Automatic rivet feed

A device for setting a blind rivet is provided with an automatic rivet loading means. The rivet is fed through a rivet feeding pipe to the device and a parallel crank mechanism and slider cooperate to transport the rivet to the jaws of the setting tool.

BACKGROUND OF THE INVENTION 
This invention relates to a device for fastening a blind rivet which has a 
rivet body and a mandrel axially extending rearwardly from the rivet body, 
and more specifically, to an automatic rivet loading device for use in 
such a device. 
Ordinarily, a blind rivet fastener is used in such a manner that the 
mandrel of a blind rivet is inserted in a hole of a nose piece provided at 
the tip end of a nose housing forwardly projected from a fastener body, 
and is grasped by jaw means in the nose housing to be forcedly pulled 
rearwardly so as to set the rivet. In such a situation, it will be greatly 
convenient if the rivet is automatically loaded into the nose piece. 
For this purpose, different automatic rivet loading devices have been 
heretofore proposed. For example, Japanese Patent Public Disclosure Sho 
No. 52-79379 discloses a device having a chuck support mounted on a nose 
housing movable only in a longitudinal direction. The chuck support 
rotatably holds a chuck body. The chuck support is adapted to be 
longitudinally moved by air cylinder means mounted on the device body. The 
chuck body has chucking pawls at its tip end. When the chuck support is in 
the rearmost position, the discharging end of a rivet supplying pipe 
mounted on the body is brought into alignment with the rear end of the 
chuck body to feed a rivet to the chuck pawls by pressurized air, and the 
rivet is held by a holding pawl. Thereafter, the chuck support is 
forwardly moved by the air cylinder means to its forwardmost position 
where the chuck body is downwardly swung through a lever by means of the 
air cylinder so as to align the chuck with the nose piece, and the chuck 
support is rearwardly moved a short distance to insert the mandrel of the 
rivet into the hole of the nose piece. 
In the construction disclosed by the aforementioned Japanese Patent Public 
Disclosure Sho No. 52-79379, since the chuck body is pivotally mounted for 
only rotational movement against one straight pipelike chuck support, when 
the chuck body is downwardly swung at the front of the nose piece, in 
order to ensure that the rivet holding hole of the chuck pawls is brought 
into alignment with the hole of the nose piece, the feeding hole of the 
chuck body is angled to the rivet holding hole of the chuck pawls. This is 
apt to prevent the rivet from being surely fed to the chuck, and, when the 
pressure of the pressurized air is low, the rivet has a tendency to be 
caught by a bent portion. In addition, it is so arranged that the diameter 
of the holding hole of the chuck is made slightly larger than the outer 
diameter of the rivet body to facilitate the feeding of the rivet through 
a bent path to the chuck. It is for this reason that the holding pawl is 
provided. But, this holding pawl is not only an obstacle to rivet feeding 
but also is not sufficient to stably hold the rivet in the holding hole of 
the inner diameter larger than the outer diameter of the rivet. Further, 
since the rivet holding hole is at an angle to the inner path in the chuck 
body, a delicate adjustment is required to bring the rivet holding hole 
into alignment with the nose piece hole by the downward swing of the chuck 
body. 
Accordingly, it is an object of this invention to provide a rivet loading 
device of simple construction which is capable of securely holding a rivet 
by a chuck and of securely and easily loading the rivet to a nosepiece. 
SUMMARY OF THE INVENTION 
To accomplish the various objects of the invention, a device is provided 
for setting a blind rivet of the type having a rearwardly projecting 
mandrel which device includes a body, a nose housing extending forwardly 
from the body, a nose piece mounted on a tip end of the nose housing and 
having an axial through-hole for reception of the mandrel of the blind 
rivet, and a jaw device located in the nose housing. 
