EP0195851B1

EP0195851B1 - Installing tool for wedging-type fasteners

Info

Publication number: EP0195851B1
Application number: EP85115158A
Authority: EP
Inventors: Victor Belanger
Original assignee: MAG Aerospace Industries LLC
Current assignee: Monogram Aerospace Fasteners Inc
Priority date: 1985-03-29
Filing date: 1985-11-29
Publication date: 1992-01-29
Also published as: IL76868A0; JPS61226276A; BR8600298A; DE3585322D1; EP0195851A2; CN85108469A; EP0195851A3

Description

The invention relates to a tool for installing and removing fasteners of the type having axially spaced first and second tool gripping surfaces which are rotated relative to each other to install the fastener in or remove the fastener from a panel, said tool comprising:

a main tool housing;
a motor connected to said housing, said motor having an output shaft for rotation in either rotational direction along a central axis of said tool;
a generally tubular first wrenching portion connected to said housing, said first wrenching portion having a first inner wall having a plurality of first camming surfaces;
a generally tubular second wrenching portion spaced axially from said first wrenching portion and connected to said output shaft for rotation therewith, said second wrenching portion having a second inner wall having a plurality of second camming surfaces; and
means for actuating said motor to rotate said shaft and said second wrenching portion in either rotational direction.

A tool of the aforementioned kind is known from US-A-3 331 268.
Various types of wrenching tools are known in the art. Generally, such wrenching tools are either adjustable to grip the part being installed or otherwise turned, or of a fixed irregular inner configuration of the device which it is desired to grip. In the aircraft industry, when it is desired to secure two panels together, apertures are made in these panels and devices, known as wedging-type fasteners, are temporarily installed in aligning apertures in the panels at predetermined locations. Such installation is usually carried out quickly and, preferably, automatically. The fasteners are later removed after installation of more permanent fasteners.
It is desired that the installer carry a suitable tool to effect such installation. It is necessary, with known tools and fasteners, to carefully align the wrenching portion of the tool to the fastener body to effect both proper installation and withdrawal after installation. This is a particular problem where the fastener body is not cylindrical, e.g. of hexagonal shape, because then the hexagonal tool gripping suface of the fastener has to be properly aligned with the hexagonal wrenching portion of the tool. If, in contrast, a fastener having a cylindrical body, were used, conventional wrenching tools could not be used to grip the cylindrical fastener body.
The tool described in US-A-3 331 268, mentioned at the outset, is of conventional design and serves to install temporary fasteners having hexagonally-shaped tool gripping surfaces. This prior art tool typifies the disadvantages in the art, namely the need to precisely align the wrenching portion of the tool with the hexagonally configured tool gripping surface of the fastener. Clearly, in the use of manual and robotic installation techniques, it oftentimes would be difficult to precisely align the two hexagonally-shaped wrenching portions of this prior art tool with the two hexagonally-shaped tool gripping surfaces of the fastener. Rotational adjustment of the tool wrenching portion and/or the fastener tool gripping surface would be needed in many instances and increase the amount of installation time and operator fatigue.
In US-A-2,719,447, a wrench head in a ratchet wrench is disclosed having spring-biased rollers used to rotate a hexagonally-shaped nut.
This pior art device, therefore, also needs precise alignment of the tool and the fastener, as explained before.
In another prior art tool, as described in US-A-1,589,736, a workpiece of round cross-section is rotated between dies having teeth. Such tool is quite complex, and the teeth must dig into the piece to rotate it.
Similar complex devices are disclosed in US-A-2 613 565 and 2 613 942, and, further, in US-A-3 889 557. These prior art devices are relatively expensive and difficult to use.
Further, documents US-A-3 331 268, 3 263 320 and 3 162 072 all show tools used to install wedging-type fasteners. The bodies of all the fasteners are irregularly shaped and gripped by the wrench portion of the tool.
In US-A-2 408 335 a torque wrench is disclosed that may be used for gripping a cylindrical workpiece, e.g. a cylindrical stud, and for applying torque on the cylindrical workpiece in either a clockwise or a counter-clockwise direction for setting and releasing the workpiece, respectively.
This prior art torque wrench device includes a cage assembly having three cylindrical rollers, one of which being larger than the other two for cooperating with opposed cam surfaces of the roller housing. The roller assembly is maintained in a neutral or mid-position by a spring-biased ball partially entering into a radial bore. However, when the tool has been placed over a cylindrical workpiece, e.g. a stud, a manual adjustment handle must be moved to one side or the other, depending upon whether the stud is to be screwed more tightly into position or unscrewed and removed from its mounting. In other words, a special manual device has to be set appropriately into one of three distinct operational positions in order to determine whether torque is to be applied on the workpiece in a clockwise direction (screwing the stud), or in a counter-clockwise direction (unscrewing the stud) or whether no torque at all shall be transmitted.
In any of the two torque-transmitting positions of the handle, movement of the handle causes the larger working roller to move into engagement with either one of two cam surfaces, as the case may be. This accomplishes locking engagement of the stud between the three rollers. Thus, rotation of this prior art tool in one direction causes the rollers to grip the stud, while rotation of the tool in the opposite direction, with the handle position remaining unchanged, allows the rollers to spin freely with respect to the stud, like a typical conventional ratchet tool. Only after the manual adjustment handle is moved to the opposite position can the rollers tighten in the opposite direction.
Therefore, this prior art torque wrench device is not at all suited for being used in an installing tool for wedging-type fasteners as explained at the outset because this particular type of installing tools requires that torque may be applied on the tool gripping surfaces in either of the two directions by simply reversing the direction of rotation of the motor output shaft without doing further manual operations on wrenching devices.
It is, therefore, an object of the present invention to provide for a tool or a combination as mentioned at the outset, which allows to quickly install workpieces, in particular, wedging-type fastners without the need of precisely aligning the tool wrenching portions with the tool gripping surfaces of the workpiece or fastener, respectively, without necessitating manipulations on the tool for effecting torque transmission in clockwise or a counter-clockwise direction.
According to the tool for installing and removing fasteners, mentioned at the outset, this object is achieved by:

