WO2007008372A1

WO2007008372A1 - Tolerance compensating connector

Info

Publication number: WO2007008372A1
Application number: PCT/US2006/024533
Authority: WO
Inventors: Ralph Stewart Emery; Roger Derrick Stone
Original assignee: The Gates Corporation
Priority date: 2005-07-11
Filing date: 2006-06-23
Publication date: 2007-01-18
Also published as: TWI299381B; EP1907711A1; BRPI0612715A2; CN101243260A; KR20080025754A; TW200714811A; JP2009500583A; JP4926170B2

Abstract

A tolerance compensating connector (100) comprising a first member (10) having a threaded portion (12), a second member (20) comprising a bore (22) and an outer surface (21), the outer surface having a helical thread engagable with a receiver (40), the first member engaged with the bore, a third member (30) engaged with the first member and the second member, the third member transmitting a torque from the first member to the second member such that a first torque transmitted to the second member as the first member is turned in a first direction is sufficient to turn the second member in the receiver, the third member having a slipping engagement with the first member when the first torque is exceeded, and upon the first member being turned in a direction opposite the first direction the third member transmits a second torque to the second member sufficient to turn the second member in the receiver in a direction opposite the first direction.

Description

Title Tolerance Compensating Connector

Field of the Invention

The invention relates to a tolerance compensating connector, and more particularly to a tolerance compensating connector having a member for transmitting a torque from a fastener to a compensating sleeve which torque depends upon the direction of rotation of a fastener.

Background of the Invention

Assembly of equipment components can be adversely affected by tolerances, that is, dimensional differences between components creating gaps at fastening points to ease assembly. They can be eliminated, but this can make assembly more difficult. Tolerances can also "stack" or

"accumulate" when more than two components are joined at a particular location, creating a more significant dimensional deviation or gap.

Tolerances may be very small, fractions of a millimeter, or very large, several millimeters, depending upon the circumstances. Larger tolerances generally reduce manufacturing costs and make assembly more easy.

Attempts have been made in the prior art to eliminate tolerances or to compensate for them in an assembled device. These generally comprise shims or screw type devices that fill the gap between the mating surfaces of the components to be joined. The shims or screw type devices are generally a separate component from the fasteners .

Representative of the art is US publication number 2003/0077142 Al to Stone which discloses a tolerance compensating mounting device comprising a bushing having an internal and external thread. The bushing is threaded into a part to be mounted to a surface. A bolt is then threaded into a bushing bore using the internal threads. The internal threads cause an interference fit between the bolt shank and the threads, temporarily preventing further insertion of the bolt. The bolt is then turned, thereby turning the bushing and causing the bushing to unscrew from the part toward the mounting surface until the bushing bears upon the mounting surface, thereby completely compensating for a tolerance gap. As the bolt is turned further, the sacrificial internal threads are stripped to allow the bolt to be fully torqued into the mounting surface hole, thereby simultaneously connecting the components while compensating for a tolerance gap.

What is needed is a reusable tolerance compensating connector having a member for transmitting a torque from a fastener to a compensating sleeve which torque depends upon the direction of rotation of the fastener. The present invention meets this need.

Summary of the Invention

The primary aspect of the invention is to provide a reusable tolerance compensating connector having a member for transmitting a torque from a fastener to a compensating sleeve which torque depends upon the direction of rotation of the fastener.

Other aspects of the invention will be pointed out or made obvious by the following description of the invention and the accompanying drawings.

The invention comprises a tolerance compensating connector comprising a first member having a threaded portion, a second member comprising a bore and an outer surface, the outer surface having a helical thread engagable with a receiver, the first member engaged with the bore, a third member engaged with the first member and the second member, the third member transmitting a torque from the first member to the second member such that a first torque transmitted to the second member as the first member is turned in a first direction is sufficient to turn the second member in the receiver, the third member having a slipping engagement with the first member when the first torque is exceeded, and upon the first member being turned in a direction opposite the first direction the third member transmits a second torque to the second member sufficient to turn the second member in the receiver in a direction opposite the first direction.

Brief Description of the Drawings

The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention, and together with a description, serve to explain the principles of the invention.

Figure 1 is a side cross-sectional view of tolerance compensating connector.

Figure 2 is a cross-sectional view of the sleeve. Figure 3 is a perspective view of the sleeve.

