Radiator clamping jig

A clamping jig releasably holds a workpiece of elongate cross section such as a radiator core. The jig includes an upright frame and a parallelogram-shaped horizontal articulated linkage having a pair of parallel side rails and a pair of end members pivotally connected to the ends of the side rails for movement about vertical axes. The side rails are spaced apart a distance greater than the width of a radiator core, and are moved by a pneumatic cylinder or other actuator so that the links pivot about their axes, and the side rails move closer together to clamp the radiator core between them. The clamping mechanism is operated by a foot pedal, for hands free operation. The vertical height of the parallelogram linkage may be readily adjusted, and hold-down elements are provided to exert a downward pressure on the radiator when it is held clamped between the side rails.

The present invention relates to a clamping jig assembly for holding a 
workpiece. In particular, the invention is directed to a radiator clamping 
jig for securing a radiator core while it is crimped onto, or decrimped 
from, a header tank. 
Vehicle radiators normally comprise a heat exchanger core, a header and a 
tank on top thereof. The heat exchanger core typically comprises a number 
of vertical tubes and a plurality of closely spaced horizontal fins 
connected to the tubes for dissipating heat from the fluid passing through 
the tubes. The tubes and fins are normally made of metal, such as copper 
or steel. The header receives the top of the core tubes and forms the 
bottom of the tank. The tank portion is joined to the header to form a 
fluid reservoir. 
Conventionally, the tank is also made of metal, such as brass, and is 
formed integrally with the header, or braised, soldered or otherwise 
welded thereto. However, such radiator construction is labour intensive 
and time consuming, and consequently expensive. Furthermore, welded 
all-metal radiators are difficult and costly to repair. In recent times, 
vehicle manufacturers have commenced using tanks of heat resistant 
plastics materials in order to minimise manufacturing costs, and radiator 
repairers have similarly begun to replace brass tanks with plastic tanks. 
The tanks are mechanically connected to the cores using a crimping 
procedure to form a sealed connection between the tank and the header. 
More specifically, the plastic tank is positioned against a gasket or 
O-ring seal received in a header recess, and a tank flange is compressed 
against the gasket and secured in position with a series of tabs formed 
integrally with the header which are crimped to retain the tank compressed 
against the gasket. Alternatively, separate crimping strips can be placed 
around the header and tank flange, and crimped to maintain a sealed joint 
between the tank and header. 
This crimping procedure is normally carried out using a radiator clamping 
jig to secure the core and header in a suitable position, typically, waist 
height, while the tabs or lugs are crimped one by one around the periphery 
of the header. The jigs are also used during decrimping procedures when 
the crimped tabs are opened out to remove the tank from the header. 
There are various known clamping jigs, most of which are of the form 
comprising two parallel elongated side rails or walls which are brought 
together to clamp the radiator core between them. In one simple 
arrangement, the two side rails are slidably mounted on transverse rails 
on a vertical frame. One operator is required to support the core between 
the side rails while another operator brings the side rails up against the 
sides of the core and secures them in that position. In a modification of 
this arrangement, the side rails are mounted on a worm drive to enable 
them to be closed against the core by turning a winder wheel. Although 
this modification enables the radiator clamping procedure to be conducted 
by one operator, it requires the operator to support and steady the heat 
exchanger with one hand while turning the worm drive wheel with the other. 
As many cores are heavy and awkward to handle, the procedure is still 
difficult and time consuming to carry out by a single operator. 
In another known radiator clamping jig, one side rail is mounted on 
pneumatic rams which are operated by a control lever at one side of the 
vertical frame. This arrangement provides speedy clamping. However, it 
still requires the operator to hold the heat exchanger with one hand while 
operating the control lever with the other. Furthermore, the side rails of 
this jig are both located on one side of the vertical frame, and the 
radiator is therefore held off-centre. While one side of the radiator is 
unencumbered, the other side is often obstructed by the frame thereby 
making it awkward to operate on that side. 
In yet another known radiator clamping jig, illustrated in U.S. Pat. Nos. 