a first substantially cylindrical cage positioned concentrically with respect to said first inner wall;
a plurality of first rollers mounted and retained in said first cage, said first rollers being adapted to dilate sufficiently to fit over and engage said first tool gripping surface of the fastener when the fastener is inserted into said first wrenching portion of said tool;
first means for biasing said first rollers toward the central axis of said tool;
a second substantially cylindrical cage positioned concentrically with respect to said second inner wall;
a plurality of second rollers mounted and retained in said second cage, said second rollers being adapted to dilate sufficiently to fit over and engage said second tool gripping surface of the fastener when the fastener is inserted into the second wrenching portion of said tool;
second means for biasing said second rollers toward the central axis of said tool; wherein
application of torque in either rotational direction causing said second rollers of said second wrenching portion to move a limited distance into wedging engagement against said second camming suraces of said second inner wall of said second wrenching portion stopping movement of said second cage and causing said second rollers to grip the second tool gripping surface of the fastener and rotate the second tool gripping surface in the direction of rotation of said output shaft, while said first rollers of said first wrenching portion move a limited distance into wedging engagement against said first camming surfaces of said first inner wall of said first wrenching portion stopping movement of said first cage and causing said first rollers to grip the first tool gripping surface of the fastener and hold the first tool gripping surface against rotation to set the fastener.