The device is characterized in that it comprises a slider mounted on the 
nose housing to be slidable only in its longitudinal direction, and two 
arm members are pivotally mounted at one end thereof on separate points of 
the slider and extending forward from the slider. A chuck holder is 
pivotally connected at separate points thereof to the other ends of the 
arm members, respectively, the chuck holder operating in cooperation with 
the arm members and the slider to constitute a parallel crank mechanism, 
and a rivet feeding means is mounted on the body and extends in parallel 
relation to the nose housing. The feeding means has a discharging end 
having an axial line in parallel to the axis line of the through hole of 
the nose piece. A chuck member is mounted on the chuck holder and has a 
rivet receiving hole having a longitudinal axis line in parallel to the 
axis line of the rivet feeding means and is adapted to resiliently hold 
the received rivet. Means is mounted on the body acting to longitudinally 
slide the slider on the nose housing and an abutting member is provided on 
the chuck holder and acts, when the slider is at the rearmost position, to 
ceaselessly engage with a peripheral surface of the nose housing so as to 
hold the parallel crank mechanism at an upwardly swung position while 
bringing the rivet receiving hole of the chuck member in alignment with 
the discharging end of the rivet feeding means. A lever means is provided 
on the slider and acts when the slider is at the foremost position on the 
nose housing, to downwardly swing the parallel crank mechanism in response 
to a retracting action of the means for sliding the slide so as to bring 
the rivet receiving hole of the chuck member into alignment with the 
through-hole of the nose piece.

DESCRIPTION OF A PREFERRED EMBODIMENT 
Referring to FIGS. 1 and 2, a blind rivet fastener includes a body 2 having 
a trigger 1 and a nose housing 3 projected forwardly from the body. The 
nose housing 3 has a jaw device 4 located therein which is well-known in 
the art. The nose housing 3 also has a nose piece 5 provided at a tip end 
thereof and having a through-hole 6. A mandrel 25A of a rivet inserted 
into the through-hole 6 is rearwardly pulled to set the rivet. This 
operation is initiated by triggering the trigger 1, as well-known. Since 
this construction is not included in this invention, more detailed 
description is omitted here. 
A slider 7 is slidably mounted around the nose housing 3. The slider 7 is 
slidably only in the longitudinal direction of the nose housing 3 because 
of a key 8 and therefore is nonrotatable therearound. 
The slider 7 has an upwardly projecting portion 9 whose tip end is 
pivotably mounted on one end of an arm 11 by means of a pin 10. A coil 
spring 12 is located around the pin 19 and is engaged at its one end with 
the arm 11 and at its other end with the slider 7 so as to continuously 
urge the arm counterclockwise. 
Another arm member 13 is pivotably mounted at its one end by a pin 14 on 
the slider 7 apart from the pivotally mounted point of the arm 11. The arm 
member 13 consists of two arms 15 which extend in parallel to each other 
to position the slider 7 therebetween and extend forward from the slider 
in parallel to the arm 11. The arm 11 and the arm member 13 are pivotally 
mounted at their other ends on a chuck holder 18 by pins 16 and 17, 
respectively, having the same interval as that between their pivotally 
mounted points on the slider. Therefore, the arms, the slider and the 
chuck holder constitute a parallel crank mechanism 20 which can vertically 
move the chuck holder 18 keeping the vertical attitude of the holder as 
shown in the drawing. 
The chuck holder 18 supports the chuck member 21 which includes two 
symmetrical L-shaped portions 22 biased toward each other by compressed 
coil springs 23. Each of the L-shaped portions 22 has a forward hole 26 
formed at a lower portion thereof to receive a body portion 25 of a rivet 
24. In succession with the forward hole, a backward hole 27 is formed to 
have an inner diameter made gradually larger toward the rear. The backward 
hole 27 has a notch 28 provided at its lower rear end. 
The chuck holder 21 has a downwardly extending abutting member 29 provided 
at its front surface. When the slider 7 is in the rearmost position, the 
abutting member is in engagement with the surface of the nose housing 3 to 
hold the parallel crank mechanism 20 in an upwardly swung position as 
shown in FIGS. 1 and 2 against the force of the spring 12. 
Above the body 2, a rivet feeding pipe 30 is secured to have its 
longitudinal axis in parallel relation to the axis of the nose housing 3, 
i.e., to the axis of the through-hole 6 of the nose piece 5. The feeding 
pipe 30 has a discharging end 31 projecting forwardly therefrom. When the 
parallel crank mechanism 20 and the slider 7 are in the position as shown 
in FIGS. 1 and 2, the backward hole 27 of the chuck 21 is caused to engage 
with and surround the discharging end 31. The rivet feed pipe is connected 
at its rear end to a rivet supplying mechanism as well-known in the art. 
