JPS61206541A - Blind rivet clamping tool - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a housing, an abutting member having a rivet engaging surface at its front end that engages with a rivet head during a rivet caulking operation, and a means for pulling the shaft of the mandrel against the abutment member reciprocally movable within the housing, the abutment member and the mandrel tensioning means each being arranged about a common axis along which the mandrel is pulled; It has a plurality of rivet assembly engaging portions which open and close relative to the common axis to allow introduction of a mandrel with a pulling head between each engaging portion in the open state, while in the closed state. In this state, the abutment member and the rivet head are engaged, and the mandrel tensioning means is engaged with the mandrel inside the tensioning head, and further, each rivet assembly engaging portion of the abutment member and the mandrel tensioning means is in its respective open state. The present invention relates to a blind riveting tool in which a circumferentially surrounding annular actuating element resiliently biased to the periphery is arranged to close upon advancement onto a rivet assembly engaging portion of an abutment member.

(Prior Art) A blind riveting tool configured as described above is described, for example, in U.S. Pat. By also manually retracting the actuating member,
The respective rivet assembly engaging portions of the abutment member and mandrel tensioning means are opened to allow the introduction of a new rivet assembly mandrel.

Whether the tool is configured as described with reference to Figures 1 to 6 of the above specification (with the actuating member being returned to its advanced position by a spring) or as described with reference to Figures 7 to 13 However, loading a new rivet into the tool is inconvenient and slow, and the operator only has two hands to hold the tool, operate the actuating member, and load a new rivet. This is a process that actually requires three hands: pinching and inserting.

SUMMARY OF THE INVENTION It is an object of the present invention to be used for blind rivet assemblies in which the mandrel has a tensioning head, and to provide a retainer for receiving and engaging the mandrel of such rivet assemblies. An object of the present invention is to provide a blind riveting tool having a means for setting blind rivets.

(Means for Solving the Problem) According to the present invention, the actuating element is mounted in the housing so as to be reciprocally movable along a common axis behind the forward-extending sleeve portion of the housing, and The member and the mandrel tensioning means are also on a common axis between a rearward position in which they can be opened and closed after the forwardly extending sleeve portion of the housing and a forward position in which the rivet-engaging surface of the abutment member is exposed and applies the rivet to the workpiece. This is achieved by being able to reciprocate along the

Preferably, in a tool according to the invention, the actuating element in operation of the tool is configured to advance along the abutment member before the abutment member enters the forwardly extending sleeve portion of the housing, the abutment member being It remains closed as it passes through the extending sleeve section. Preferably, the forwardly extending sleeve portion of the housing has the same inner diameter as the actuating sleeve, so that during operation of the tool, the actuating sleeve is advanced to the rear end of the forwardly extending sleeve portion, and the abutment member and the mandrel tensioning means are each in a forward position. When in the rivet crimping position, the sleeve is held closed by the forwardly extending sleeve portion.

Preferably, in the tool according to the invention, pneumatic means are provided for advancing and retracting the actuating sleeve over the abutment member and for advancing and retracting the abutment member through the forwardly extending sleeve portion of the housing, the operation of the tool being Advancement of the abutment member occurs after the abutment member is closed by advancement of the actuating sleeve. Hydraulic means may also be provided for creating a relative axial displacement between the mandrel tensioning means and the abutment member to swage the rivet.

Also preferably in the tool according to the invention, the mandrel-engaging portion of the mandrel tensioning means is housed within and keyed into the rivet-engaging portion of the abutment member, and the respective mandrel-engaging portion is adapted for retraction and retraction of the abutment member. They open and close as they move forward, and their mutual axial displacement is limited by the keying means.

