US3587271A

US3587271A - Manually operable tool for installing blind anchor nuts

Info

Publication number: US3587271A
Application number: US808492A
Authority: US
Inventors: Robert M Rigot
Original assignee: Aerpat AG
Current assignee: Aerpat AG
Priority date: 1969-03-19
Filing date: 1969-03-19
Publication date: 1971-06-28
Anticipated expiration: 1988-06-28
Also published as: FR2035064A1; FR2035064B1; DE2009428B2; DE2009428C3; GB1238154A; JPS5037919B1; DE2009428A1

Abstract

A MANUALLY OPERABLE TOOL FOR INSTALLING BLIND ANCHOR NUTS HAS A THREADED MANDREL WHICH CAN BE ROTATED BY A SHAFT HAVING AT ONE END A KEY ENGAGING A SOCKET ON THE MANDREL AND AT THE OTHER END A PROJECTING HANDLE. THE SHAFT IS BOTH ROTATABLE AND RECIPROCABLE, SO THAT THE KEY CAN BE DISENGAGED FROM THE MANDREL TO ALL ROTATION OF THE MANDREL IN SUCCESSIVE STEPS BY REPEATED ROTATION OF THE HANDLE THROUGH A SMALL ANGLE. THE MANDREL, THE KEY, AND AN ANVIL SURROUNDING THE MANDREL, MAY BE REMOVABLE AND INTERCHANGEABLE.

Description

United States Patent i 13,ss7,271

Robert M. Rigot Granada Hills, Calif.

Mar. 19, 1969 Aerpat A. 6.. Zug. Switzerland Inventor Appl. No. Filed Patented Assignee MANUALLY OPERABLE TOOL FOR INSTALLING BLIND ANCHOR NUTS 10 Claims, 11 Drawing Figs.

U.S. Cl 72/114, 81/55, 29/282 Int. Cl 821] 15/12, B2ld 39/04 Field of Search 81/55, 56,

53; 29/270, 282; 72/1 14, 391, (Inquired) [56] References Cited UNITED STATES PATENTS 2,562,419 7/1951 Ferris 72/391 3,462,988 8/1969 Tudoretal. 72/114 Primary Examiner-James L. Jones, Jr. An0rneyl(emon, Palmer and Estabrook ABSTRACT: A manually operable tool for installing blind anchor nuts has a threaded mandrel which can be rotated by a v shaft having at one end a key engaging a socket on the mandrel and at the other end a projecting handle. The shaft is both rotatable and reciprocable, so that the key can be disengaged from the mandrel to allow rotation of the mandrel in successive steps by repeated rotation of the handle through a small angle. The mandrel, the key, and an anvil surrounding the mandrel, may be removable and interchangeable.

mi nnnnm mum!!! llorney MANUALLY OPERABLE TOOL FOR INSTALLING BLIND ANCHOR NUTS The invention relates to a manually operable tool for installing blind anchor nuts. By f'blind anchor nut is meant a device comprising a tubular body portion and an internally threaded nut portion, the nut portion being capable of being pulled towards the tubular body portion to deform the body portion to tightly grip the walls of a suitable aperture in which the body portion is inserted, thereby to install the anchor nut securely in the aperture. The anchor nut is blind" in that its installation requires access to one side only of the aperture. One example of such a blind anchor nut is that widely sold under the Registered Trade Mark NUTSERT.

It is an object of the present invention to provide a manually operable tool for installing such blind anchor nuts which is simple in construction and economic in manufacture, and is also simple and foolproof in use and unlikely to require maintenance or servicing in use.

It is another object of the invention to provide such a tool which is readily adaptable to fit anchor nuts of different sizes.

It is a further object of the invention to provide such a tool in which considerable force can be applied to install the anchor nut, and which can be used to install nuts in relatively inaccessible positions.

