EP0338406A2

EP0338406A2 - Automatic self-advancing machine for applying inserts

Info

Publication number: EP0338406A2
Application number: EP89106536A
Authority: EP
Inventors: Mario Zucchelli
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-04-20
Filing date: 1989-04-12
Publication date: 1989-10-25
Also published as: IT8820265A0; EP0338406A3; IT1216607B

Abstract

Self-advancing automatic machine for applying inserts, including an internally hollow body (1) which is closed at one end by a bottom (2) and, at the other end, by a dome (3) associated with an insert-holder head (5). An active element (10) is accommodated in said body and a tool (11) is connected thereto. The peculiarity of the invention resides in the fact that it comprises, inside the body, a first chamber (20) which is defined in the portion proximate to the bottom and in which an advancement piston (21) is movable and is associated with the active element, and a second chamber (30) in the portion proximate to said dome, in which a positioning piston (31) is sealingly movable and is adapted to interact with the active element (10). A first inlet (40) is furthermore provided in the bottom for the passage of pressurized fluid in the first chamber and so is a second inlet (45) in the dome for the passage of pressurized fluid in the second chamber. Valve means (50) are furthermore provided and control the passage of fluid from the second chamber for the controlled translatory motion of the active element.

Description

The present invention relates to a self-advancing automatic machine for applying inserts.
Previous patent applications in the name of the same Applicant (application no. 24572 A/82 filed on December 2, 1982 and application no. 23465 B/83 filed on November 7, 1983), described an automatic machine for applying inserts such as nails, bolts, screws, rivets and the like; said machine had a hollow body inside which an active element was accommodated by interposing means adapted to prevent its rotation; said active element caused the tool to advance and provided its actuation, constituted by its rotation in the case of a screwer, or any other kind of actuation according to the insert being used.
In one of the described embodiments, valve means were used to position and move the active assembly; said valve means selectively connected the active assembly to a source of low-pressure fluid and to a source which delivered a fluid at high pressure. The described embodiment comprised channels in the jacket of the body, and said channels allowed the communication of the pressurized fluid in order to controllably move the active element.
The other embodiment comprised an active element provided with a flexible tube for feeding the fluid at high pressure and moving sealingly and coaxially to the air feed duct.
Both embodiments furthermore comprised elastic means constituted by adjusted springs which positioned the advancement element in the initial step after the insert had been fed and before it was applied.
Though the described embodiments are valid from every functional and conceptual point of view, they are susceptible to improvements, especially with regard to the means for positioning the active element in the initial work step, i.e. in the step in which the tool engages the insert which has been fed.
The aim of the invention is indeed to provide an improved self-advancing automatic machine which comprises extremely safe and effective means for positioning the active element, structured so as to considerably simplify the construction of the tool.
Within the scope of the above described aim, a particular object of the invention is to provide an automatic machine in which all the connections are simplified and which allows exclusively automatic operation, with the possibility of being used on lines for the automatic application of inserts and as a portable tool.
A further object of the present invention is to provide an automatic machine which by virtue of its peculiar constructive characteristics is capable of giving the greatest assurances of reliability and safety in use.
Not least object of the present invention is to provide a self-advancing automatic machine for the application of inserts which can be easily obtained starting from elements and materials commonly commercially available and is furthermore competitive from a merely economical point of view.
This aim, the objects mentioned and others which will become apparent hereinafter are achieved by a self-advancing automatic machine for the application of inserts, according to the invention, comprising an internally hollow body which is closed at one end by a bottom and at the other end by a dome associated with an insert-holder head, said body accommodating an active element with which a tool is connected, characterized in that it comprises, inside said body, a chamber defined in the region proximate to said bottom, an advancement piston being associated with said active element and being sealingly movable in said chamber, and a second chamber, in the region proximate to said dome, in which a positioning piston is sealingly movable and is adapted to interact with said active element, said bottom furthermore comprising a first inlet for the passage of pressurized fluid to said first chamber and a second inlet in said dome for the passage of pressurized fluid in said second chamber, valve means being furthermore provided, said means controlling the passage of fluid from said second chamber for the controlled movement of said active element.
Further characteristics and advantages will become apparent from the description of two preferred but not exclusive embodiments of a self-advancing automatic machine for applying inserts, illustrated only by way of non-limitative example in the accompanying drawings, wherein:

figure 1 is a sectional view of a machine in its initial position, in which the insert is also illustrated;
figure 2 is a sectional view of a machine, in which the insert is also illustrated, after the tool has been positioned on the insert;
figure 3 is a sectional view of a machine, in which the insert is also illustrated, during the step of application of said insert, which is constituted by a screw in the specific case;
figure 4 is a view of an automatic machine according to a further aspect of the invention in its initial condition;
figure 5 is a view of the machine of figure 4 in the positioning step, in which the tool and the insert are mutually engaged;
figure 6 is a schematic sectional view of the automatic machine of figures 5 and 6 during the machine's operation.