The forward-extending sleeve portions of the housings of the tool according to the invention have longitudinal openings in their walls, through which blind rivets can be inserted when the abutment member is in a retracted position behind the forward-extending sleeve portion of the housing. The assembly may be introduced to allow insertion of the mandrel shank between the abutment member and each open rivet engaging portion of the mandrel tensioning means. receiving the blind rivet assembly from the hose blowing it and directing the received assembly axially through the opening in the forwardly extending sleeve portion of the housing and into the open abutment member and mandrel tensioning means; A rivet assembly delivery means for this can also be provided in the housing of the tool. Furthermore, the feeding means comprises an arc-shaped tube element mounted so as to swing about the center of curvature toward an axis located along a direction perpendicular to the direction of reciprocating movement of the abutment member, and , the tubular element extends into the housing through said opening, and the delivery end of the tubular element is aligned with the open abutment member, while the other end or inlet of the tubular element is aligned with the delivery end of said hose. When aligned and in the retracted position, the tube element may be withdrawn from the path of the abutment member within the forwardly extending sleeve portion of the housing. Advancement and retraction of the tube element is effected by movement of the actuation sleeve during operation of the tool, the tool comprising rack and binion means for advancing and retracting the tube element, the rack being connected to the actuation sleeve by a free movement coupling; Movement of the tube element may occur only near the end of the back and forth stroke of the actuating sleeve.

The abutment member of the tool according to the invention consists of a sleeve with a piston at its rear end that is slidable in a hydraulic cylinder;
The sleeve has a piston at its rear end that projects forward into the sleeve of the mandrel tensioning means abutment member and is slidable in the cylinder behind the piston of the abutment member, and the sleeve has a piston at its rear end that is slidable in the cylinder behind the piston of the abutment member, and A fluid passageway is provided in the housing capable of acting rearwardly to advance the pistons and acting in front of the piston of the abutment member to retract the pistons and passing through the sleeve of the mandrel tensioning means in the vicinity of the pistons. A fluid passageway opening into the cylinder between the pistons is further provided through which pressurized fluid is introduced to separate the pistons when the pistons are at the forward end of the cylinder and to separate the pistons during operation of the tool. A rivet clinching stroke of the mandrel tensioning means can be accomplished. Such a tool includes a means for supplying pressurized air to the cylinder in front of the piston of the contact member and behind the piston of the mandrel tensioning means, and a means for supplying hydraulic oil into the sleeve of the mandrel tensioning means, and a means for supplying pressurized air to the cylinder in front of the piston of the abutment member and behind the piston of the mandrel tensioning means, and a means for supplying hydraulic oil to the sleeve of the mandrel tensioning means, and a means for supplying pressurized air to the cylinder in front of the piston of the abutting member and behind the piston of the mandrel tensioning means. may have means for guiding the material into the cylinder. A hollow cylindrical rond or sleeve extends forwardly from an end cap at the aft end of the cylinder through an annular seal in the piston of the mandrel tensioning means and terminating in an annular seal abutting an inner surface of the sleeve of the mandrel tensioning means. The hydraulic fluid conducted into the cylinder between both pistons passes through a passage in the wall of the hollow rond formed immediately behind the annular seal and an annular chamber between the hollow rond and the sleeve of the mandrel means, and passes through a passage in the wall of the hollow rond formed immediately behind the annular seal and an annular chamber between the hollow rond and the sleeve of the mandrel means. A passage through the wall adjacent to the piston can be communicated from the rear via a hollow rond. In this case, the hollow rondo is 2
With a heavy cylindrical wall, the hydraulic fluid flows through a space between the two walls sealed at each end, with the inner wall providing a passageway for rearward drainage of the broken mandrel shaft.

Hereinafter, an exemplary blind riveting tool according to the present invention will be described in detail with reference to the accompanying drawings. It will be understood that this example tool is chosen as an illustrative example and is not intended to limit the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the exemplary tool consists of a housing 10 having a rearward extension providing a pneumatic/hydraulic cylinder 12 and a front portion including a forwardly extending sleeve 14 . Housing 1
From the central body 16 of 0, a pistol-shaped grip handle 1
8 is hanging down (see also Figure 4). The central body 16 of the housing 10 has an intermediate annular wall 26 separating internal forward and rear holes 28,30, respectively, the rear hole 30 extending within the cylinder 12 and being much longer than the front hole 28.