4,411,414 and 4,462,146, two side rails are hingedly connected to the top 
of a frame enabling them to be swung apart to receive a core therebetween 
from underneath. The side walls are then held against opposite sides of 
the core. However, as downward pressure must be applied to the tank during 
the crimping operation, e.g. by vertical rams, an inherent disadvantage of 
the last described jig is that the hingedly connected side rails tend to 
splay under such downward pressure exerted on the tank. As a result, the 
top lip or flange of the header may not be supported correctly by the top 
inside recessed edges of the side rails, thereby hindering proper 
crimping/decrimping or even permitting the core to fall between the rails. 
Moreover, the side rails are at fixed height and may not suit all cores and 
operators. Good ergonomic design requires that the crimping tabs be at 
approximately waist height, and the optimum height of the side rails will 
therefore depend on the particular operator. 
Conventional tools have generally proved unsatisfactory for crimping and 
decrimping procedures. U.S. Pat. No. 4,462,146 describes manual crimping 
and decrimping tools which are specially designed to facilitate the 
crimping/decrimping procedures. However the crimping and decrimping tools 
described in the U.S. Patent are of completely different design. Hence, 
separate tooling is required for their construction, thereby increasing 
manufacturing costs. In addition, the prior art decrimping tool operates 
by pulling the crimped tab backwards and the tab may therefore be folded 
over against itself rather than being opened up. 
Although the manual crimping tool of U.S. Pat. No. 4,462,146 facilitates 
the crimping of the tabs, it is still a slow and tedious process. 
It is a general object of the present invention to overcome or at least 
substantially ameliorate one or more of the above described problems of 
the prior art. 
It is a more specific object of the present invention to provide an 
improved clamping jig which enables the workpiece to be clamped within the 
jig quickly and simply. 
It is another object of the present invention to provide an improved manual 
decrimping tool suitable for use with such clamping jig. 
It is yet another object of the present invention to provide an automated 
crimping mechanism suitable for use with such clamping jig. 
In one broad form, the present invention provides a clamping jig suitable 
for holding a workpiece of elongate cross section such as a radiator core 
or the like, said jig comprising 
an upright frame; and 
clamping means mounted on said frame, said clamping means including a 
parallelogram-shaped horizontal surround having a pair of parallel side 
rails and a pair of end members each pivotally connected to a respective 
end of both side rails; and 
means for pivoting said end members relative to said side rails to vary the 
spacing between said side rails whereby the workpiece may be releasably 
clamped between the side rails. 
Preferably, the frame is a demountable assembly and consists of a pair of 
legs and a crossbeam adapted to be mounted across the top of the legs. The 
clamping means is provided at its ends with sleeve members, typically box 
tubes, which are slidably adjustable in height along the legs. Similarly, 
the crossbeam can be mounted at its ends on sleeve members, such as box 
tubes, which are slidably adjustable along the legs. The sleeve members 
can be fixed into position by means of looking pins inserted in registered 
apertures in the sleeve members and the legs themselves. 
A significant advantage of the demountable frame assembly is that the 
clamping jig can be disassembled quickly and easily for transport, 
servicing or repair. Furthermore, the height of the clamping means and 
crossbeam can be adjusted to suit different radiator cores and operators. 
Preferably, the means for pivoting the end members relative to the side 
rails, i.e. for skewing the parallelogram surround in the horizontal 
plane, comprises a pneumatically operated cylinder. The cylinder may 
suitably be mounted on a sleeve member, the distal end of its piston ram 
being connected to one of the end members. The pneumatic cylinder is 
preferably operated by a foot switch or pedal, thereby providing 
hands-free operation of the clamping means. This leaves both hands free 
for the operator to support and position the workpiece between the side 
walls prior to clamping. 
In the preferred embodiment, the jig is designed for clamping a radiator 
core during the crimping of a plastic tank to the core header, or its 
decrimping. In order to maintain the tank compressed against the header 
during crimping and decrimping operations, one or more upright pneumatic 
cylinders are mounted to the crossbeam and arranged to press downwardly on 
the plastic tank. 
The end members of the clamping parallelogram are preferably mounted so as 
to pivot about respective vertical axes which are located centrally of the 
end members and in approximately the same vertical plane as the overhead 
upright pneumatic cylinder(s). In this manner, the radiator core will be 
automatically clamped centrally with respect to the overhead cylinders 
regardless of the width of the core. 
Advantageously, rail members are provided along the outer sides of the side 
rails for slidably mounting a crimping device, which may be either a 
crimping machine or a manual crimping/decrimping tool. 
