Riveting tool

A riveting tool includes a tool body having a hydraulic controlled rivet shank clamping assembly and a rivet suction system. A control valve is provided for directing a flow of pressurized air to the rivet clamping assembly and the rivet suction system. The control valve includes a valve rod having a valve rod piston on an upper end and a plurality of radial steps arranged on an outer surface of a lower end. A trigger is mounted slidably in a trigger transverse guide in the tool body and a spring is located within the trigger transverse guide such that pressure applied to the trigger causes the valve rod to move within the control valve from a first to a second position. When the valve rod is in the first position, pressurized air is guided to the rivet suction system. When the valve rod is in the second position, pressurized air is guided to a space below a pneumatic piston. A space above the pneumatic piston is connected to the hydraulic cylinder of the hydraulic controlled rivet shank clamping assembly.

FIELD OF THE INVENTION 
The invention relates to a hydraulic-pneumatic riveting tool arrangement 
with a rivet suction system and rivet shank remainder exhaustion after 
riveting. 
DESCRIPTION OF THE PRIOR ART 
Known hydraulic-pneumatic riveting tools consist of a lower pneumatic part 
which is connected with an upper hydraulic controlled clamping system for 
blind rivet shanks, wherein said clamping system is provided with collets. 
A tool body made of plastic and shaped into a handle is provided with 
metallic press-in liners for guiding a hydraulic and pneumatic piston. In 
the lower pneumatic part of the tool an air valve is disposed and is 
usually controlled by a vertical valve rod. In said lower part there are 
arranged also channels for pressure air passage, serving for air supply 
from a source to a control valve, for connecting said valve with a space 
below the pneumatic piston and for air outlet. Pressure air stream 
starting is carried out by compression of a coiled spring and by rollers 
compressing a bored valve rod, being provided with an inner spring, which 
bears on a supporting ball on its side adjacent to a trigger. Said valve 
rod is provided with steps for sealing O-rings. 
Said known riveting tools are of a relatively complicated structure and are 
relatively heavy which is a highly disadvantageous feature especially when 
said tools are hand operated. Apart from other disadvantages, known 
riveting tools are complicated including the hydraulic piston arrangement 
and the rear screw joint positioned behind the piston which consists of a 
great number of elements (e.g. of doubled spring seatings on the piston 
and a front nozzle consisting of two mutually screwed parts etc.) which 
increase the production costs and the weight of the tool. The known system 
for rivet suctioning comprises a complicated metallic press in liner with 
bored channels. The structure of the valve rod and the triggering system 
is complicated as well. 
SUMMARY OF THE INVENTION 
Said disadvantages are eliminated to a certain extent by the riveting tool 
arrangement according to said invention, consisting of a body being 
connected on one end thereof with a pneumatic lower part and carrying an 
upper part with a hydraulic controlled rivet shank clamping assembly on 
the other end thereof. The clamping assembly is provided with a chuck 
collet and a hydraulic cylinder of said assembly is connected with a space 
above the pneumatic piston upper part, being formed in the tool body. 
A pressure air outlet of a control valve is opened below the lower part of 
the pneumatic piston which is guided in a cylindrical recess in the lower 
part of the tool. The control valve is fastened in the massive partition 
wall of the tool lower part and is connected through a valve rod, guided 
freely in the longitudinal cavity of the body, with a trigger being 
disposed slidably in a linking up transversal guide formed also in the 
tool body. 
The subject-matter of said invention includes a sealed piston body situated 
on the valve rod and an upper stepped end of the piston body which bears 
on a convex leaf spring the upper arm of which is supported on an upper 
wall of the trigger transversal guide and the lower arm of which is 
supported simultaneously against a radial surface of a shoulder of the 
piston body. The trigger sits tightly on said radial surface. An opposite 
lower end of the valve rod, having an outer diameter smaller then the 
diameter of the guiding bore in the massive partition wall in the tool 
lower part, reaches freely by axial shoulder of the same into an inner 
cavity of the valve body. The valve body is seated slidably in a sleeve 
arranged in the massive partition wall of the lower part. A system of 
radial steps is arranged on an outer surface of said lower end of the 
valve rod and number of sealing elements defining functional passage of 
the pressure air in deposited in said sealing elements. The valve rod has 
a through-hole along the whole length thereof which is opened on a lower 
end into the inner cavity of the valve body which is connected with a 
pressure air source and an upper end of the valve rod is opened to a 
system for rivet suction. The structure of the tool is thus simplified and 
the weight of said tool is decreased. 