An abutment member 50 (FIG. 1) of the exemplary tool is mounted within the housing 10 so as to be able to reciprocate along the axial direction, and the abutment member 50 is attached to an annular seal 54 (FIG. 5) within the intermediate annular wall 26. ) and having at its rear end a hollow piston 56 slidable in the rear bore 30 . A nosepiece 58 (Fig. 2.3) is screwed to the distal end of the hollow cylindrical sleeve 52, the nosepiece 58 being a hollow tonal cylinder having an inner bore terminating in a conical inner surface 60 with an obtuse apex angle. It is formed from. The outside of the nosepiece 60 terminates in a flat or hollow end surface 62 that engages the head of the rivet and is surrounded by a frustoconical surface 64. A hole 66 extends through the end wall thus formed and has a diameter sufficient to receive the shaft of the mandrel. Nose piece 58
is divided into eight arcuate segments 68 by eight slots, and these segments are expanded outward and tempered during the manufacturing process so that they are always biased to the open state by their own elasticity. It extends far back. In the open state, each tip of the dividing piece 68 that cooperates to provide the end surface 62 is
Wide enough apart to allow introduction of the mandrel pulling head. When the segments 68 are pushed toward the center and closed, each segment comes into contact with one another, creating a substantially continuous annular engagement with the head of the rivet.

Mounted inside the abutment member 50 is a second hollow piston assembly that constitutes the mandrel tensioning means 70 of the exemplary tool. At its rear end, the mandrel tensioning means 70 has a hollow piston 71 (FIG. 1.5) which is slidable in the rear bore 30 of the cylinder 12 behind the piston 56. Piston 71 is secured to a sleeve 72 that is slidable through an annular seal within piston 56 . The sleeve 72 threadably receives an adapter 74 at its front end, and the adapter 74 is threaded to receive the threaded rear end of a cylindrical collet 76 (see also FIG. 2). The collet 76 has a plurality of elastic fingers 80 formed so as to be spaced apart from each other and constantly biased against the inner wall of the split piece 68, like the split piece 68, but the inner end wall of the collet is flat. It has a frustum-shaped outer end wall that is complementary to the inner surface 60 of the nosepiece 58 . That is, each finger 8
0 has a rearward facing shoulder 82 perpendicular to the axis of the cylinder 12;
Engages the underside of the mandrel's tension head during the rivet staking action.

Since each finger 80 is constantly biased to expand by its own elasticity, it opens and closes together with the split piece 68 during operation of the tool.

The axial displacement of the tensioning means 70 within the abutment member 50 is controlled by two stepped stopper pieces 86 (the second 2 and 5). Each stopper piece 86 has a protrusion 90 housed within a wide annular groove 92 around the collet 76. Stopper pieces 86 are held within their respective slots by elastic bands 94.

The opening and closing of each segment 68 of the nosepiece 58 of the abutment member 50 and of each finger 8o of the collet 76 of the mandrel tensioning means 70 under the action of which, during operation of the exemplary tool, activates an actuating element in the form of a sleeve 100. This is done by moving back and forth respectively over the outer surface of the nosepiece. When the actuating sleeve 100 is in the rearward position (as shown in FIG. 7), the segments are free to open or expand under their own elasticity to an overall diameter greater than the diameter of the cylinder they form. be. Sleeve 100 has content that is a sliding fit with the original diameter of the nosepiece. Therefore, as the sleeve 100 moves forward past the nosepiece 58, the segments 68 move forward until they come into contact (
At the same time when the fingers 80 of the collet 76 are also pushed inward (until the slot surfaces separating the segments are parallel to each other), the mandrels are inserted between each segment 68 and between each finger 80. There is room for the head of the mandrel to be pulled into place, and when closed, each segment and finger closely surrounds the shank of the mandrel.