Other objects of the invention will become apparent from the following description, by way of example only, of one way of putting the invention into practice. The description refers to the accompanying drawings, in which:

FIG. 1 is a side elevation, partially in section, of the example hand tool in a first operational configuration;

FIG. 2 is a similar view of the tool in a second operational configuration;

FIG. 3 is a section on the line III-III of FIG. 2;

FIG. 4 is a section on the line IV-IV of FIG. 2;

FIG. 5 is an end elevation of the tool, taken in the direction of the arrow V in FIG. 2;

FIG. 6 is an end elevation of the tool, taken in the direction of the arrow VI in FIG. 2; and

FIGS. 7 to 11 illustrate on an enlarged scale, successive stages in the placing of an anchor nut by the tool.

The manually operable tool of this example comprises a body member ll having a bore 12 extending throughout its length. At one end of the bore there is an annular anvil 13 for engaging the body part of an anchor nut. The anvil has a serrated outer end face 14 for frictionally engaging the body of the anchor nut, the serrations being in the form of radial V- section ribs and grooves. The annular anvil surrounds an aperture in the form of a bore 15 through it, which is aligned coaxially with the bore 12 in the body member. Formed integrally with the body member 11 is a grip in the form of a radially projecting handle 16, by means of which an operator can hold the body member and in particular prevent rotation thereof about the bore 12. The tool also has an interchangeable mandrel I7 positioned in the bore 16 in the anvil. The mandrel has an externally threaded portion 18 extending outwardly of the anvil, and at its other end a hexagonal socket 19 facing into the bore 12. The socket 19 is provided within an enlarged portion 21 at the inner end of the mandrel which prevents the mandrel from moving out through the bore 15 in the anvil. In the example, the mandrel I7 is provided by a hexagon cap socket screw, the enlarged portion 21 being the head of the screw. Washers may be provided between the screw head and the anvil 13.

The tool further comprises a shaft 22 which is reciprocable and rotatable within the bore 12 of the tool body. The shaft 22 is a sliding and rotating fit within an internal annular flange at the end of the bore 12 remote from the anvil 13. The shaft 22 is provided at its end nearer the anvil 13 with an interchangeable hexagon key 24 which will fit into and drivingly engage the socket 19 on the mandrel. The shaft 22 is also provided with a handle 25 outside the body member of the tool. The handle 25 projects transversely of the shaft 22, so that it can be used by the operator for both rotating and reciprocating the shaft 22 within the body member. The shaft is freely reciprocable between a first position (illustrated in FIG. I) in which the key 24 drivingly engages in the socket 19 on the mandrel, so that rotation of the shaft 22 by means of the handle 25 causes rotation of the mandrel l7, and a second position (illustrated in FIG. 2) in which the key 24 is disengaged from the socket 19 on the mandrel, so that the shaft 22 may be rotated without rotating the mandrel. When the shaft is in the second position, the screw mandrel 17 may move back through the anvil, but not sufficiently far to fall out ofthe bore 15 of the anvil.

In the tool of this example, the annular anvil I3 is interchangeable. The anvil is releasably retained in the body member by means of a retaining screw 26 engaged in a threaded hole 27 in the wall of the bore 12, the screw 26 being screwed into engagement with the anvil. The anvil is provided with a radial bore 28 into which the end of the screw 26 enters.

The interchangeable hexagon key 24 on the shaft 22 is received within a recess 29 in the end of the shaft. The shape of the socket, and of the part of the key 24 which is received within the socket, are of suitable complementary noncircular shape to ensure positive rotation of the key by the shaft. For example, the socket and the key body may both be hexagonal, or may be of cross-sectional shape of a circle with one or more flats in the side. The key 24 is releasably retained in the socket 29 by means of a screw 31 engaged in a threaded hole 32 in the side wall of the socket 29, and engaging with the part of the key 24 within the socket.