The invention, therefore, achieves the underlying object entirely. The tool, according to the invention, is particularly adapted to install fasteners of the type having axially spaced cylindrical tool gripping surfaces which are rotated relative to each other to install the fastener in or remove the fastener from the workpiece. The tool according to the invention conveniently provides wrenching engagement with these cylindrical tool gripping surfaces without regard to the radial location of these surfaces and the tool wrenching portion. The advance which this tool provides in its field is particularly important where robotic installation of the fasteners is desired.
In summary, the installation and removal tool, as claimed in connection with the present invention, has the advantages that it can be placed over a fastener without the need for precisely aligning the tool over the fastener. The fastener may be installed by causing rotation of the wrenching portion in one direction. In a particular embodiment of the invention this causes rollers to move into wedging engagement with an inner wall stopping movement of a cage and causing the rollers to grip the tool gripping surface of the fastener and rotate it in the direction of the output shaft. Importantly, the tool installs and removes fasteners without any adjustment to the wrenching portion. All that is needed is to reverse the direction of rotation of the output shaft. In contrast, the torque wrench device as disclosed in US-A-2 408 335 would, at best, be able to engage cylindrical surfaces, it could, however, rotate them only in a single direction at a time. Therefore, if this prior art torque wrench device were used in an installing tool for wedging-type fasteners, operating the drive motor of the tool in a first rotational direction, would cause the roller cage to grip the cylindrical surface and rotate it in the same direction, but reversing the rotational direction of the drive motor would cause the rollers to spin freely with respect to the cylindrical surface. If the direction of torque transmission were to be reversed, it would be necessary to make a separate manual adjustment in order to enable the prior art torque wrench device gripping the fastener in the opposite direction.
In contrast to this, the tool or combination according to the present invention allows to reverse the direction of torque transmission by simply reversing the direction of output shaft rotation. Therefore, if the tool according to the present invention has engaged the workpiece, it can impart the rotational motion of the drive shaft in either rotational direction without disengaging from the workpiece and without making additional manipulations on the tool.
One embodiment of the invention is illustrated in the accompanying drawings in which

Fig. 1: is a vertical partly cross-sectional view of a portion of an installing tool having a wrench portion thereon in accordance with the teachings of the invention;
Fig. 2: is a vertical view of the complete installing tool of Fig. 1 shown installing a fastener;
Fig. 3: is a view taken along lines III-III of Fig. 2; and
Fig. 4: is a view taken along lines IV-IV of Fig. 1.