Figure 4 is a cross-sectional side view of the coil member in Fig. 5.

Figure 5 is a plan view of the coil member. Figure 6 is a cross-sectional view of an alternate coil member in Figure 7.

Figure 7 is a plan view of an alternate coil member. Figure 8 is a cross-sectional view of an alternate sleeve . Figure 9 is a perspective view of an alternate sleeve .

Detailed Description of the Preferred Embodiment The invention comprises a tolerance compensating connector. Figure 1 is a side cross-sectional view of tolerance compensating connector. Connector 100 comprises a first member, namely, a fastener 10. Fastener 10 comprises a threaded portion 12, head 13 and flange 14. The embodiment shown in Figure 1 shows threaded portion 12 extending along the entire length of fastener 10.

Fastener 10 may comprise an SAE or metric thread on portion 12. Threaded portion 12 may comprise either left or right handed threads. Threaded portion 12 may comprise either coarse or fine threads of any known style and type. Fastener 10 may have a hex head, Torx head or any other suitable driver head known in the art . Thread portion 12 has a diameter D2. Second member or sleeve 20 comprises an outer threaded portion 21 and a bore 22. Outer threaded portion 21 comprises a helical thread for engaging a receiver portion 40. Outer threaded portion 21 may comprise an SAE or metric threads. Outer threaded portion 21 may comprise either left or right hand threads. Outer threaded portion 21 may comprise either coarse or fine threads of any known style.

Outer threaded portion 21 engages threaded portion 41 of receiver portion 40. Receiver portion 40 may comprise any component to be mounted to another component 50, for example, a water pump mounted to an engine block 50. Other components besides a water pump can include a starter motor, alternator, air conditioner compressor, fuel pump, power steering pump and so on. Engine block 50 comprises a threaded receiver portion 51, namely a threaded hole. Receiver portion 51 comprises threads 52 which cooperatively engage threaded portion 12 of fastener 10. Surface 24 bears upon a surface of the portion to which component 40 is attached, in this case, an engine block 50.

Third member 30 is engaged between the first member and the second member. Third member comprises a coil or coils 32 of wire or other resilient material that wraps about and thereby grips or clasps fastener 10. An end 31 of third member 30 is engaged with the second member 20 such that the third member cannot rotate with respect to the second member, but the third member may rotate with respect to the first member 10 in a predetermined direction Rl.

In use, first member 10 is inserted into the bore 22 of second member 20 while being simultaneously turned into third member 30. The assembly of the first member, second member and third member comprises the inventive tolerance compensating connector.

Connector 100 is then threaded into the receiver portion 40 by engagement between threaded portion 21 and threaded portion 41. Sleeve 20 is turned by applying a torque to fastener 10 until fastener 10 comes into contact with receiver portion 51, or until surface 24 comes into contact with component 50. In most cases surface 24 will contact component 50 before fastener 10 contact receiver portion 51. Once surface 24 is in contact with component 50 and fastener 10 is engaged with portion 51, fastener 10 is then fully threaded into receiver portion 51 until flange 14 engages surface 42 and torqued to a final value.

Third member 30 transmits a first torque from the fastener 10 to sleeve 20. The coil direction of third member 30 is such that it does not tightly grip fastener 10 as fastener 10 is threaded into receiving portion 51 and as sleeve 20 is turned into threaded portion 41. However, the grip is sufficient to cause sleeve 20 to turn in threaded portion 41. Third member 30 then slips on fastener 10 once the first torque is exceeded, that is, when sleeve 20 stops turning after surface 24 comes into contact with component 50. Once sleeve 20 stops turning fastener 10 is then fully screwed into the receiving portion 51 due in part to the slipping engagement between third member 30 and fastener 10.

During insertion of fastener 10, the engagement between third member 30 and fastener 10 must be sufficient to not only ensure contact between surface 24 and component 50, but sufficient so that sleeve 24 is torqued enough to ensure proper engagement of surface 24, namely, by overcoming parasitic friction between the surfaces so that substantially all of surface 24 is in contact with component 50. This ensures the load bearing capacity of sleeve 20 is fully developed thereby ensuring proper rigidity of the assembled components.