Three channels for passing the pressurized air are arranged one above the 
other and are opened into the guiding bore of the valve rod in the massive 
partition wall of the tool lower part and three sealing rings of the 
control valve are arranged in radial steps formed along the height of the 
valve rod. In a closed position of said valve, the valve rod bears by its 
lower step on a face seat surface of the valve body below a mouth of the 
supply channel and simultaneously the upper sealing O-ring and the central 
sealing O-ring close annular space between the valve rod and guiding bore 
wall in the massive partition wall above the connecting channel, being 
opened into a space below the pneumatic piston, and near the upper surface 
of the massive partition wall. 
In the opened position of the control valve the third, lower sealing O-ring 
closes said annular space between the supply channel and the connecting 
channel and the central sealing O-ring closes a space between the 
connecting channel and the outlet channel. The opened upper part of the 
guiding bore is connected in said opened position of the control valve 
with a space below the pneumatic piston and the lower part of the guiding 
bore is connected with the inner cavity of the valve body. 
A sealing element may be mounted in a radial groove formed in the inner 
cavity of the valve body. A regulating roller is clamped on the valve body 
located in the inner cavity of the sleeve which is fastened to the lower 
surface of the massive partition wall, and a wall of said regulating 
roller overhanging a part of the sleeve section is provided with an 
L-shaped groove for a free end of a take up pin guiding, said pin is 
fastened in the sleeve. An outer lower surface of the regulating roller in 
its shifted in position fits with the lower edge of the tool lower part. 
Said lower edge may be formed by a lower peripheral surface of a plastic 
ring which is firmly slipped on the tool lower part. Said regulating 
roller is automatically shifted in when said riveting tool is put onto a 
plane surface and, at the same time, is effective for closing the 
regulating air valve of the tool. 
A cylindrical body of the oil gauge is anchored in the massive partition 
wall of the tool lower part and a sealed piston passes through said 
cylindrical body. A compression spring is arranged between a shoulder of 
the sealed piston and a bottom of the cylindrical body and above said 
shoulder there is disposed a safety element, wherein one end of the piston 
fits on a lower surface of the pneumatic piston and the other indicating 
end passes through a hole in the bottom of the cylindrical body. The 
cylindrical body is anchored in the massive partition wall by a double 
step system and a sealing element is disposed on contact walls between the 
two steps. When oil shortage in a hydraulic system of the tool occurs, 
said state is indicated visually by shifting in the oil gauge piston. 
A safety pin is fastened to the body and is disposed in a transversal guide 
of the trigger in a space between a convex leaf spring and the piston 
body. Said safety pin prevents said convex leaf spring from falling out or 
shifting out from an operating position and thus secures the correct 
trigger function. Said convex leaf spring may be formed by a U-shaped 
steel strip, whose arms are provided with opened recesses through which 
passes said piston body. The leaf spring arms bear on a bottom of the 
transversal guide for the trigger.

DESCRIPTION OF SPECIFIC PREFERRED EMBODIMENTS 
A riveting tool consists of two fundamental parts, of a body 45 and of a 
cylindrical pneumatic lower part 44 which are mutually connected by two 
connecting bolts 30. A metallic (aluminium) press-in liner 16 of a 
hydraulic piston 9 is embedded in a plastic body 45 having a handle shape 
and a metallic (aluminium) press-in liner 22 of a pneumatic piston 25 is 
compressed with said metallic press-in liner 16. Said metallic press-in 
liners 16, 22 serve for guiding said steel hydraulic piston 9 and for 
guiding said plastic pneumatic piston 25. The pneumatic piston 25 reaches 
by upper sealed part thereof (a sealing O-ring 23 and a plastic ring 24 of 
the pneumatic piston 25 are mounted in a shoulder of said upper part) into 
the body 45 of the tool and by a lower enlarged sealed part thereof (being 
sealed with an O-ring 26 of the lower part of the pneumatic piston 25) 
into a plastic lower part 44 of the tool. 
Said tool lower part 44 is provided with an inner cylindrical recess 
forming a working surface of the pneumatic piston 25. Said recess is 
terminated on a lower part thereof with a wall of a massive lower 
partition in the whole diameter of the lower part 44. In the massive 
partition wall there are arranged air passing through channels (depicted 
by dashed lines on FIG. 2) which are opened on the outer periphery of the 
lower part 44 into an angled supply valve 33 on the one hand, and to a 
safety valve 34 adjusted to maximum allowed air pressure (7 bar) on the 
other hand. 
An aluminium press-in liner 39 of an air control valve is embedded in the 
massive partition wall of the tool lower part 44, and is provided with a 
valve bush 36 screwed therein. A hole for said press-in liner 39 in the 
massive partition wall continues upwards and forms a guiding hollow of a 
valve rod 46 (FIGS. 5a and 5b) which reaches into a valve body 38 of the 
air regulating valve. 