According to another aspect of the present invention, there is provided a 
semi-automatic crimping device suitable for crimping tabs on a radiator 
held within the abovedescribed clamping jig, said crimping device 
comprising a housing adapted for mounting to the outer side of said side 
rails and slidable therealong, 
an elongate crimping tool operatively extending forwardly from said housing 
towards the radiator, 
a pneumatically operated mechanism located within said housing and 
connected to said crimping tool, the mechanism being operative to impart a 
combination of forward and downward movements to the forward tip of said 
crimping tool, and 
manually operable switch means on the exterior of said housing for 
actuating said pneumatically operated mechanism. 
In the preferred embodiment, the pneumatically operated mechanism comprises 
a pneumatic diaphragm or cylinder having a ram or piston which is 
connected to the rear end of the crimping tool via a clevis fitting. A cam 
follower mechanism is provided between the crimping tool and the housing 
for constraining the forward tip of the tool to move forwardly and 
downwardly upon extension of the air ram or piston. 
Adjustment means are suitably provided for varying the height and forward 
travel of the tool tip relative to its housing to suit different 
radiators. 
According to yet another aspect of the invention, there is provided a 
manual decrimping tool suitable for use in decrimping crimped tabs on an 
automotive radiator held within the abovedescribed clamping jig, said 
decrimping tool comprising 
a first elongate handle having a transverse channel portion adjacent the 
forward end thereof and adapted to engage the outer side of a side rail of 
said clamping jig; 
a pivot bar having one end pivotally connected to said first handle and its 
other end fixedly connected to a second handle located above said first 
handle; 
a tool bit fastened to the forward end of said second handle and protruding 
longitudinally therefrom, said tool bit having a claw-like tip; and 
a third handle located above said second handle and pivotally connected 
intermediate its ends to said second handle, said third handle having its 
forward end protruding beyond the forward end of said second handle for 
abutment against said side rail, 
whereby squeezing of said second and third handles together will cause said 
third handle to pivot about its forward end and withdraw said second 
handle and the claw tip away from said radiator. 
That is, after first positioning the claw tip at the head of a crimped tab, 
the second and third handles are squeezed together to open out the tab. 
The first (lowermost) handle is relaxed slightly to allow the tool to lift 
while the tab is opened out in an arc. 
The claw tip of the tool bit may be bifurcated to enable two tabs to be 
decrimped simultaneously. A leaf or coil spring may also be provided 
between the second and third handles to bias the handles apart and 
facilitate the controlled squeezing action of the two handles.

The preferred embodiment of the invention is designed for clamping vehicle 
radiator cores. However, the jig is also suitable for clamping other 
workpieces while they are being worked. As shown in FIG. 1, the radiator 
clamping jig 10 of the preferred embodiment comprises a demountable 
assembly consisting of a pair of spaced legs 11, a horizontally-arranged 
clamping means 20 mounted on box tubes 12 which are vertically adjustable 
along the legs 11, a top crossbeam 18 mounted across the top of legs 11, 
and a pair of pneumatic rams 15 mounted to the crossbeam 18. As the 
clamping jig is demountable, it can be disassembled into its component 
parts for transport, servicing or repair. 
Each leg 11 is provided with a base 11A which is fastened to the floor by 
suitable fastening means. Each leg is also provided with a series of 
spaced apertures 11B thereon. Corresponding apertures are provided in the 
box tubes 12 of the clamping means 20 so that the clamping means can be 
locked into position at a desired height by inserting locking pins through 
registered apertures in the box tubes 12 and legs 11. In this manner, the 
height of the clamping means 20 can be adjusted to suit the particular 
core and operator. 
As illustrated more clearly in FIGS. 2 and 3, the clamping means 20 
comprises a parallelogram-shaped linkage arrangement having two opposed 
elongated side rails 21, 22, and two shorter end members 23, 24 each of 
which is pivotally connected to respective ends of the side rails 21, 22. 