Sleeve 20 spans a gap "T" between components being connected. The size of gap T which can be spanned is only limited by the length of sleeve 20. Sleeve 20 only need have sufficient threads engaged with portion 40 to fully develop the theoretical shear strength required by the application. Once fastener 10 is fully torqued, sleeve 20 is held in place by a compressive load. Hence, the number of threads 21 which must be engaged with receiver portion 41 is a function of maximum preload in the fastener and thereby the shear load imposed upon the threads 21.

To withdraw the connector, the fastener 10 is turned in the direction opposite that used to engage it. As fastener 10 is turned the coil direction of third member 30 causes third member 30 to tightly grip fastener 10. Third member 30 grips the fastener tightly enough so that a sufficient second torque is transmitted from the fastener to the sleeve by the third member to cause sleeve 20 to be withdrawn from engagement with component 50 and from receiver portion 41. Unlike in the first direction, the third member does not slip on the fastener when the second torque is being transmitted to the sleeve. Put another way, the torque applied to the sleeve by the third member is dependent upon the direction of rotation of the fastener.

The insertion, or first, torque is generally less than the second or withdrawal torque, but this is not always the case. In some instances sleeve 20 will be locked in place once sleeve 20 is installed.

Connector 100 can be fully withdrawn fully intact from the components which it is used to attach together. Since the manner of operation of the connector is not sacrificial or damaging to any of its parts, the connector may be reused.

Figure 2 is a cross-sectional view of the sleeve. Sleeve 20 comprises outer threaded portion 21. Portion 21 may be threaded along its entire axial length as shown, or along a portion comprising less than its entire axial length. Bore 22 receives fastener 10. Receiving portion 23 may comprise a hole or other means for engaging end 31 of third member 30, see Fig. 5. Portion 21 has the same thread hand as the threaded portion 12 of fastener 10. This is to cause sleeve 20 to move in the same engagement direction as the fastener during engagement and disengagement .

Bore 22 has an inside diameter Dl that exceeds the outside diameter D2 of threaded portion 12, creating a loose engagement between the fastener 10 and sleeve bore 22. This also creates sufficient clearance between third member 30 and sleeve 20. Bore D4 provides clearance for third member 30. Figure 3 is a perspective view of the sleeve. Hole 23 is shown disposed at an end of sleeve 20 in a location that keeps end 31 from contacting threaded portion 41 during engagement. Hole 23 may be disposed at any location on sleeve 20 so long as end 31 does not interfere with threaded portion 41.

Figure 4 is a cross-sectional side view of the coil member in Fig. 5. End 31 extends radially and engages hole 23 in sleeve 20. Coils 32 wrap about fastener 10 in a predetermined direction. The direction of wrap determines whether third member 30 will lightly or tightly grip fastener 10 for a given rotational direction. An inside diameter D3 , see Fig. 5, is selected to cause the coils to grip threaded portion 12 of fastener 10. The coil comprises spring steel or its equivalent so that the coil exerts a spring force in response to the fastener "opening" the coils to a somewhat greater diameter than D3. In this way the coils "grip" fastener 10 in a manner similar to the operation of a band brake . Third member 30 further comprises a larger coil 320 having an inside diameter D5. D5 is greater than diameter D3 giving member 30 a somewhat tapered appearance. Diameter D5 facilitates engagement of the third member 30 with sleeve recess 220 as well as with 23.

The coils grip the fastener lightly when the fastener is turned in a first direction, for example during insertion of the fastener. The coils grip the fastener tightly when turned in the opposite direction, for example during withdrawal of the fastener. There need only be a number of coils 32 sufficient to develop the torque necessary to cause the sleeve to "back-out" of receiver portion 40 when fastener 10 is unscrewed from engagement with receiver portion 51. The coils need to also grip the fastener tightly enough to cause sleeve 20 to be threaded into threaded portion 41 as fastener 10 is turned.

Figure 5 is a plan view of the coil member. Coils 32 have a diameter D3 and a thickness D6. Coil 320 has a diameter D5 as shown in Figure 4. End 33 may be angled somewhat inward toward the fastener to allow edge 34 of end 33 to better engage the fastener. This enhances the capacity of the third member coils to grip the fastener. In other applications end 33 need not be angled. Third member may comprise any material capable of gripping fastener sufficient to generate the torques as described herein. For example, third member 30 may comprise a metallic material such as spring steel, steel, or aluminum. It may also comprise non-metallic materials such as plastic, ceramic or polyurethane, as well as combinations or equivalents of either the metallic or non-metallic materials.