Two connecting bolts 30 (with washers 31 and nuts 32) connecting the lower 
part 44 with the tool body 45 pass through the massive partition wall. 
After tightening said connecting bolts 30, a definitive position of the 
lower part 44 in relation to the tool body 45 is secured in a fitted 
connection place of both plastic elements, said connection place being 
air-tight in the air working pressure range of the riveting tool. 
A cylindrical body 27 of an oil gauge is anchored in the massive partition 
wall, wherein said oil gauge serves for indication of hydraulic oil volume 
above the pneumatic piston 25. A sealed small piston 28 is guided through 
the cylindrical body 27 and a compression spring 29 is mounted between a 
shoulder thereof and a bottom of the cylindrical body 27, and a safety 
element is mounted above said shoulder. One end of the small piston 28 
bears on a lower surface of the pneumatic piston 25 and second indicating 
end of the same passes through a hole in the bottom of the cylindrical 
body 27. Said cylindrical body 27 is anchored by double-shoulder system in 
the massive partition wall and a sealing O-ring is disposed between said 
two shoulders on contact walls. In normal conditions and during 
satisfactory hydraulic oil quantity, end of the small piston 28 is shifted 
downwards (FIG. 6), whereas during oil insufficiency, said piston end is 
shifted in and is pressed unremittingly by the compression spring 29 into 
contact with the pneumatic piston 25. The piston 25 is protected against 
shifting out, as mentioned above, by a safety spring. A sealing O-ring 
preventing air leakage from a working space under the piston 25 is mounted 
on the small piston 28. 
Blind holes for exchangeable adapters 1 for rivets may be formed in the 
massive partition wall of the tool lower part 44. 
A transversal guide 54 for sliding support of a trigger 49 (terminating in 
a recess 55) is formed in an upper part of the casted tool body 45. A 
piston body 48 of the trigger 49 sealed in said transversal guide 54 by a 
sealing O-ring 53 passes through the transversal guide 54. The piston body 
48 is mounted slidable through the sealing ring 47 on the hollow valve rod 
46 which passes through a vertical cavity of the tool body 45. A convex 
leaf spring 52 bears against an upper end of the piston body 48 with a 
step and an upper arm thereof is supported on an transversal guide upper 
wall 60 of the trigger 49 and a lower arm thereof leans simultaneously 
against a radial surface of a piston body step 58, and said trigger 49 is 
contiguous with said radial surface by its inner surface 59. A safety pin 
51, which is positioned in the trigger transversal guide 54 in a space 
between the convex leaf spring 52 and the piston body 48, is fastened to 
the tool body 45. Said safety pin 51 prevents the convex leaf spring 52 
from falling-out or shifting-out from working position and thus secures 
regular function of the trigger 49. The convex leaf spring 52 is formed by 
U-shaped steel band and arms of the same are provided with opened cut-outs 
through which passes the piston body 48. Arms 56 of the the convex leaf 
spring 52 may be in contact with a bottom of the trigger transversal guide 
54 (see FIG. 1). A take up groove 57 is formed in the trigger body and a 
take up pin 50 passes through said take up groove 57. Both said elements 
take up path stroke of the trigger 49 and consequently the length of the 
hollow valve rod 46 shifting movement. A lower end of the valve rod 46, 
having outer diameter smaller than that of a guiding cavity formed in the 
massive partition wall of the tool lower part 44, reaches freely by its 
axial shoulder into an inner cavity of the valve body 38 which is slidably 
mounted with a sealing element 37 in a sleeve 36 (said sleeve 36 is 
screwed in the corresponding metallic press-in liner in the massive 
partition wall of the lower part 44 and is provided with a stepped hole 
serving as a guiding path for the valve body 38) in the massive partition 
wall of the lower part 44 (see FIGS. 5a and 5b). A group of radial steps 
and sealing members disposed therein is arranged on an outer surface of 
said lower end of the valve rod 46, said group defines functional passage 
of pressure air. The valve rod 46 is provided in the whole length thereof 
with a through-bore which is opened at its lower end into the inner cavity 
of the valve body 38 being connected with a pressure air source, and which 
is opened at its upper end to the rivet suction system. Three channels 65, 
66, 67, disposed one above the other and arranged for pressure air supply, 
are opened into a guiding cavity of the valve rod 46 in the massive 
partition wall of the tool lower part 44. Three sealing O-rings 40a, 40b, 
41 of the control valve are situated on the valve rod 46 in the radial 
shoulders having different diameters. A slot for pressure air supply 
depending on valve rod position in relation to the valve body 38 is formed 
among said sealing rings 40a, 40b 41 on the circumference of the valve rod 
46. In a closed position of the control valve the valve rod 46 bears on by 
lower shoulder thereof onto a face seat surface of the valve body 38 below 
a throat of a supply channel 65 (leading from the angled supply valve 33) 
. The upper sealing O-ring 41 and the central sealing O-ring 40b close 
simultaneously an annular space between the hollow valve rod 46 and the 
guiding hollow wall in the massive partition wall both above the 
connecting channel 66, leading into a space below the pneumatic piston 25, 
and close to an upper surface of the massive partition wall. 