The length of end members 23, 24 determines the maximum spacing between 
side rails 21, 22 and is suitably chosen so that all selected radiator 
core/headers can be accommodated between the rails 21, 22 with a 
comfortable working clearance. Due to the pivotal connections between the 
four members of the parallelogram linkage, the end members 23, 24 can be 
pivoted relative to the side rails 2, 22 as illustrated in FIG. 3 so as to 
reduce the spacing between the side rails 21, 22, and thereby clamp the 
radiator/core therebetween. Preferably the four members 21-24 are hinged 
to maintain their vertical orientation during use. 
The end members 23, 24 are pivotally mounted on respective brackets 12A 
formed on the box tubes 12. The vertical pivot pin 16 of each pivotal 
mounting is suitably located midway between the connections of the end 
members 23, 24 to the side walls 21, 22. Furthermore, the pivot pins 16 
are located in the vertical operating plane of the clamping jig assembly, 
i.e. the plane containing air cylinders 15. In this manner, the radiator 
core/header will be automatically centred within the operating plane of 
the clamping jig, and the tank will always be aligned with the rams 15 
mounted on crossbeam 18, regardless of the width of the radiator. 
The parallelogram linkage of the clamping means is initially opened to 
rectangular configuration to maximise the spacing between the side rails 
21, 22. The core is then inserted between the side rails. The clamping of 
the side rails 21, 22 is achieved by skewing or pivoting the parallelogram 
linkage. In the illustrated embodiment, a pneumatically operated cylinder 
13 is mounted on a box tube 12 and has an extendible ram which is 
pivotally connected to a bracket 23A formed on one of the end members 23. 
Extension of the ram of the cylinder 13 in the direction of the arrow A of 
FIG. 2, will bring the side rails 21, 22 together to clamp the core 
therebetween. The cylinder 13 is operated by a foot switch or pedal 14, 
thereby allowing the operator to use both hands to support and position 
the core. The lateral clamping pressure is kept to a minimum to avoid 
damage to the core. Furthermore, the side rails can be closed, opened or 
stopped in any intermediate position by operation of foot pedal 14. 
Although a pneumatic cylinder 13 is preferably used to operate the clamping 
means 20, any other suitable device may be used. For example, a hydraulic 
cylinder or an electro-mechanical device, such as a solenoid, may 
alternatively be used. 
As can be seen more clearly in FIGS. 1 and 4, support strips 21A, 22A are 
fastened to the inside faces of side rails 21, 22 respectively, by 
off-centre fasteners 29. The support strips 21A, 22A are recessed below 
the top of their associated side rails so as to provide a recessed inner 
lip to support the header flange. (In order to change the recess depth, 
the support strips are simply unfastened and inverted. The off-centre 
fastening thereby results in a different recess depth of the inner lip). 
The support strips 21A, 22A can easily be removed to accommodate certain 
cores which use separate crimping strips. 
The radiator header plate may be provided with an integral serrated or 
castellated flange (not shown) forming a series of lugs or tabs extending 
around the top peripheral edge of the header. Alternatively, separate 
crimping strips having a series of tabs can be used. An O-ring seal or 
gasket is placed around a top lip of the header and a plastic tank is 
placed thereon to form a fluid reservoir, the tank having a flange which 
is pressed onto the gasket. When joining a plastic tank to a core, the 
tank must compress the gasket sufficiently against the header to form a 
seal before any crimping is performed. The tabs are only retainers, 
maintaining the pressure seal established by squeezing the tank into the 
gasket. In the preferred embodiment, the plastic tank is pressed against 
the gasket by means of pneumatic rams 15 mounted on crossbeam 18. Box 
tubes 17 are fitted to the ends of the crossbeam to enable the crossbeam 
to be selectively adjusted along legs 11. The crossbeam 18 can be locked 
in a desired position by inserting locking pins through registered 
apertures in the box tubes 17 and legs 11. 
The pneumatic cylinders 15 can be slidably adjusted along the length of 
crossbeam 18, and then locked into position by fastening the cylinder 
mounts. A clevis fitting is provided at the bottom end of the ram of each 
pneumatic cylinder 15, a small bearing plate being fitted to each clevis 
fitting. In this manner, the bearing plate can tilt to accommodate 
inclined tank tops. 
The tabs or lugs formed by the serrated or castellated edge of the header 
flange, or on the crimping strips, are crimped over the tank flange while 
the tank is compressed by rams 15. On retraction of the rams 15, the 
pressure seal between the tank flange, gasket and header will be 
maintained by the crimped lugs, thereby provided a sealed mechanical 
connection of the plastic tank to the core header. 