Referring now to Fig. 1 of the drawing, a portion of an installing tool 10 is shown having a wrench portion 11 adapted to be threaded, via threads 12, to mating threads 13 on the housing 14 of a conventional drill motor. 15 (see Fig. 2). A roller housing 16 is threaded, via threads 17, to threads 18 on the outside of a reduced diameter section 19 of wrench portion 11. Housing 16 includes an inner wall 20 which, as particularly contemplated in the present invention, is irregularly configured. For example, wall 20 may be polygonally-shaped, such as being twelve sided. A cage 21 is trapped within housing 16. Housing 16 (Fig. 1) may have a main inner wall portion 22 of one diameter and wall 20 may be of a reduced diameter receiving therein cage 21.
Cage 21 is retained in tool 10 by abutment at one end against the shoulder 23 forced at the intersection between wall portions 20, 22 and at the other end by abutment with the end wall 24 of the nut drive shaft housing 25 of wrench portion 11.
Cage 21 is a cylindrical member having a plurality of elongated equally spaced openings 26 thereon (Fig. 4). For example, six such openings may be provided. A plurality of drive rollers 27 are provided in each opening 26 of a width greater than the width of openings 26 and disposed between cage 21 and wall 20. In this manner, as seen in Fig. 4, the rollers 27 extend through openings 26 in cage 21 but cannot pass therethrough.
As seen in Fig. 3, each roller 27 includes a reduced diameter mid-section 28 separating enlarged diameter roller sections 29 and 30. The ends of each roller section 29, 30 terminate in reduced ends 31, 32, respectively. These ends 31, 32 are trapped between the end walls 33, 34 respectively, of cage 21 which abut against shoulder 23 and wall 24 as shown. Cage 21 is thus a cylindrical member having inwardly extending end flanges or walls 33, 34 (see also Fig. 4) and openings 26 therein.
As seen in Fig. 3, a conventional resilient spring, such as a garter spring 35, is disposed between each roller reduced section 28 and the wall 20. As also seen, particularly in Figs. 1 and 3, a conventional wedging-type fastener 36 is shown disposed internally of tool 10. Fastener 36 has a first main body 37, cylindrical in cross-sectional (see particularly Fig. 4), of a first diameter gripped by tool 10. As can be seen in Fig. 4, the rollers 27 extend out of openings 26 and abut against body 37.
Fastener 36 also includes a body portion 38, of a lesser diameter than body portion 37, and also cylindrical, and a forward body portion 39 which may also be cylindrical and of diameter generally related to the diameter of body portion 37 and a forward carrier portion 46.
As seen in Fig. 2, the tool 10 includes the reversible, controllable torque motor 15 secured to the forward end of housing 14. The motor 15 is operated by a trigger 40 as is well known in the art. A similar tool is described in U.S. Patent No. 3,263,320, the teachings of which are incorporated herein by reference.
Housing 14, and the drill motor output shaft 41 (Fig. 1), motor 15, and trigger 40 and handgrip 42 (Fig. 2) are all part of a conventional tool as is well known in the art. The shaft 41 includes a hex recess 43 for receiving therein the wrenching portion 11 of the tool. Fastener 36 also includes pins 44, 45 extending from carrier portion 46 of fastener 36 (Figs. 1 and 2). Pins 44, 45 are shown extending through aligned openings 47, 48 (Fig. 2) in panels 49, 50, respectively, all as is well known in the art. A spreader 51 is disposed between pins 44, 45 as is well known in the art. The enlarged heads 52, 53 extend on the blind side of panels 49, 50, as shown.
The wrenching portion 11 also includes a nut drive shaft 54 disposed internally of the nut drive shaft housing 25. A cupped thrust washer 55, L-shaped in cross-section, is disposed between the drill motor housing 14 and nut drive shaft 54, separated by a conventional thrust bearing 56. A retaining ring 57 mounted in a reduced end section 58 of shaft 54 holds shaft 54 in position with respect to washer 55. A hexagonally shaped spline drive shaft 59, having an annular ring 60 thereon, is mounted in hex opening 43 and thus conforms thereto and is driven by shaft 41 when motor 15 is activated. Ring 60 abuts against the end wall 61 of shaft 41 and is biased by a compression spring 62 encircling shaft 59 between ring 60 and the end wall 63 of reduced portion 58 of shaft 54.
Shaft 54 has an inner cavity 64 of an inner wall configuration similar to wall 20. A nut roller cage 65 is mounted in cavity 64 having an end wall 66 abutting against a retaining ring 67 mounted in the thin wall portion 68 of shaft 54. It is to be understood that cage 65 is generally similar to cage 21 of Figs. 1, 2, 3 and 4 and includes spaced openings similar to openings 26 and has rollers 27 mounted therein all as heretofore disclosed. These rollers 27, in cavity 64, as seen in Fig. 1, abut against a round or cylindrical shaft portion 68' of fastener 36. Finally, a spring 69, similar to spring 35, is provided between rollers 27, in cavity 64, and the inner wall thereof as shown.
To assist in the retention of fastener 36 within tool 10, a conventional ball lock is provided at the forward end of tool 10 in the form of trapped balls 70, retained therein by a body retainer ball spring 71. Balls 70 extend slightly out of openings 72 in the forward end of housing 16 but are of a lesser diameter so they are trapped therein. They retract against the bias of spring 71 when fastener 36 is inserted therein and, thus, retain fastener 36 in tool 10 until it is desired to remove the same as is well known in the art.
In operation, a fastener, such as fastener 36, which may have a cylindrical main body portion 37, is installed in the openings 47, 48 in panels 49, 50. The operator now comes along with tool 10 with wrenching portion or housing 16 installed thereon. The housing 16 is inserted over the portion of fastener 36 protruding on the access side of panel 49 (on the left thereof in Fig. 2). The diameter of the interior opening of cage 21 is related to the diameter of the cylindrical portion 37 so that portion 37 is insertible into cage 21 in a close fitting relationship. Portion 68' enters cage 65. The motor 15 is now actuated to rotate output shaft 41 in a clockwise direction.
Such rotation forces or wedges rollers 27 against the irregularly shaped inner surface of cavity 64 locking the cage 65 in cavity 66. The rollers 27 also wedge against the cylindrical surface of cylindrical portion 68' thereby holding the cage 65 to the cylindrical captive nut 68' of the fastener 36 and thus rotating the fastener 36 to install the same as is well known in the art when the tool 30 is actuated to rotate shaft 59 and thus rotate nut drive shaft 54 while cage 21 holds portion 37 in a non-rotating relationship. After installation, the operator merely counter-rotates the fastener 26 in the same manner.
It can be seen that, in this manner, fastener 36 and any other similar wedging-type fastener, can be quickly and easily installed in or removed from panels 49, 50. The unique cage assembly and configuration of housing 11 provides for any misalignment of the tool 30 to the fastener body 37. It is not necessary that the fastener be precisely aligned with respect to the wrenching portion of the tool. The wrench portion can be provided separately for installation in a particular tool or as a complete tool assembly. The device disclosed herein lends itself to automatic insertion and removal of wedging-type fasteners, particularly those having cylindrical body portions.