In an opened position of the control valve the third lower sealing O-ring 
40a closes said annular space between the supply channel 65 and the 
connecting channel 66 and the central sealing O-ring 40b closes a space 
between the connecting channel 66 and the outlet channel 67. Opened upper 
part of the guiding bore is connected, in said opened position of the 
control valve, with a space below said pneumatic piston 25 and the lower 
part of the guiding hollow (bore) is connected with the inner cavity of 
the valve body 38. Said inner cavity is formed with a blind hole in the 
axis of the valve body 38 on an end thereof being adjacent to the valve 
rod 46. The valve body 38 is provided with a sealing element (O-ring) in a 
radial groove formed in its inner hollow. 
A regulating roller 35 is fastened by means of a resilient pin 61 on the 
valve body 38 mounted in the inner cavity of the sleeve 36 which is 
fastened to the lower surface of the massive partition wall. In the wall 
of the regulating roller 35, overhanging the part of the sleeve 36, is 
formed an L shaped groove which is intended for guiding the free end of 
the elastic take up pin 62, wherein said take up pin 62 is fastened in the 
sleeve 36. The take up pin 62 secures the exact shift out position and 
angular displacement of the regulating roller 35. An outer lower surface 
of the regulating roller 35 fits with a lower edge of the lower tool part 
44 in a shifted in position thereof. Said lower edge is formed by a lower 
peripheral surface of the plastic ring which is slipped rigidly on the 
lower part 44 of the riveting tool. After putting said tool on a plane 
surface, the regulating roller 35 is shifted in and is guided in a 
vertical part of the L-shaped groove. 
Each through-bore in the pneumatic piston body is sealed by O-ring against 
pressure air leakage (e.g. said valve rod 46 is sealed by pertinent 
sealing O-ring 43 in the mentioned passage, wherein a plastic ring 42 is 
slipped below said sealing ring 43). 
The pneumatic piston 25 reaches by a narrower part thereof into a 
cylindrical guide in the metallic press-in liner 22. In order to increase 
the pneumatic piston working pressure, said cylindrical guide is provided 
on its narrowing cross-section with a number of steps and is opened into a 
working space of the hydraulic piston 9 in the upper part of the tool. 
A tube 8 is pressed in an axial through-hole of the hydraulic piston 9 
disposed in the axis thereof, said tube 8 serves as a guiding element for 
a spring 17 seating on a shoulder in a rear screw joint 21 which is 
screwed in the press-in liner 16 of the hydraulic piston 9. From the 
opposite side to the rear screw joint is fastened a catching box 20 for 
teared off rivet shanks after riveting operation. Said catching box 20 is 
provided with small holes for air passing and is secured by elastic pawl 
to the rear screw joint 21 in such a way that catching of rivet shanks 
would be safe (the pawl opens a central hole for rivet shanks passing by 
means of the spring and simultaneously secures the catching box 20 against 
falling out). The tube 8 and the catching box 20 are sealed by sealing 
O-rings 18, 19 to the rear screw joint 21. 
The hydraulic piston 9 is provided with a number of sealing elements (the 
sealing O-rings 7, 10, 14 and the plastic rings 11, 15) which prevent from 
oil leakage on all working diameters of the piston cylindrical surface. A 
filling hole for oil refilling is formed in the press-in liner 16 of the 
hydraulic piston 9. Said hole is secured, in the operating mode of the 
tool, by a strength screw 12 with its sealing element 13 (sealing O-ring). 
During oil refilling said screw 12 is removed and a filling jig (see FIG. 
8) is screwed in the hole, wherein said filling jig is formed by a syringe 
having an oil tip 63. Said oil tip 63 is screwed on a respective screw 64 
which passes through a syringe body and is sealed therein. 