As the clamping assembly 20 is quite heavy, (approximately 60 kg) it is 
preferable to raise and lower the clamping assembly 20 mechanically in 
order to avoid injury to the operator through manual lifting. The clamping 
assembly 20 can be raised and lowered by means of one or more of the 
pneumatic cylinders 15. The bearing plate is removed from the clevis 
fitting at the bottom end of the ram of the pneumatic cylinder 15, and 
replaced with a beam coupling attachment (not shown) which has a sectional 
shape approximating an inverted "T". The beam coupling attachment is 
lowered between the rails 21, 22 which are then closed about the coupling 
attachment by suitable operation of the pneumatic cylinder 13 by foot 
pedal 14. Preferably, the rails 21, 22 are closed about the coupling 
attachment, but do not clamp it, so that the box tubes 20 slide more 
easily along their respective legs 11. The looking pins in the box tubes 
12 are removed and the clamping assembly 20 is raised and lowered as 
required by operation of the pneumatic cylinder 15. The clamping means can 
be looked into its new position by reinserting the locking pins into the 
registered apertures at the new height. 
To vary the height of the top crossbeam 18, the rails 21, 22 are closed 
together and the rams of the pneumatic cylinders 15 are extended so that 
the bearing plates abut against the tops of rails 21, 22. The locking pins 
in box sections 17 are then removed and the crossbeam can be adjusted to 
the desired height by operation of cylinder(s) 15. It will be apparent to 
those skilled in the art that the spacing between the apertures in legs 11 
will govern the size of the vertical increments in which the top beam 18 
and clamping assembly 20 can be adjusted. 
The crimping of the tabs can be performed manually or by using a crimping 
machine. FIGS. 4 and 5 illustrate an air-operated semi-automatic crimping 
machine 30 which can be slidably mounted on either one of open-ended rails 
26 fixed on the outside of the side rails 21, 22. Only side rail 22 is 
shown in FIG. 4, the construction of the rail 26 on side rail 21 being of 
identical configuration. The rail 26 is spaced from its respective side 
rail 21, 22 by a narrower intermediate rail 26A so that the composite rail 
26, 26A has a T-shaped cross section as shown in FIG. 4. 
The crimping machine 30 is provided on its front face with a hooked flange 
48 which enables it to hang from rail 16. The front face of the crimping 
machine 30 is also provided with a stub axle 47 on which are mounted 
co-axial rollers 45, 46. Roller 46 is designed to roll along the bottom 
face of rail 16 while roller 45 rolls along a bias-mounted support bar 28 
located below each rail 21, 22. As can be seen in FIG. 1, the support bar 
28 is spring-mounted on two short rods 27 connected to the ends of each 
rail 26. Alternatively, the support bar 28 can be mounted on hydraulic or 
pneumatic cylinders. (The function of the support bar 28 will be described 
below). The crimping machine 30 can be inserted onto, and removed from, 
either end of the rail 26 quickly and simply, and is free to slide along 
either rail to operate on both sides of a core clamped within the clamping 
means 20. 
As shown in FIG. 4, the air-operated crimping machine 30 has an inlet 31 
for connection to a source of compressed air. The inlet 31 is connected to 
chamber 36 of a piston assembly within the crimping machine via a push 
button valve 32. On depressing valve button 32 therefore, the valve is 
opened to pressurise the chamber 36 of the piston assembly. One wall of 
the chamber 36 is defined by a flexible diaphragm 37 which expands 
outwardly on pressurization of chamber 36 to extend piston ram 39. 
A crimping mechanism is connected to the distal end of piston ram 39. This 
crimping mechanism comprises a tool bit 35 which is pivotally connected at 
pivot point 40 to a clevis fitting 38 at the end of piston 39. The tool 
bit 35 is also pivotally connected at pivot point 41 to a link member 45 
which, in turn, is pivotally connected at pivot point 42 to a clevis mount 
47 of adjustable height. A transverse slot or recess 44 is provided on the 
top side of the tool bit 35. The free end of the tool bit 35 is provided 
with a crimping tip 35A, typically of hardened steel. A profiled stop 43 
is located above the tool bit as shown in FIG. 4. The recess 44 is 
dimensioned to receive the profiled stop 43. The profiled stop 43 and 
recess 44 act as a cam follower mechanism as explained below. 