With reference to the above described figures, and in particular to figures 1 to 3, the self-advancing automatic machine for applying inserts, according to the invention, comprises an internally hollow body 1 which preferably has a substantially elongated cylindrical configuration.
At one axial end, the body 1 is closed by a bottom 2, while at its opposite end said body 1 is closed by a dome 3 which defines a seat 4 for coupling to an insert-holder head 5 of a per se known type. According to what is illustrated in figures 1 to 3, the head 5 has clamps 6, also of a known type, for the visual positioning of the insert 7, which is constituted by a screw in the specific example but can naturally be constituted by any other kind of insert to be applied.
An active element 10 is inserted inside the body 1, and a tool 11 is connected thereto; said tool can be moved to engage the insert 7 as will become apparent hereinafter.
Anti-rotation means act between the active element 10 and the cavity in which said element is accommodated; said means are constituted by a ring l2 which is associated with the active element 10 and cannot rotate; said ring has, for example, lugs l3 which engage in longitudinal grooves 14 defined in said cavity.
The important peculiarity of the invention resides in the fact that a first chamber 20 is defined inside the cavity in the portion proximate to the bottom 2, and an advancement piston 21 is sealingly movable in said chamber 20 and is associated with the active element 10; a second chamber 30 is defined in the region affected by the dome 3, and a positioning piston 31 is sealingly movable in said second chamber 30 and has an axial tang 32 through which the tool 11 can pass; said tang sealingly engages an annular gasket 33 which closes the chamber 30 in the portion directed toward the seat 4 where the insert-holder head has been provided.
The first chamber 20 has a first inlet 40 connected to a source of pressurized fluid, preferably compressed air, which moves the piston 21 and consequently moves and actuates the active element 10, as will become apparent hereinafter. The second chamber 30 is connected to a second inlet 45 which is also connected to a source of pressurized fluid by interposing valve means which control the passage of fluid so as to adjust the advancement and the positioning of the active element 10.
One-way valve means, generally indicated by the reference numeral 50, are provided on the piston 21 and are actuated by an axial stem 51 connected to the axial motion of the tool 11 so as to connect the active element 10 to the pressurized source.
Venting holes 60 are provided in the cavity defined by the body 1 for the exit of the air which has actuated the active element 10. A sensor, schematically indicated by 61, can be connected on one of the holes and has the function of detecting the outflow of pressurized air and of consequently driving the control valve means of the inlet 45 to allow the outflow of the air from the second chamber 30 and the consequent advancement of the active element 10 and of the tool 11 connected thereto.
In practical operation, the insert 7 is fed into the insert-holder head 5 in a per se known manner as indicated in figure 1.
In these conditions, when compressed air is fed into the first chamber 20, there is a first step of advancement of the active element 10 until it abuts against the piston 31. In these conditions the active element 10 and therefore the tool 11 stop at preset positions, since the first and second chambers are fed with a fluid which has, for example, the same pressure; the stop occurs because the useful cross section of the second chamber is greater than the useful cross section of the first chamber. The second piston consequently remains in its initial position, which is advantageously defined by an abutment 31a which is provided by the coupling of the dome 3 with the body 1, which has a smaller diameter.
When the active element is in its work start position, the tool is engaged with the insert 7, which is visible.
By exerting a compression action axially to the insert, the translatory motion of the stem 51 opens the one-way valve 50, consequently feeding fluid from the first chamber 20 into the active element 10, which consequently starts operating and, in the specific example of a screwer, is rotated.
The pressurized fluid which flows out of the active element 10 is discharged outside through the discharge holes or ports 60; the sensor arranged on one of said ports is capable of detecting the flow of air and consequently actuates a control which allows the adjustable outflow of the pressurized fluid from the second chamber 30; the active element 10 therefore advances, since the contrast exerted by the piston 31 ceases or in any case decreases, allowing the self-advancement of the tool until the required screwing is performed.
In the specific illustrated example, the advancement of the active element is started by the sensor detection; a separate control may naturally be provided to actuate the outflow of the compressed air from the second chamber 30 so as to consequently allow the active element to advance.
With reference to the embodiment illustrated in figures 4 to 6, a self-advancing automatic machine is provided in which the insert is not visible. All the previously described elements are conceptually and structurally provided, with the variation that an external actuation lever 70 is provided and acts on a switch button 71 which opens the valve means for the outflow of the air from the second chamber, again indicated by 30.
In this case, when the lever 70 is actuated, the active element is advanced and continues to advance until the tool 11 makes contact with the insert, again indicated by the reference numeral 7; upon contact with the insert, an axial translatory component is obtained which opens the one-way valve means and consequently allows the inflow of pressurized fluid into the active element 10 and consequently actuates it.
In this second embodiment, pressurized fluid may always be present in the first chamber, and the advancement step is performed by means of the outflow of compressed air from the second chamber, while the step of return to the initial position is obtained by re-introducing pressurized fluid into the second chamber; in this specific example, the active element is always in contact with the positioning piston 31.
In the embodiment illustrated in figures 1 to 3, the return step, i.e. the active element's return, to its initial position is obtained by means of a return spring, indicated by 80, which acts between the anti-rotation ring 12 and the piston 31, and the active element can return only if the pressure is removed from the first chamber 20.
From what has been described above it can thus be seen that the invention achieves the proposed aim and objects and in particular the fact is stressed that the structure of the automatic machine is considerably simplified; in said machine, compressed air is fed directly into a first chamber arranged in its rear portion and into a second chamber arranged in its front portion, without having to resort to complicated constructive solutions.
This simplification is allowed by the presence of the positioning piston, which is capable of stopping the initial advancement of the active element by using the same compressed air which is used to advance and actuate the active element and by creating a difference in useful cross section, i.e. by providing a positioning piston chamber which has a greater cross section than the advancement piston chamber.
The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept.
All the details may furthermore be replaced with other technically equivalent elements.
In practice, the materials employed, so long as compatible with the specific use, as well as the dimensions and the contingent shapes, may be any according to the requirements.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims

