US3728882A

US3728882A - Tool for placing threaded inserts

Info

Publication number: US3728882A
Application number: US00176199A
Authority: US
Inventors: R Rigot; D Goettlings
Original assignee: Aerpat AG
Current assignee: Aerpat AG
Priority date: 1971-08-30
Filing date: 1971-08-30
Publication date: 1973-04-24
Anticipated expiration: 1990-04-24
Also published as: GB1399939A; CA978727A

Abstract

A tool for placing threaded inserts, of the type comprising a threaded first part which is pulled towards a second part to place the insert, has a generally tubular body integral with a radially extending body handle. A rotatable sleeve within the rear part of the body carries a reciprocable and rotatable shaft, to the forward end of which is connected a screw which protrudes through an annular anvil. The rear of the shaft carries a rotatable cam which is integral with a radially extending cam handle and bears against a roller mounted in the sleeve. The cam handle can be used both to rotate the shaft and screw, and to rotate the cam so as to retract the screw with respect to the body of the tool.

Description

United States Patent Rigot et al.

[451 Apr. 24, 1973' INSERTS TOOL FOR PLACING THREADED Inventors: Robert M. Rigot, Granada Hills;

[52] US. Cl ..72/l14, 29/243.52 [51] Int. Cl. ..B21j 15/04 [58] Field of Search ..29/243.52. 267, 507; 72/114, 391, 452

[56] References Cited UNITED STATES PATENTS 2,641,378 6/1953 Wilt ..72/391 2,771,207 11/1956 Ott ..29/243.52 3,462,988 8/1969 Tudor ..72/1 14 Aerpat A.G., Zug, Switzerland Aug. 30, 1971 Appl. No.: 176,199

2,369,910 2/1945 Morgan ..72/1 14 Primary Examiner-Robert C. Riordon Assistant Examiner-J. C. Peters AnorneyKemon, Palmer & Estabrook [5 7 ABSTRACT A tool for placing threaded inserts, of the type comprising a threaded first part which is pulled towards a second part to place the insert, has a generally tubular body integral with a radially extending body handle. A rotatable sleeve within the rear part of the body carries a reciprocable and rotatable shaft, to the forward end of which is connected a screw which protrudes through an annular anvil. The rear of the shaft carries a rotatable cam which is integral with a radially extending cam handle and bears against a roller mounted in the sleeve. The cam handle can be used both to rotate the shaft and screw, and to rotate the cam so as to retract the screw with respect to the body of the tool.

PATENTEU R 2 E75 mmml TOOL FOR PLACING THREADED INSERTS This invention relates to a tool for placing threaded inserts. More specifically, it provides a manually operable tool for placing threaded inserts of the type comprising a threaded first part which is pulled towards a second part to place the insert.

It is an object of the invention to provide such a tool which is convenient and reliable in use, and can readily be adapted to place inserts of different sizes and thread forms. It is a further object of the invention to provide such a tool which can place an insert in a workpiece where there is restricted access, e.g. close to a projecting obstruction. Other objects of the invention will become apparent from the following description of one example of a tool embodying the invention.

In the accompanying drawings:

FIG. 1 is an exploded perspective view of the tool;

FIG. 2 is a side elevation of the tool ready to place an insert in a workpiece, the working parts of the tool being shown partly in section;

FIG. 3 is a side elevation, to an enlarged scale and partly in section, of certain of the working parts of the tool;

FIG. 4 is a plan, partly in section, taken in the direction of the arrow IV in FIG. 3;

FIG. 5, 6 and 7 correspond to the upper part of FIG. 2 and show successive configurations of the working part of the tool in placing an insert.