Operation of the crimping machine 30 is illustrated schematically in FIGS. 
5A to 5C. Upon pressurization of chamber 36, an axial force will be 
imparted to piston ram 39 and this force will be transmitted to pivot 
point 40. When resolved into its components, the force acting on pivot 
point 40 consists of an upward force and a forward force. As the tool bit 
35 is prevented from moving upward by step 43, it is constrained to move 
forward (i.e. against the tab to be crimped), pivoting on pivot point 42 
as shown in FIG. 5B. Once the tool bit 35 has moved forward to a position 
where the recess 44 is aligned With the profiled stop 43, the tool bit 35 
is able to pivot upwardly about pivot point 41 so that extension 43 will 
be received within recess 44. This causes a downward movement of the tool 
tip 35A as shown in FIG. 5C. Thus, the crimping action of the tool tip 35A 
comprises an initial forward movement followed by a downward movement. The 
cam-like engagement of extension 43 within recess 44 not only provides the 
downward movement at tool tip 35A, but also limits the forward movement of 
the tool bit 35. The height and forward travel limit of the tool tip 35A 
are adjustable by thumbwheel mechanisms, 34, 33, respectively, to suit 
different header flanges and crimping strips. The height and forward 
travel limit are preferably adjusted so that during the initial forward 
thrust of the tool bit 35, the tool tip 35A engages a crimping tab and 
only partially bends it over the edge of the plastic tank flange (which is 
held down on the header gasket under pressure). Subsequently, during the 
downward movement of the tool tip 35A, the tab is crimped onto the tank 
flange to maintain the pressure seal between the tank, gasket and header. 
Preferably, the tool tip 35A is bifurcated to enable two tabs to be crimped 
simultaneously. 
Release of button 32 will close its associated valve to thereby 
depressurize chamber 36. The piston 39 is reversed biased so that when the 
chamber 36 is depressurized, it will retract the tool bit 35 to its 
initial position. The crimping operation is therefore performed simply by 
depressing and releasing the valve button 32. The crimping machine 30 is 
then moved on to the next tab(s) by sliding along rail 26, and the 
procedure is repeated. It will be apparent to those skilled in the art 
that the semi-automatic operation of the crimping machine facilitates the 
crimping operation and enables it to be completed in far less time than 
the manual crimping devices hereto used. 
Automated mechanisms for decrimping have not yet been developed. 
Furthermore, in small operations, the cost of an automated crimping 
machine may not be warranted. For the foregoing reasons, operators still 
use manual decrimping and/or crimping tools. 
FIG. 6A illustrates a crimping tool suitable for use with the clamping jig 
of this invention. The crimping tool comprises a bottom handle 60 having a 
hand grip 65 provided at one end thereof. The bottom handle 60 is 
pivotally connected to a pivot bar 63 in a suitable manner, for example by 
a clevis fitting. A top handle 64 is fastened at right angles to the pivot 
bar 63, and a crimping tool bit 66 is removably mounted on the top of the 
forward end of handle 64 by threaded fasteners 67 e.g. Allen screws. The 
bottom handle 60 is provided with a transverse slot or channel 61 on its 
upper side. 
To commence the manual crimping operation, the crimping tool is mounted to 
a side rail as shown in FIG. 6A. That is, the bottom handle 60 is inserted 
between a rail 16 and its associated spring-loaded support bar 28 such 
that the bottom edge of the rail 16 is received within the channel 61 and 
the handle 60 rests upon the support bar 28. As the support bar 28 is 
spring-loaded or otherwise bias-mounted, it is able to deflect downwardly 
to allow insertion of the bottom handle 60 yet it at least partially 
supports the weight of the crimping tool, thereby facilitating its use. 
The degree of support provided by support bar 28 can be varied to suit the 
operator by adjusting the tension of the springs on rods 27. The height of 
the support bar 28 can also be adjusted by the nuts on threaded rods 27. 
Once the bottom handle is correctly inserted, the forward lip 62 thereof 
will abut against the bottom of intermediate rail 16A. 