In the tool of this example, there is also provided releasable retaining means for releasably retaining the shaft 22 within the bore 12. This releasable holding means is provided by an annular tapered shoulder 33 inside the bore 12 of the tool body and facing towards that end of the bore which has the anvil 13. The shoulder 33 is provided by the inner end face of the flange 23. The shaft 22 is provided with a pair of detent members in the form of two

small steel balls

34, 35, carried within a transverse bore 36 in the shah. The

balls

34, 35 are each urged outwardly by means of a helical coil spring 37 working between them within the bore 36. The metal surrounding each end of the bore 36 is staked or paned over to prevent either ball emerging completely from the bore. When the shaft is in the first position (shown in FIG. I), the position of the bore 36 and

balls

34, 35 is well away from the annular shoulder 33 on the inner end of the flange 23. The spring 37 urges the

balls

34, 35 to project outwardly from the shaft 22, but they do not project sufficiently to contact the wall of the bore 12. However, when the shaft is moved back to the second position (shown in FIG. 2), the balls meet the tapered annular shoulder 33 on an inclined line of contact. The abutting of the

balls

34, 35 against the shoulder 33 restrains further movement of the shaft, thereby defining the second position of the shaft, and also acting as means to releasably retain the shaft within the bore. In order to withdraw the shaft 22 from the bore, it is necessary for the

balls

34, 35 to be retracted into the bore 36 against the urging of the spring 37, by the inclined face of the shoulder 33. The size and position of the

balls

34, 35 and the slope of the annular shoulder 33, and the strength of the spring 37, are arranged such that the operator can withdraw the shaft 22 from the bore by a sharp tug on the handle 25, whilst holding the body member of the tool by means of the grip handle 16. This allows access to the key 24 for removal and interchange thereof.

The operation of this tool will now be described, using as an example of a fastener the one illustrated in FIGS. 7 to 11. This particular fastener is one commercially available under the Registered Trade Mark "NUTSERT". The fastener comprises a tubular body portion 51, having at one end a small head in the form of an outwardly extending flange 52. At the other end the tubular body portion joins the narrower end of an internally threaded nut portion 53, which has a tapering exterior 54. The fastener is to be placed in a circular hole 55 in a metal sheet 56. The mandrel of the tool is chosen so that its threaded portion 18 mates with the internal threading 50 on the nut 53. In use, the fastener is first inserted into the hole 55 with the head 52 towards the operator, until the head 52 abuts the sheet 56. With the shaft 22 of the tool in its first position (in which the key 24 engages the mandrel socket t9), the operator offers the threaded end E8 of the mandrel through the body portion 51 of the fastener and into the threaded nut portion, rotating the handle 25 continuously in a clockwise direction by turning it with one finger, whilst holding the body of the tool in his other hand by means of the grip handle 16. In this manner the threaded portion 18 of the mandrel is screwed fully into the nut portion of the fastener, until the serrated face 14 of the anvil I3 is drawn tightly against the head 52 of the fastener (this position is illustrated in FIG. 9). The serrations on the face 14 of the anvil engage with the head end of the fastener to prevent rotation thereof with respect to the body of the tool. In order to draw the nut portion of the fastener into the body portion, the operator continues to rotate the mandrel in a clockwise direction. In order to apply the considerable torque required to the mandrel, the operator holds the grip handle 16 in one hand and the shaft handle 25 in the other, and repeatedly carries out the following steps in sequence:

1. with the shaft 22 in its first position (in which the key 24 engages the mandrel socket 19), forcefully turns the bandle 25 clockwise with respect to the handle 16 through a small angle, thus screwing the fastener nut portion 53 towards the anvil face 14;

2. pulls on the handle 25, thus moving the shaft 22 from its first position to its second position (in which the key 24 is disengaged from the mandrel socket l9);

3. returns the handle 25 through the aforesaid small angle in an anticlockwise direction to substantially its original angular position;

4. pushes on the handle 25 to return it to its first position in which the key 24 engages in the mandrel socket 19(rotating the shaft slightly, if necessary, so that the hexagonal key 24 engages in the hexagonal socket l9).