Therefore, if a blind rivet 24 is fed through the rivet feeding pipe 30 by 
pressurized air in a well-known manner with a mandrel 25 of the rivet 24 
being at the rearward position, since the rivet receiving hole 27 of the 
chuck 21 is in alignment with the discharging end 31 of the rivet feeding 
pipe 30, the rivet is surely and easily inserted in its original attitude 
into the rivet holding hole 26 of the chuck 21 against the force of the 
spring 23 and consequentially is resiliently held there. 
An air cylinder device 34 is located at a side of the body 2. A rod 35 of 
the cylinder device is coupled with the slider 7 through an L-shaped lever 
36. The L-shaped lever 36 is pivotally mounted at its intermediate portion 
on the slider 7 by means of a pin 14. The lever 36 has a lateral support 
pin 37 at a front end thereof. The support pin 37 is adapted to engage 
with the lower surface of the arm member 13. The lever 36 is coupled at a 
rear end 38 thereof with the rod 35 of the air cylinder device 34 and is 
positioned between two stops 40 and 41. When the air cylinder device 34 is 
operated to protrude the rod 35, the lever 36 is first rotated to engage 
with the stop 40. 
With further protrusion of the rod 35, the slider 7 is caused to slide 
forward on the nose housing 3. It will be noted that while the slider 7 is 
moving forward the support pin 37 of the lever 36 continuously holds the 
parallel crank mechanism in the position as shown in FIGS. 1 and 2. 
In such a position, the slider 7 continues to move forward and reaches the 
foremost position as shown in FIG. 3. The chuck 21 is positioned in 
advance of the nose piece 5 while being in alignment with the discharging 
end 31 of the rivet feeding pipe 30. 
In the condition as shown in FIG. 3, if the rod of the air cylinder device 
34 is pulled back, the parallel crank mechanism 20 is swung downwardly by 
the action of the spring 12. Because of the parallel crank mechanism, the 
chuck holder 18 is moved downward in advance of the nose piece 5 in the 
vertical attitude, i.e., keeping the rivet holding hole 26 of the chuck 21 
in parallel with the through hole 6 of the nose piece 5. At the same time, 
the lever 36 is rotated counterclockwise by the support pin 37 so that the 
rear end of the lever is engaged with another stopper 41. At this time, 
the rivet holding hole of the chuck 21 is brought into alignment with the 
through hole 6 of the nose piece 5 as shown in FIG. 4. As mentioned above, 
this is because the axis of the rivet feeding pipe 30 is parallel with the 
axis of the nose piece 5. Since the operation of the parallel crank 
mechanism is simple as stated hereinbefore, positional adjustment of the 
stoppers 40 and 41 is simple and easy, and it is easy to bring the chuck 
21 into alignment with the rivet feeding pipe 30 and the nose piece. 
Thereafter, the air cylinder device 34 is operated to retract the rod 35 so 
that the slider 7 and hence the chuck 21 is moved back to insert the 
mandrel 25A of the rivet into the through-hole 6 of the nose piece 5, 
whereby the mandrel 25A is grasped by the jaw device 4 and the chuck 21 is 
engaged with the nose piece 5. With further retracting operation of the 
air cylinder device 34, since the chuck 21 has the notch 28, the empty 
chuck which has delivered the rivet 24 to the jaw device 4 is caused to 
pass over the nose piece 5 as it is and is moved backward in engagement 
with the nose housing 3. With further retraction of the slider 7, the 
abutting member 29 of the chuck holder 18 is finally engaged with the top 
portion of the nose housing 3 and then acts to return the parallel crank 
mechanism 20 to the position shown in FIGS. 1 and 2 against the pushing 
force of the spring 12 and the air pressure in the air cylinder device 34. 
At the same time, the chuck 21 is engaged with the discharging end 31 of 
the rivet feeding pipe 30 so that it is ready for receiving the next 
rivet. Means may be separately provided to upwardly guide the chuck holder 
18 at the time of the backward movement of the slider 7. 
The above mentioned operation is accomplishable by manipulating the trigger 
to operate a sequence circuit obvious to a person skilled in the art. 
According to this invention, a blind rivet can be received into and 
securely held with a chuck without hindrance, and can be securely and 
easily loaded to a nosepiece. In addition, such operation is performed by 
a simple mechanism.