A sleeve portion 96 of the housing further extending forwardly therefrom is screwed into the forwardly extending sleeve 14 portion of the housing 10, the sleeve portion 96 having the same inner diameter as the actuating sleeve 100, and the abutment member 50 adapted to actuate the tool. When the sleeve 100 is advanced, it serves to keep the nosepiece 58 closed.

Actuation sleeve 100 slides within an annular seal 102 in forwardly extending sleeve portion 14 of housing 1o. The sleeve 100 has a flange 104 (constituting a piston) at its rear end. The flange 104 has an outer seal ring 1 that slides within the front hole 28 of the housing 10.
06 and an inner seal ring 107 that slides on the outer surface of the sleeve 52 of the abutment member 50.

A tube 110 projects rearwardly from the adapter 74 and provides a continuous passage therethrough for free passage into the hollow sleeve 112. The sleeve 112 has a large diameter head 11 at its front end.
4, and the large diameter head 114 has an annular seal 115 that abuts the inner wall of the sleeve 72. Sleeve 112 extends rearwardly through a seal 117 within piston 71.

The entire length of the sleeve 112 between the two bearing parts 116 (immediately behind the large-diameter head 114 in Figure 5) and 118 (Figure 8) is small in diameter, and both bearing parts support the sleeve 120. An annular chamber 122 is formed within the sleeve 120 between the sections. Sleeve 120 has an outer diameter that is smaller than the inner diameter of sleeve 72, providing an annular chamber 123 therebetween. Communication between both annular chambers 122 and 123 is provided by bearing portion 116 .
118, respectively, by a boat 124 at each end of the sleeve 120; as can be seen, the total stroke length of the piston 71 corresponds to the distance between the two boats.

Sleeve 112 is secured at its rear end to an end cap 126 mounted on cylinder 12; thus, sleeve 112 and head 114 are secured to housing 1.
Fixed within 0.

The housing 10 of the exemplary tool includes each piston 56, 71 .
Oil and air passages are provided to effect the forward and retract strokes of 104. That is, there is an inlet 130 within the handle 18 through which oil can enter and exit the end cap 126 via a tube 128. Entrance 13
The means for connecting 0 to the hydraulic amplifier is not shown in the figure and has a normal structure. Oil flows from pipe 128 to end cap 1
26 , through the boat 124 at the rear end of the sleeve 120 into the annular chamber 122 between the two sleeves 112 , 120 , and then through the boat 124 at the front end of the sleeve 120 into the sleeve 72 of the mandrel tensioning means 70 . flow inward. A boat 136 opens through the sleeve 72 just forward of the piston 71; thus, pressure oil flowing through the boat 136 into the rear bore 30 of the cylinder 12 exerts pressure on both pistons 56, 71, separating them. let When hydraulic pressure is released, oil flows in the opposite direction through the system.

The rear surface of the piston 56 and the front surface of the piston 71 are inlets 130
The piston 5 is constantly exposed to the pressure oil supplied to the piston 5.
The front surface of piston 6 and the rear surface of piston 71 are constantly exposed to air. The air is therefore supplied to the housing 10, which is provided according to normal practice in double-acting cylinders, although not detailed here.
Appropriate boats 156 (Fig. 6), 158 (Fig. 8) within
and passages into and out of the front and rear parts of the cylinder 12.

The operation cycle of each part of the rivet crimping part of the exemplary tool is as shown in FIG. It is most convenient to consider starting from the respective forward positions as shown in FIG. 7; the blind rivet assembly is shown in FIG. 7 as it is fed into the nosepiece. The nosepiece 58 projects slightly from the sleeve portion 96 of the housing 10 and is kept closed by its longitudinal extension. Each segment and finger tightly surrounds the mandrel M and the mandrel does not fall out due to their shoulders overlapping the pulling head P of the mandrel.

A means for controlling the flow of air and hydraulic oil to sequentially operate each part of the tool is schematically shown in FIG.