With the crimping tool set up as shown in FIG. 6A, the top handle 64 is 
raised to bring the crimping tool tip 66 up into contact with a tab 5 to 
be crimped. During this operation, the top handle 64 and pivot bar 63 
pivot about the connection of the pivot bar 63 to the bottom handle 60. 
While using the handpiece 65 on the shorter bottom handle 60 to control 
the contact height of the tool tip 66 so that it engages near the top edge 
of the tab 5, the top handle 64 is lifted in an arc to push the tab over 
to at least 45 degrees as shown in FIG. 6B. Thereafter, while applying 
sufficient force on the top handle 64 to hold the tool tip 66 against the 
tab 5, a firm downward force is applied to the lower handle 60 to squeeze 
or crimp the tab 5 down flat as shown in FIG. 6C. The crimped tab 5 
maintains the pressure seal between the tank flange 6, gasket or O-ring 
seal 8 and header 7, as shown in FIG. 6D. The crimping tool is then 
reconfigured to its starting configuration shown in FIG. 6A, and moved to 
the next tab to be crimped by sliding between rails 16 and support bar 28. 
This procedure is repeated for all tabs on both sides of the tank, the 
tabs at the ends being crimped with conventional tools. 
A decrimping tool is shown in FIG. 7A. The decrimping tool is similar to 
the crimping tool in that the bottom handle 60 and handpiece 65, pivot bar 
63 and top handle 64 are common to both tools. This results in lower 
tooling and manufacturing costs, and allows the decrimping tool to be 
converted to a crimping tool by relatively simple modification. 
In the decrimping tool, the tool tip 66 of the crimping tool is replaced 
with a decrimping tool tip 73 having a claw end. In addition, a third 
handle is pivotally mounted to the second handle at the decrimping tool 
tip 73 by means of a clevis fitting 70 and pivot pin 72. Operation of the 
decrimping tool will now be described with reference to FIGS. 7A to 7F. 
The bottom handle 60 is inserted between the rail 16 and spring-loaded 
support bar 28 in a similar manner to the crimping tool. The second handle 
64 is then raised to bring the claw end of the decrimping tool tip 73 up 
against the tank 6 as shown in FIG. 7B. Downward pressure is then applied 
to the lower handle 60 to force the claw end of the decrimping tool tip 73 
behind the edge of the tab 5 as shown in FIGS. 7C and 7D. The two top 
handles 64, 71 are then squeezed together like a pair of pliers to pull 
the tab 5 back just clear of the tank as shown in FIGS. 7E and 7F. When 
the two handles 64, 71 are squeezed together, the top handle 71 pivots 
about the abutment of its protruding lower lip 74 against the side rail 
22. As the tool 73 is offset from the centre of rotation of handle 71, the 
tool 73 is withdrawn in an arc to open out the crimped tab 5. During the 
uncrimping of tab 5, moderate pressure is maintained on the bottom handle 
60 to prevent the claw tip from jumping off the tab, yet controlled upward 
movement of the bottom handle 60 is allowed to enable the tab to be 
uncrimped in an arc rather than being pulled straight back against itself. 
By pulling the tab 5 back in an arc, it will be left in an open position 
suitable for recrimping. 
Advantageously, a leaf or coil spring (not shown) is provided between 
handles 64, 71. 
FIGS. 8 and 9 illustrate various types of tool tips which may be used with 
the crimping and uncrimping tools of FIGS. 6 and 7. (Note however, that 
the illustrated tool tips are not exhaustive of all tips which may be 
used). FIGS. 8A and 9A illustrate a simple bull-nosed crimping tip 66 for 
crimping one tab at a time. The crimping tip 68 of FIGS. 8B and 9B has a 
bifurcated tip 68A enabling two tabs to be crimped simultaneously. FIGS. 
8C and 9C illustrate yet another crimping tip 69 having a pointed nose 
69A. 
FIGS. 8D and 9D illustrate the decrimping tip 73 used in the decrimping 
tool of FIG. 8. This tip 73 has a bifurcated claw 73A which enables two 
tabs to be decrimped simultaneously. 
The tool tips are typically made from annealed tool steel, and are suitably 
hardened and tempered. 
The foregoing describes only some embodiments of the invention and 
modifications which are obvious to those skilled in the art may be made 
thereto without departing from the scope of the invention as claimed in 
the following claims.