1. Automatic self-advancing machine for applying inserts, comprising an internally hollow body (1) closed at one end by a bottom (2) and at the other end by a dome (3) associated with an insert-holder head (5), an active element (10) being accommodated in said body, a tool (11) being connected to said active element, characterized in that it comprises, inside said body, a first chamber (20) which is defined in the portion proximate to said bottom (2) and in which an advancement piston (21) associated with said active element is sealingly movable, and a second chamber (30), in the portion proximate to said dome, in which a positioning piston (31) adapted to interact with said active element is sealingly movable, said machine furthermore comprising a first inlet (40) in said bottom (2) for the passage of pressurized fluid into said chamber (20) and a second inlet (45) in said dome (3) for the flow of pressurized fluid into said second chamber (30), as well as valve means (50) which control the flow of fluid from said second chamber for the controlled translatory motion of said active element.

2. Automatic machine, according to the preceding claim, characterized in that said second chamber (30) has a greater useful cross section than that of said first chamber (20).

3. Automatic machine, according to the preceding claims, characterized in that said positioning piston (31) has an axial tang (32) inside which said tool (11) passes, said tang slidably and sealingly engaging sealing means (33) which separate said chamber (30) from the application seat (4) of said insert-holder head.

4. Automatic machine, according to one or more of the preceding claims, characterized in that it comprises abutment means (31a) for positioning said positioning piston (31), said means being defined by the coupling between said dome (3) and said body (1).

5. Automatic machine, according to one or more of the preceding claims, characterized in that it comprises, in said advancement piston (21), one-way valve means (50) which can be actuated by the translatory motion of a stem (51) which passes axially in said active element (10), said one-way valve means controlling the passage of pressurized fluid from said first chamber (20) to said active element.

6. Automatic machine, according to one or more of the preceding claims, characterized in that it comprises, on said body, venting holes or ports (60) for the outflow of the actuation fluid of said active element (10), a sensor (61) being provided on at least one of said holes, said sensor driving the valve means which control the outflow of the pressurized fluid from said second chamber (30).

7. Automatic machine, according to one or more of the preceding claims, characterized in that it comprises a spring (80) for returning said active element (10) to its position, said spring interacting between an anti-rotation ring (12), interposed between the cavity defined inside said hollow body (1) and said active element, and said positioning piston (31).

8. Automatic machine, according to one or more of the preceding claims, characterized in that it comprises a lever (70) which is associated with said body and interacts with a switch button (71) which drives said valve means (50) which control the outflow of the pressurized fluid from said second chamber (30).