 5. An elastic sleeve 10 made of an
appropriate material, as aforesaid, with good machining and elastic
properties with an ID slightly larger than the mandrel shaft 1
major diameter allows it to slide in an axial direction on the
mandrel shaft 1. The elastic sleeve 10 major OD is equal to the
sleeve retainer bushings 11a & 11b OD. Sleeve retainer bushings
11a & 11b are made of an appropriate high strength material
with an ID slightly larger than the OD of the mandrel shaft 1, has
a major diameter to allow it to slide freely in an axial direction
on the mandrel shaft 1. The mating surfaces 16a & 16b of the
elastic sleeve 10 and sleeve retainer bushing 11a & 11b that
overrides and join with the elastic expander 10 surfaces are an
interference fit. The elastic sleeve 10 and sleeve retainer bushing
11a & 11b mating surfaces 16a & 16b can be an overlapping
bevel surface, an overlapping step surface, or overlapping
interlocking mating surfaces 16a as depicted in FIG. 3.
[0042] Outboard and adjacent to the sleeve retainer bushings 11a
& 11b are retaining washers 12a & 12b are made of an
appropriate high strength material with an ID slightly larger than
the OD of the threaded sections 3a & 3b of the mandrel shaft 1,
and an OD equal to the OD of the sleeve retainer bushings 11a&
11b. Outboard and adjacent to retaining washers 12a & 12b are
nuts 13a & 13b that are secured in threaded engagement with
threaded sections 3a & 3b of the mandrel shaft 1 and limits the
axial movement of the components on the mandrel shaft 1 locking
them in place. The mandrel shaft 1 has an axial oriented central
bore 14 that intersects with a radially oriented bore 15 to provide
a path for the pressurized fluid to reach the annular void between
the mandrel shaft 1 and the elastic sleeve 10. Various
configurations of high pressure adapters can be threaded onto the
threaded end 3b of the mandrel to connect the mandrel shaft 1 to a
high pressure fluid source.
[0043] The adapter 17, shown in FIG. 1 and FIG. 2, is shown as an
example only and is not the sole means of connecting the mandrel
shaft 1 to a high pressure fluid source. A high pressure flexible
hose (not shown) may be attached directly to the mandrel assembly
through an appropriately threaded mandrel adapter and used to
supply pressurized fluid. This configuration allows for positioning
the mandrel down a tube to a predetermined position from the tube
end to hydroform the tube. The mandrel shaft 1 can be modified by
continuing the axial passageway 14 through the mandrel shaft 1
instead of stopping it mid-shaft, and a high pressure connection 5
added to the threaded section 3a, may work appropriately at that
end of the mandrel. This allows multiple mandrel assemblies of
varying lengths to be interconnected end to end with
interconnections of varying lengths. When activated, multiple
locations can be hydroformed at similar or varying expansion
lengths at the same time. The mandrel shaft 1 can include a safety
vent passageway that allows the mandrel to be safely used to
hydroform a hollow cylinder with a blind hole. The mandrel can be
attached to a hand-held mandrel holder or a robotically controlled
mandrel holder by changing the configuration of the mandrel adapter
connections. An adjustable stop collar can be attached to the
mandrel adapter by threads to facilitate fine adjustments in the
mandrel insertion placement.
[0044] A technician would assemble the system as indicated above.
The person would then insert the mandrel assembly into the material
to be hydroformed. The person would actuate the power supply using
either a remote operation switch on the mandrel holder handle or
using a manual operation switch located on the power supply.
Pressurized fluid would then be pumped from the power supply via a
suitable umbilical capable of delivering the maximum rated output
from the power supply's pump. The pressurized fluid will enter the
mandrel via passageways 14 & 15 and enter the annular void
between mandrel shaft 1 and the elastic expander 10. The
pressurized fluid fills the void and exerts pressure radially on
the elastic expander 10. The elastic expander 10 deforms radially
exerting pressure on the metal cylinder, expanding it radially. The
person would hold the switch until the indicators would indicate
the hydroforming process is complete. When the hydroforming process
is complete, the person would release the switch and then remove
the mandrel assembly from the material.
Description of the Second Embodiment
[0045] Refer to FIG. 4. The sleeve retaining bushing 20 may have
internal threads 21 to engage external threads on the locking nut
22, thereby combining the sleeve retaining bushing, retaining
washer, and locking nut functions into one piece.
Description of the Third Embodiment
[0046] Refer to FIG. 5. The sleeve retaining bushing 23 used on the
primary end of the mandrel (end nearest to the high pressure fluid
source) may have internal threads 24 to match the threads on the
mandrel shaft 1. It may have a major OD machined equal to or larger
than the cylinder being expanded to facilitate precise positioning
of the mandrel assembly, by indexing it off the end of the cylinder
to be expanded. Thereby combining the sleeve retaining bushing,
retaining washer, locking nut, and positioning collar functions
into one piece.
[0047] Variations or modifications to the subject matter of this
invention may occur to those skilled in the art upon review of the
summary of the invention as provided herein, and upon undertaking a
study of the description of its preferred embodiment, in view of
the drawings. The subject matter of this invention as explained, is
set forth for illustrative purposes only.
* * * * *