Claims

A tool for installing and removing fasteners (36) of the type having axially spaced first and second tool gripping surfaces (37, 68') which are rotated relative to each other to install the fastener (36) in or remove the fastener (36) from a panel (49, 50), said tool (10) comprising:
- a main tool housing (14);

- a motor (15) connected to said housing (14), said motor (15) having an output shaft (41) for rotation in either rotational direction along a central axis of said tool (10);

- a generally tubular first wrenching portion connected to said housing (14), said first wrenching portion having a first inner wall (20) having a plurality of first camming surfaces;

- a generally tubular second wrenching portion spaced axially from said first wrenching portion and connected to said output shaft (41) for rotation therewith, said second wrenching portion having a second inner wall (64) having a plurality of second camming surfaces; and

- means (40) for actuating said motor (15) to rotate said shaft (41) and said second wrenching portion in either rotational direction,
characterized by:
- a first substantially cylindrical cage (21) positioned concentrically with respect to said first inner wall (20);

- a plurality of first rollers (27) mounted and retained in said first cage (20), said first rollers (27) being adapted to dilate sufficiently to fit over and engage said first tool gripping surface (37) of the fastener (36) when the fastener (36) is inserted into said first wrenching portion of said tool;

- first means (35) for biasing said first rollers (27) toward the central axis of said tool (10);

- a second substantially cylindrical cage (65) positioned concentrically with respect to said second inner wall (64);

- a plurality of second rollers (27) mounted and retained in said second cage (65), said second rollers (27) being adapted to dilate sufficiently to fit over and engage said second tool gripping surface (68') of the fastener (36) when the fastener (36) is inserted into the second wrenching portion of said tool (10);

- second means (69) for biasing said second rollers (27) toward the central axis of said tool (10); wherein

- application of torque in either rotational direction causing said second rollers (27) of said second wrenching portion to move a limited distance into wedging engagement against said second camming suraces of said second inner wall (24) of said second wrenching portion stopping movement of said second cage (65) and causing said second rollers (27) to grip the second tool gripping surface (68') of the fastener (36) and rotate the second tool gripping surface (68') in the direction of rotation of said output shaft (41), while said first rollers (27) of said first wrenching portion move a limited distance into wedging engagement against said first camming surfaces of said first inner wall (20) of said first wrenching portion stopping movement of said first cage (21) and causing said first rollers (27) to grip the first tool gripping surface (37) of the fastener (36) and hold the first tool gripping surface (37) against rotation to set the fastener (36).
The tool of claim 1, characterized in that there are at least three rollers (27) mounted in the cage (21, 65).
The tool of claim 1, characterized in that there are twelve flat surfaces on each of the inner walls (20, 64) of the associated open ends of said drive shaft (41, 54, 59) and said nosepiece (16), and that there are six rollers (27) mounted in said cage (21, 65).
The tool of claims 1 through 3, characterized in that each of said rollers (27) comprises a substantially cylindrical roller element having two substantial cylindrical outer body sections (29, 30) of a first diameter separated by a central body section (28) of a smaller diameter than said first diameter.
The tool of claims 1 through 4, characterized in that said means for biasing said rollers (27) in a radially inward direction comprises a garter spring (35, 69) positioned around the central body section (28) of each of said rollers (27).