Thus if by repeated short amounts the nut portion 53 of the fastener is drawn into the body portion 51, shearing the junction between the two portions and eventually pulling the tapered nut portion completely into the body portion, expanding the latter and securely wedging the fastener in the hole (this position is illustrated in FIG. The operator then, with the shaft 22 in its first position with the key 24 engaging in the mandrel socket 19, rotates the shaft anticlockwise to unscrew the threaded mandrel from the nut portion of the fastener, leaving the placed fastener in the sheet (as illustrated in FIG. 1 l

It is found that an operator can exert considerable torque on one handle of the tool with respect to the other, but only over a restricted range of angle between the two handles, due to the variation in relative position of the operators hands and arms as he rotates the handles relative to each other. The hand tool of this example enables the blind anchor nuts to be installed by repeated application of such a force, whilst at.the same time the construction and operation of the tool is extremely simple. It is intended that this tool should be used in situations where power operated tools cannot be used, i.e. for repair work under field conditions, or as part of the repair tool kit of a motor vehicle.

Furthermore the tool allows easy and speedy interchange of the screw threaded mandrel, together with interchange of the key 24 and anvil 13, which is necessary since a different diameter mandrel will certainly require an anvil with a different diameter aperture and possibly a different size of driving key for the hexagonal socket. Thus the tool can readily be adapted to place blind anchor nuts with different sizes and/or internal thread. The tool may, of source, be used to install blind anchor nuts of types other than that described in the foregoing example.

Since the tool is operated by relative reciprocation of the two

handles

16 and 25 over a relatively small angle, it is possible to use the tool to install a blind anchor nut in situations which have relatively restricted access, for example near the corner point of three mutually perpendicular walls.

The invention may of course be put Into practlce otherwise an annular anvil at one end of the bore for engaging the body part of an anchor nut, the annular anvil surrounding an aperture aligned with the bore; 1

a grip by means of which an operator can hold the body member to prevent rotation thereof about the bore;

an interchangeable mandrel positioned in the aperture in the anvil, the said mandrel having an externally threaded portion extending outwardly of the anvil and a socket facing into the bore;

a shaft rotatable and reciprocable in the bore of the body member which shaft is provided at one end with key which will fit into the socket on the mandrel in driving engagement therewith, the shaft also being provided with a handle outside the body member of the tool by means of which the shaft can be both rotated and reciprocated with respect to the body member;

the shaft being reciprocable between a first position in which the key on the shaft engages in the socket on the mandrel thereby allowing rotation of the mandrel by means of the handle, and a second position in which the key disengages from the socket thereby allowing rotation of the handle without rotation of the mandrel.

2. A tool as claimed in claim 1, in which the said annular anvil is interchangeable.

3. A tool as claimed in claim 2, including releasable retaining means for releasably retaining the said anvil on the body member ofthe tool.

4. A tool as claimed in claim 3, in which the releasable retaining means comprises a threaded hole in the body member, and a retaining screw screwed into the hole and into engagement with the anvil.

5. A tool as claimed in claim 1, in which the said key at the said one end of the shaft is interchangeable.

6. A tool as claimed in claim 5, in which the said one end of the shaft has a noncircular recess in which the key fits, and is provided with releasable retaining means for releasably retaining the key in the recess.

7. A tool as claimed in claim 1, in which the said grip projects transversely from the body member of the tool.

8. A tool as claimed in claim 1, in which the said body member of the tool and the said grip are formed integrally with each other.

9. A tool as claimed in claim 1, including means for releasably retaining the said reciprocable shaft within the bore of the body member, said retaining means being releasable to permit withdrawal of the shaft from the bore to enable access to the key.

10. A tool as claimed in claim 9, in which the said releasable retaining means comprises an annular shoulder inside the bore of the body member of the tool facing towards the said one end of the bore, at least one detent member carried by the said reciprocable shaft, and spring means urging the or each said detent member transversely outwardly of the shaft so it engages the said annular shouldcr along an inclined line of contact, the arrangement of the or each detent member and the annular shoulder, and the strength of the spring means, being such that an operator can by a manual pull on the shaft with respect to the body member overcome the spring means and withdraw the shaft out of the bore.