When the tool is at rest, as shown in FIG. Inflow. In other words, the piston 56
The abutment member 50 is held within the housing in its forward-most position by pressurized air in the cylinder 12 behind the piston 71 in contact with the abutment member 50, and the oil pressure at the inlet 130 is atmospheric pressure.

The air behind the actuation sleeve 100 is also under pressure.

The tool is now applied to the workpiece (not shown), the rivet l-R is inserted into the hole in the workpiece, and the rivet head is pressed against the workpiece by the nosepiece 58. The handgrip 18 is provided with a push button switch of the electric control circuit, and when the operator presses this switch, the solenoid valve 206 in the hydraulic circuit is energized, and the pressure multiplier 208 is activated.
Pressure oil from the inlet 130 is introduced into the cylinder 12 between the two pistons 56, 71. At the same time, the two-position valve 20
2 is energized and immediately opens a passage for exhausting the air behind the piston 71. The pressure oil forces the pistons 56, 71 apart and crimps the rivet by pulling the mandrel while pressing against the rivet head; the mandrel eventually breaks at the neck of the rivet where the cross-section of the mandrel shank is reduced, and the mandrel If the broken portion of the shaft M (shown in FIG. 5) is not retained between the fingers 80 by friction, it will be ejected rearwardly along the tube 110 and sleeve 112 and into a suitable receptacle through the hose 150. Go inside. The separation between pistons 56 and 71 is provided by slot 88 and stopper piece 8.
6. The tool is now in the state shown in Figure 6. Preferably, for example, the receiver reduces the air pressure in the vessel and generates suction through the hose, allowing the air to flow slowly and continuously backwards along the tube, sleeve and hose to facilitate evacuation of the mandrel shaft. do.

Activation of valve 202 opens forward hole 28 behind sleeve 100 to vent exhaust and pressurizes airline 210 leading to the front of cylinder 12. However, at this point, the piston 56 cannot move back, since the tensioning means 70 is held in front by the mandrel. However, when the mandrel breaks, the piston 56 moves backward and the piston 71
Press backward. After a preset time delay in the electrical control circuit, the solenoid valve 206 is deenergized and the spring pressure causes the pressure oil to flow back out of the cylinder 12 between the pistons 56 and 71. When piston 71 reaches the rear end of its stroke, it engages spring-loaded plunger 212 of valve 214 and directs pressurized air from line 210 into forward hole 28 in the front of piston 104 and retracts actuating sleeve 100. At the same time, the split piece 68 of the nosepiece 58 and the finger 80 of the mandrel tensioning means 70 are opened (see FIG. 7),
If the broken mandrel shaft has not yet been released,
Release it and eject it behind the tool.

As explained below, for the complete operating cycle of the example tool:
Here, the new blind rivet assembly is attached to nose piece 5.
8 and fingers 80, the actuating sleeve 100 is advanced by reversing the air pressure in the forward hole 28;
While closing the dividing piece 68 and the finger 80, the piston 7
By introducing air into the rear hole 30 behind the rivet 1, the abutting member 50 and the mandrel tensioning means 70 move forward, returning the rivet crimping parts to the state shown in FIG.

The advancement of the sleeve 100 and both pistons 56 and 71 is caused by the valve 2
This is accomplished by deenergizing the solenoid 02 and switching the diverter valve 202, which occurs a predetermined amount of time after pressing the pushbutton 148, set by a time delay in the electrical control circuit. However, the forward movement of both pistons 56 and 71 is
Since a valve 204 is interposed in the line following the rear of the cylinder 12, after the sleeve 100 moves forward, the piston 56
The valve 204 is delayed until the front pressure decreases to open the cylinder 12 behind the piston 71. Thus, regardless of whether the operator releases push button 148, the tool returns to the state shown in FIG. 1, but the second cycle does not begin until the operator releases push button 148 and presses it again.

The means of the exemplary tool for loading a new bed assembly into the mandrel pulling means 70 while the abutment member 50 is retracted will now be described. The assembly feeding structure itself is the subject of the applicant's pending German patent application no. P3444025.