The tool of this example comprises a body 11 which is generally cylindrical about the axis B-B of a bore 12 which extends throughout the length of the body. The bore comprises a forward section 13 of small diameter, a rearward section 14 of large diameter, and a middle section 15 of intermediate diameter. The junction between the rearward section 14 and the middle section 15 provides an annular shoulder 16 facing towards the rear of the body. Housed within the rearward section 14 of the bore is a generally cylindrical sleeve 17 which is freely rotatable about the bore axis. The sleeve 17 is releasably. retained within the bore by means of one end 18 of a spring clip 19 which projects through a hole 21 in the wall of the body 1 l and engages in an annular groove 22 extending around the outside of the sleeve 17 about mid-way between its ends. The sleeve 17 is fixed against movement axially of the bore in the direction towards the forward end of the body beyond a predetermined position (shown in FIG. 2) by its forward end abutting against a hardened steel washer 23 which in turn seats against the annular shoulder 16.

A shaft 24 lies within the sleeve 17 and has its forward end extending into the middle portion 15 of the bore and its rearward end projecting beyond the rear end of the body. Near its forward end the shaft 24 is provided with a transverse aperture 25 of square sec- 1 tion. This is bounded at the forward end of the shaft 24 by a front wall 26 which has a U-shaped slot 27. The straight edges of this slot are parallel to the walls of the square-section transverse aperture 25. The inner curved end of the slot is semi-circular about the bore axis B-B, and the outer-end opens to the periphery of the shaft. A threaded member or mandrel is provided by a steel screw 28 having secured to it adjacent its head 29 a square nut 31. Also secured to the screw, adjacent the nut 31, is a washer 32 of appropriate external diameter to fit inside the curved inner end of the U- section aperture 25, so that the screw 28 also moves axially with the shaft 24.

The forward end of the tool body is provided with an interchangeable anvil 33. This has a cylindrical body 24 which fits within the forward portion 13 of the bore, and at its forward end a flange having a flat front face 35. The anvil is releasably retained on the tool body by means of a spring ball detent 36 which engages within an annular groove 37 on the cylindrical part 34 of the anvil. The screw 28 extends through the central bore of the anvil and projects forwardly of its front face 35.

The rearward portion of the shaft 17 is bifurcated, comprising two opposed

side wall portions

41, 42 separated by a cut-out portion 43 which extends along approximately the rear two-thirds of the length of the shaft. The two

side walls

41, 42 are each formed with a slot 44 extending parallel to the axial direction of the shaft and opposed to other slot. A first pin 45 extends diametrically across the sleeve 17, passing through the two slots 44, and carries at its centre a bearing roller 46 which is accommodated within the cut-out portion 43. Rearwardly of the two slots 44 a second pin 47 extends between the two

side wall portions

41, 42 along an axis C-C which is perpendicular to the bore axis B B and which lies in the diametral plane joining the centre lines of the two slots 44. This pin 47 carries a cam 48 which enters the rearward end of the cut-out portion 43 and bears against the bearing roller 46. Contact of the pin 45 with the side walls of the slots 44 causes the sleeve 17 to rotate with the shaft 24 in which the cam pin 47 is also mounted. Thus the roller pin 45 is kept parallel with the cam pin 47. Within the forward part of each slot 44 is provided a helical compressionspring 49, the forward end of each spring acting against the forward end of the respective slot 44 and the rearward end of the spring acting against the bearing roller pin 45 where it passes through the slot. The effect of the springs 49 is to urge the bearing roller 46 into contact with cam 48, and to urge the shaft 24 forwardly with respect to the sleeve 17.

Formed integrally with the tool body 1 1 is a first radially projecting handle 51, and formed integrally with the cam 48 is a second radially projecting handle 52. The handle 51 projects at right angles to the body bore axis B-B. To it is secured the other end of the spring clip 19. The relationship between the cam handle 52 and the cam 48 is such that, when the cam handle 52 is in a position parallel to the body handle 51 as illustrated in FIG. 2, the lowest point on the cam 48 is in contact with the roller 46. The height of the cam increases progressively over a sector of degrees from this point, so that if the cam handle 52 is progressively moved away from the body handle 51, the cam 48 rotates about its pin 47 to progressively retract the shaft 24 with respect to the sleeve 17. Furthermore, the cam handle 52 may be used to rotate the shaft 24 (together with the screw 28 and the sleeve 17) about their common axis B-B, no matter what the angular position of the cam handle 52 about the cam axis C-C, without altering the angular position of the cam 48 about its own axis. In particular, when the cam handle 52 is in a position with its own longitudinal axis aligned with axis B-B of the screw 28 and shaft 24 (as shown in FIG. 6), with an intermediate portion of the cam in contact with the roller, rotation of the screw 28 and shaft 24 is achieved by rotation of the cam handle 52 about its own longitudinal axis.