A compression spring 6 of a chuck collet 3 seats on the tube 8 on an 
opposite end of the hydraulic piston 9 with respect to the catching box 20 
and an expanding mandrel 5 is mounted in said compression spring 6 from 
its opposite side. Face surface of the expanding mandrel 5 is shaped in 
accordance with bevel of the adjacent chuck collets 3 which are inserted 
freely into a chuck collet sleeve 4 screwed onto the hydraulic piston 9. 
Said rivet shank clamping unit is disposed in a front die 2 which is 
screwed into the press-in liner 16 of the hydraulic piston 9. The 
exchangeable adapter 1, being adapted to different shank diameters, serves 
for rivet shanks guiding and is screwed in the face wall of the front die 
2. 
Auxiliary suction of pressure air is directed into a space ahead of the 
hydraulic piston 9 through the inner hole of the valve rod 46 and the 
piston body 48. Said auxiliary suction serves for holding-down the rivet 
to the tool and thus enables riveting in any working position. Pressure 
air passes through the angled supply valve 33 into the supply channel 65 
in the massive partition wall of the tool lower part 44 (see FIG. 5a). The 
lower sealing O-ring 40 of the control valve closes air passage below the 
pneumatic piston 25 and air streams into the space below the valve rod 46 
(into the blind hole in the valve body 38) and through valve rod cavity 
upwards below the hydraulic piston 9 (see FIG. 9) the guiding surface of 
which is partially slightly stepped. That arrangement forms a gap for air 
passage between the hydraulic piston 9 and the press-in liner 16 of the 
hydraulic piston 9, wherein said press in liner 16 is screwed on the tool 
front die 2. Air streams into a space 70, disposed between said slight 
stepped part and a stepped part, comprising a groove for the sealing 
O-ring 7 which prevents air from entering into other part of a riveting 
tool. The hydraulic piston 9 and the tube 8 of the hydraulic piston 9 are 
moved simultaneously in a direction perpendicular to the axis of the 
hydraulic piston 9 in such a way that air may stream through drilled holes 
into a cavity of the tube 8. An inner bored small piston 69 is pressed in 
the front part of the tube 8 and is multiply stepped and provided with a 
necking-down for a sealing O-ring 68 thereof. A bore of the small piston 
69 terminates by an extended conical bevel into this piston face, wherein 
said conical bevel serves for improved air suction into the small piston 
bore. Air streams subsequently through the tube 8 and the rear screw joint 
21 into the catching box 20 for collecting teared off rivet shanks and 
exits through bores drilled on a periphery thereof. A rivet inserted in 
the adapter 1 is thus held by the suction of air stream to the tool and 
the tool may operate in arbitrary position without any risk that the rivet 
falls out. 
After compression the trigger 49 acts to the leaf spring 52 which by action 
of said compression power straightens and causes movement of the piston 
body 48 with the valve rod 46 downwards into space of the control valve 
(see FIG. 5b). In this state, passage of air takes place through the 
supply channel 65 (the valve body 38 seats on the step of the valve rod 46 
and prevents air from passing under the valve rod 46) and through a 
annular slot between the valve rod 46 and a guiding cavity wall in the 
massive partition wall of the tool lower part 44 into the connecting 
channel 66 which is opened into a space below the pneumatic piston 25. 
Other sealing O-rings 40, 41 on the valve rod 46, which are situated above 
the connecting channel 66, prevent air from passing into the outlet 
channel 67 that serves for safe transferring of the pressure air from the 
tool (in case of an air pressure that exceeds the maximum allowable 
pressure of the sealing O-rings 40, 41 on the valve rod 46). The pressure 
air arrives into a space below the pneumatic piston 25 which is then 
shifted upwards and the upper part thereof compresses (by means of a 
pressure multiplicator which is formed by step system formed by a number 
of narrowing diameters in the press-in liner 22) the hydraulic oil into 
the operating space of the hydraulic cylinder 9. The sealing O-rings 10 
and the plastic ring 11 of the hydraulic cylinder 9 prevent oil from 
leaking into the air suction space. The slide movement of the hydraulic 
cylinder 9 causes compression of the spring 17 and subsequent clamping the 
rivet shanks by the chuck collet 3. Further action of the hydraulic piston 
pressure causes rivet deformation, tightening and following fracture of 
the blind rivet shank, which shoots towards the catching box 20. 
After releasing the trigger 49 pressure air supply through the valve rod 46 
under the pneumatic piston 25 is shut off. Hydraulic pressure action onto 
the hydraulic piston 25 ceases and the spring 17 returns the same into 
initial position. Said pneumatic piston 25 is returned simultaneously into 
its initial position. 
The riveting tool can be used for connecting various parts or elements by 
riveting, especially by blind rivets.