The sleeve portion 14 of the housing 10 of the exemplary tool has a flat depending extension 160 (FIGS. 4.5 and 7) on the side.
, one side 162 of which is integral with the sleeve portion 14,
The other side forms a cover 164.

The image portions 162, 164 support a rotatable lateral pivot pin 166 with a pinion 16 attached to the pivot pin 166.
8 is fixed. The pinion 168 is mounted on a rack 170 that is vertically reciprocatable below the sleeve 100 in a bearing 172 provided by the sleeve portion 14 of the housing.
engage with. Rank 170 has teeth along its lower edge that mesh with the teeth of pinion 168 . Vertical slot 17
4 extends along the rear of the rack and is moved within the slot 174 by a pin 176 secured to a lug 178 depending from a collar 177 screwed to the sleeve 100.

A bracket 180 is fixed to the pinion 168 so as to be able to rotate back and forth integrally therewith, and the pinion 16 is attached to the bracket 180.
It is fixed to a curved tube 182 concentric with 8. By the stroke of the sleeve 100 or by the bracket 1
When the piston swings clockwise to the limit (shown in FIG. 7) provided by stop surface 184 of 80 engaging stop surface 186 of depending extension 160, the delivery end of curved tube 182 Housing sleeve part 9
6 through the opening 187 of the nosepiece 58 and is aligned with the split piece 68 of the nosepiece 58 in close alignment with the split piece. Moreover, when the curved pipe 182 is in the above-mentioned delivery position,
The other end or inlet of the tube is aligned with the delivery end of a hose 192 extending from the supply of blind rivet assemblies. Means for releasing the blind rivet assemblies releases one assembly at a time with the pulling head of the mandrel facing forward and each assembly when the bend tube 182 is in its delivery position (FIG. 7). (one shown) is blown along hose 192 to load each assembly into a mandrel tensioning means, which will not be further described here. As shown in FIG. 7, the inlet end of the curved tube 182 and the outlet of the hose 192 have opposing ends that are curved in a complementary manner to allow each assembly to pass from the hose to the curved tube across a minimal gap. It is said that

Stopper surface 188 of bracket 180 and hanging extension portion 16
When the nion 16B swings counterclockwise (see FIG. 5) into engagement with the stopper surface 190 of 0 or the other limit of movement given by the stroke of the actuating sleeve 100, the delivery end of the curved tube 182 is the contact member 50
The abutment member 50 is then advanced as described above to prepare the tool for the next blind riveting operation.

Bracket 180 and bending tube 1 during the operating cycle of the exemplary tool
82, a torsion spring 194 (FIG. 4) acts between the depending extension 160 of the housing and the pin 166 to which the pinion 168 is fixed.
The bracket 180 (in FIG. 7) is biased clockwise. The slot and bin combinations 174 , 176 allow movement to occur between the actuating sleeve 100 and the rack 170 during the initial advancement of the actuating sleeve 100 and the curved tube 18
2 leaves its delivery position, the segment 58 and fingers 80 close to provide control over the newly delivered blind rivet assembly.

[Brief explanation of the drawing]

FIG. 1 is a side view, partially in longitudinal section, of an exemplary tool, the tool being loaded with a blind rivet assembly;
The tool is ready to be applied to the workpiece for a blind riveting operation; FIG. A partial cross-sectional view; FIG. 3 is a transverse sectional view taken along line mm in FIG. 2; FIG. 4 is a transverse sectional view taken along line IV-IV in FIG. 5; 5.6 and 7 are views similar to FIG. 1, but showing parts of the tool at successive stages in the operating cycle of the example tool, with the rear portion of the tool omitted in each of these views; FIG. A view mainly showing a cross-section of the rear part, showing each part in the position occupied at the stage shown in Figs. 6 and 7;
and FIG. 9 is a circuit diagram of the fluid control means of the tool. 10...Housing, 12...Fluid pressure cylinder, 5
0... Contact member, 52... Sleeve, 56...
Piston, 62... Rivet engaging surface, 68... Rivet assembly engaging portion of contact member, 70... Mandrel tensioning means, 71... Piston, 72... Sleeve, 80 ...Rivet assembly engagement part, 96...
Front extending sleeve portion, 100... Actuation element (warp), 122, 123, 124, 136, 156.158
...Flow path, 1B2...Rivet assembly feeding means, 1
87...Opening, 192...Hose, B...Blind rivet assembly, R...Rivet 7, M...Mandrel, P...Tension head. (L-co-&J-L-C7”)