An insert to be placed by the tool is shown (in its original or unplaced condition) in FIG. 2. The insert comprises a nut portion 61 which is externally tapered, a cylindrical body portion 62 joining the nut portion at the narrow end of the taper and of slightly larger diameter, and an outwardly turned flange or head 63 at the end of the body 62 remote from the nut portion 61. Such inserts are well known in the art of mechanical assembly, and are commercially available under the trademark NUTSERT. In this example, the insert is to be placed in a suitably sized hole in a metal plate part of which is shown at 64.

To use the tool, the appropriate size and type of screw 28 to engage the nut portion of the insert is first selected and installed in the tool. To do this, the spring 19 is pulled away from the body 1 I so that the free end 21 of the spring disengages from the annular groove 22 in the sleeve 17. The assembly of the sleeve 17 and shaft 24 is then withdrawn from the body of the tool by pulling rearwardly on the cam handle 52. The appropriate screw 28 is then coupled to the front end of the shaft 24 by sliding its head end sideways into the square section aperture 25, as indicated by the arrow S in FIG. 1, until it occupies the position shown in FIGS. 2, 3 and 4. An anvil 33 with an appropriate diameter internal bore is also selected and inserted in the forward end of the body where it is retained by the spring detent 36 already described.

With the tool arranged so that the cam 48 is in the position illustrated in FIG. 2 in which the screw28 is in its most forward position so that the maximum length thereof protrudes from the anvil 28, the insert is then screwed on to the projecting front end of the screw 28, with its head 63 towards the anvil face 35, until the insert head contacts the anvil face. With the insert thus screwed up tight against the anvil face 35, the tool is so positioned by the. operator that the insert is inserted through the hole in the plate 64 and the underside of the insert head 63 is pressed against the plate. The operator then holds the tool body stationary by means of the body handle 51, and progressively swings the cam handle 52 about its pivot pin 47 away from the body handle 51. It will be apparent that as the cam 48 rotates whilst bearing against the roller 46, the progressively increasing height of the cam in contact with the roller 46 retracts the shaft 24 and consequently retracts the screw 28 with respect to the anvil face 35. This pulls the nut portion 61 of the insert towards the body portion 62, causing the junction between the nut portion and the body portion to sheer and eventually pulling the externally tapered nut portion right into the body portion which is thereby expanded radially to firmly grip the plate 64. Successive stages in this action are illustrated at the left hand sides respectively of FIGS. 2, 5, 6 and 7.

It will be apparent that the necessary rotation of the cam through approximately 180 about its own axis may be achieved simply by the operator moving the cam handle 52 through 180, so that the cam handle 52 then extends transversely on the opposite side of the tool body from the body handle 51. However, such a movement may not be convenient, as the operator may find that he is unable to move his hands through the required angle relative to each other whilst still maintaining the necessary force between the handles. Further, if the insert is being placed in a position in the sheet 64 near an obstruction which extends outwardly from the sheet, there may not be room for the operator to complete the 180 rotation of the cam handle 52 about its own axis. The tool of the present example is advantageous in that it enables the operator to overcome such difficulties, in the following manner. From the initial position illustrated in FIG. 2, the operator moves the cam handle 52 through only about its pivot pin 47, to the position where the length of the cam handle 52 is aligned with the axis B-B of the tool body bore. This is the position illustrated in FIG. 5, the arrow B indicating the manner in which the handle has been moved. The operator then rotates the cam handle 52 through about its own longitudinal axis, to the position shown in FIG. 6 in which the arrow F indicates the movement which has just taken place. It should be noted that since this rotational movement also causes the screw 28 to rotate, it may not be possible to carry out this rotation in a clockwise direction, since the rotational force which can be applied to the cam handle 52 for this movement would be insufficient to pull the externally tapered nut portion 61 of the insert any further into the insert body 62. Even if this were possible, it would cause excessive wear on the threads of the screw 28 engaged in the insert nut portion. Therefore it is desirable and/or necessary that the rotation of the cam handle 52 about its own axis should be in the anti-v clockwise direction (as indicated by the arrow F in FIG. 6). This of course causes a slackening of the engagement of the screw 28 in the insert by l turn.