Claims (1)

[Scope of Claims] 1. A housing, a contact member having a rivet engaging surface at its front end that engages with the head of the rivet during the rivet crimping operation, and a contact member capable of reciprocating within the housing during the rivet crimping operation. means for tensioning the shank of the mandrel against the mandrel, the abutment member and the mandrel tensioning means each having a plurality of rivet assembly engaging portions disposed about a common axis along which the mandrel is tensioned; These rivet assembly engaging parts open and close with respect to the common shaft, and in the open state, the mandrel with a tension head can be introduced between the respective engaging parts, while in the closed state, the abutment member and the rivet head can be inserted. and the mandrel tensioning means and the mandrel inside the tensioning head are engaged, and the rivet assembly engaging portions of the abutment member and the mandrel tensioning means are elastically biased to their respective open states and surround the outer periphery. A blind riveting tool in which an annular actuating element is arranged to be closed by advancement onto a rivet assembly engaging portion of an abutment member, the actuating element being arranged along a common axis behind a forwardly extending sleeve portion of the housing. The abutting member and the mandrel tensioning means are also placed in a rearward position where they can be opened and closed after the forward extending sleeve portion, and the rivet engaging surface of the abutting member is exposed to allow the rivet to be pulled. A blind riveting tool characterized in that it is capable of reciprocating along a common axis between a forward position applied to a workpiece and a forward position. 2. The forward-extending sleeve part of the housing has the same inner diameter as the sleeve of the actuating element, and when the tool is operated, the actuating sleeve advances to the rear end of the forward-extending sleeve part, and each rivet set of the abutting member and the mandrel tensioning means closing the body-engaging portions prior to their advancement, and each rivet assembly-engaging portion of the abutment member and mandrel tensioning means being held closed in their respective advanced positions by said forwardly extending sleeve portion of the housing. The tool according to claim 1, characterized in that: 3. The forward extending sleeve portion of the housing has an opening in its wall, and when the abutment member is in a retracted position behind the forward extending sleeve portion of the housing, the blind rivet assembly is introduced through the opening. 2. A tool according to claim 1, wherein the shank of the mandrel is insertable between the abutment member and each open rivet assembly engaging portion of the mandrel tensioning means. 4. Rivet assembly delivery for receiving the blind rivet assembly from its blowing hose and directing the received assembly axially through an opening in the forward extension of the housing to the open abutment member and mandrel tensioning means; 2. A method as claimed in claim 1, characterized in that the means are provided in the housing of the tool. 5. The abutment member comprises a sleeve with a piston at the rear end that is slidable within the hydraulic cylinder, and the mandrel tensioning means projects forward into the sleeve of the abutment member and is located behind the piston of the abutment member as described above. It consists of a sleeve having a piston at its rear end that is slidable within the cylinder, and pressurized fluid is applied to the rear of the piston of the mandrel tensioning means to advance both pistons, and the pressurized fluid is applied to the front of the piston of the abutment member to advance both of the pistons. A fluid passageway is provided in the housing through which the piston can be retracted, and a fluid passageway is further provided which passes through the sleeve of the mandrel tensioning means near the piston and opens into the cylinder between the pistons, through which both the pistons can be retracted. A tool according to claim 1, characterized in that pressurized fluid is introduced when the piston is at the front end of the cylinder to separate the pistons and effect a riveting stroke of the mandrel tensioning means during operation of the tool. .