Comparing the two positions illustrated respectively in FIGS. 5 and 6, it will be noted that whereas in FIG. 5 the portion of the cam of lesser height which has been already traversed across the roller 46 is facing towards the tool handle 51 and the portion of the cam face of greater height is facing away from the tool body handle 51, after the 180 rotation of the cam handle 51 about its own axis the portion of' greater height of the cam face is now facing towards the tool body handle 51. The operator now merely grasps both

handles

51 and 52 firmly again and moves the cam handle 52 about its axis pin 47 towards the body handle 51 until the two handles are again parallel. The position is then as illustrated in FIG. 7, in which the arrow G indicates the movement just made. It will be seen that this movement completes the traverse of the cam face past the roller 46, thus completing the retraction of the shaft 24 and screw 28, and completing the pulling of the nut portion 61 of the insert into the body portion 62. The insert is thus fully placed in the sheet 64. The tool is then disengaged from the fullyplaced fastener by disengaging the screw 28, by rotating it in an anti-clockwise direction by means of the cam handle 52.

The tool described in this example has numerous advantages in practise. It is relatively simple to manufacture, it is of robust construction and easy maintenance. The screw 28 and anvil 33 can readily be removed and replaced by other parts appropriate to place inserts of different thread form and size. To this end the body handle 51 may be provided with one or more threaded holes 65 by which may be carried a spare screw 28 carrying its appropriate anvil. It can be used to place inserts in awkward corners, whilst the

handles

51 and 52 enable the operator to hold the tool steady and to apply the necessary leverage wihout undue effort or discomfort. The roller 46 and the hardened steel washer 23 provide for low friction and long life of parts in the rotation of the sleeve 17 and cam 48 respectively. The springs 49 keep the cam 48 in contact with the roller 46, and return the sleeve 17 and screw 28 to their forward position, ready to receive another insert, as the cam 48 is rotated about its axis to return it to its initial position.

The scope of the invention is defined by the appended claims, and may be put into practice in other ways than disclosed in the foregoing example.

We claim:

1. A manually operable tool for placing threaded inserts of the type comprising a threaded first part which is pulled towards a second part to place the insert, which too] comprises:

a body, the body having a bore extending therethrough along a bore-axis;

an anvil at one end of the body for engaging the second part of an insert to be placed by the tool; a shaft extending longitudinally inside the bore, the said shaft being rotatable and reciprocable with respect to the body; one end of the said shaft adjacent the aforesaid one end of the body being provided with a threaded member for engagement with the first part of an insert to be palced by the tool, the said threaded member being operatively connected to the said shaft for rotation and reciprocation therewith; an auxiliary member mounted on the body for rotation with respect thereto about the bore-axis but fixed against movement with respect thereto beyond a predetermined position in the direction along the bore axis towards the said one end;

bearing means mounted on the auxiliary member;

cam means rotatable about a cam-axis fixed with respect to the shaft at a position therealong remote from the aforesaid one end thereof, the said cam axis extending perpendicular to the bore axis;

the said cam means bearing against the said bearing means;

and a handle operatively connected to the said cam means, whereby both the shaft may be rotated about the bore axis to effect screwing engagement or disengagement of the threaded member, and whereby also the said cam means may be rotated about its axis to cause relative axial movement between the shaft and the body, and consequent relative axial movement between the said threaded member and the said anvil, to place an insert as aforesaid.

2. A tool as claimed in claim 1, in which the bearing means comprises a roller mounted on the said auxiliary member for rotation about a roller-axis perpendicular to the bore axis, which roller is operatively connected to the cam means to maintain the said roller-axis parallel to the said cam-axis.

3. A tool as claimed in claim 2, in which the operative connection between the said roller and the said cam means comprises part of the said shaft.

4. A tool as claimed in claim 2, in which the said shaft has a cut-out portion lying intermediate two opposed side-wall portions, the said roller being accommodated within the said cut-out portion of the said shaft.

5. A tool as claimed in claim 4, in which each of the said two side-wall portions is provided with a slot, the two slots being opposed to each other and extending longitudinally of the shaft parallel to the said bore axis; the tool further comprising a first pin defining the said roller-axis and extending transversely of the said shaft through the said cut-out portion and the said slots, the ends of the first pin being mounted on the aforesaid auxiliary member, the said roller being mounted on the portion of the said first pin within the said cut-out portion.

6. A tool as claimed in claim 5, in which the aforesaid cam-axis is defined by a second pin mounted transversely of the shaft between the two said side-wall portions in a plane aligned with the said slots, the said cam means being mounted on the portion of the said second pin within the said cut-out portion.

7. A tool as claimed in claim 1, in which the said auxiliary member comprises a sleeve around the said shaft and at least partially received within the said bore.

8. A tool as claimed in claim 5, in which the said auxiliary member comprises a sleeve surrounding the part of the said shaft in the region of the said slots, the ends of the aforesaid first pin being received in the said sleeve.

7 9. A tool as claimed in claim 8, in which the said sleeve is releasably mounted on the tool body.

10. A tool as claimed in claim 7, in which at least part of the sleeve is received within the said bore of the tool body at the end thereof remote from the said one end of the body, and retractable spring detent means engages the sleeve inside the said bore.

11. A tool as claimed in claim 1, including spring means for resiliently urging the said cam means into engagement with said bearing means.

12. A tool as claimed in claim 5, including a compression spring housed within each of the said slots, one end of each said compression spring acting against that end of the respective slot which is towards the aforesaid one end of the shaft, and the other end of each said compression spring acting against the said first pin, the said springs being effective to urge the said roller and the said cam means into contact with each other.

13. A tool as claimed in claim 1, in which the said threaded member is releasably connected as aforesaid to the said shaft.

14. A tool as claimed in claim 1, in which the said anvil comprises a separate member which is releasably attached to the body of the tool.

i I 1F

Claims

1. A manually operable tool for placing threaded inserts of the type comprising a threaded first part which is pulled towards a second part to place the insert, which tool comprises: a body, the body having a bore extending therethrough along a bore-axis; an anvil at one end of the body for engaging the second part of an insert to be placed by the tool; a shaft extending longitudinally inside the bore, the said shaft being rotatable and reciprocable with respect to the body; one end of the said shaft adjacent the aforesaid one end of the body being provided with a threaded member for engagement with the first part of an insert to be placed by the tool, the said threaded member being operatively connected to the said shaft for rotation and reciprocation therewith; an auxiliary member mounted on the body for rotation with respect thereto about the bore-axis but fixed against movement with respect thereto beyond a predetermined position in the direction along the bore axis towards the said one end; bearing means mounted on the auxiliary member; cam means rotatable about a cam-axis fixed with respect to the shaft at a position therealong remote from the aforesaid one end thereof, the said cam axis extending perpendicular to the bore axis; the said cam means bearing against the said bearing means; and a handle operatively connected to the said cam means, whereby both the shaft may be rotated about the bore axis to effect screwing engagement or disengagement of the threaded member, and whereby also the said cam means may be rotated about its axis to cause relative axial movement between the shaft and the body, and consequent relative axial movement between the said threaded member and the said anvil, to place an insert as aforesaid.

9. A tool as claimed in claim 8, in which the said sleeve is releasably mounted on the tool body.