Figure 6 is a cross-sectional view of an alternate coil member in Figure 7. Alternate third member 30 comprises coils 32 as described in Figure 4. However, in this alternate embodiment end 31 is omitted. Retention of third member 30 in sleeve 20 is accomplished by a frictional fit of coil 320 in recess 220, please see Figure 8. Namely, coil 320 has an outside diameter D7 that is slightly larger than the inside diameter D4 , see Figure 2, of sleeve 20.

For this embodiment, a frictional fit is achieved between third member 30 and sleeve 20 by the snug fit between coil 320 and recess 220. As fastener 10 is turned, the frictional fit between fastener 10 and coil 320, and of coil 320 with sleeve 20 causes sleeve 20 to rotate in receiver portion 40. Sleeve 20 rotates until surface 24 engages component 50 as described elsewhere in this specification. The turn direction of coil 30 is preferably the same hand as the insertion rotation direction of fastener 10.

For removal, the frictional engagement of coil 30 with recess 220 causes coil 30 to turn sleeve 20, thereby "backing" sleeve 20 out of contact with component 50 as fastener 10 is unscrewed and removed. This illustrates the reusable feature of the inventive device as it can then be reinserted and withdrawn from its installed location as often as required.

Figure 7 is a plan view of an alternate coil member. End 31 is omitted from member 30, but it is otherwise as described in Figure 5.

Figure 8 is a cross-sectional view of an alternate sleeve. Recess 220 comprises a diameter D4 as shown in Figure 2. In this embodiment sleeve 20 does not include receiving portion 23.

Figure 9 is a perspective view of an alternate sleeve. Threads 21 are shown extending along the entire axial length of sleeve 20. Receiving portion 23 is omitted from this embodiment .

To illustrate the benefits of the invention the following information is offered. It is not offered as a limitation on the breadth of the invention. The following values are approximate and will vary depending upon the component design and service conditions.

Third member coils (32) -1.5 Fastener shank diameter (D5) 6.9 mm Fastener nominal diameter 8.00 mm

Third member ID (D3) 6.65 mm

Coil wire diameter (D6) 1.0 mm

Install torque (Direction Rl) 0.16 Ncm Extract torque (Direction R2) 0.48 Ncm

One can see that the installation torque, that is, the torque required to install sleeve 20 into receiver portion 41 is less than the torque required to^" back the fastener 10 out of sleeve 20. During installation sleeve 20 will screw into receiver portion 41 until it "bottoms" on surface 24. Fastener 10 will then continue to turn within third member 30 as described. Extraction of fastener 10 from receiver portion 51 will cause third member 30 to grip fastener 10 thereby- causing sleeve 20 to be extracted from receiver portion 41.

The inventive connector may also be used to speed machine assembly and reduce machining costs. Namely, when two machined castings or fabrications are bolted together the surfaces to be joined are usually machined flat to assure a proper fit-up. A seal or sealant is used between the two surfaces. This requires a surface finish and flatness that can only achieved by machining. This requires time and specialized equipment. The machining of castings usually results in some distortion taking place when stresses on the outer ^Λskin' of the casting are removed. On larger castings sometimes a second pass is required to take out the distortion produced by the first machining pass. Where no seal is required, or, where the required sealing could be achieved in another way, then there is the possibility of eliminating the machining of the surfaces to be joined with associated cost savings. Instead of machining flat spaces, spot-faced bosses for tapping's and dowels are used on the component surfaces to control lateral movement and for proper fitment and alignment. Variations in spacing or gap between the surfaces is accommodated by use of the inventive connectors. Further, use of the inventive connector allows the parts to be later disassembled, for example for maintenance purposes, because the connector is reusable.

Although a form of the invention have been described herein, it will be obvious to those skilled in the art that variations may be made in the process and construction and relation of parts without departing from the spirit and scope of the invention described herein.

Claims

Claims We claim:

1. A tolerance compensating connector comprising: a first member having a threaded portion; a second member comprising a bore and an outer surface, the outer surface having a helical thread engagable with a receiver; the first member engaged with the bore; a third member engaged with the first member and the second member, the third member transmitting a torque from the first member to the second member such that a first torque transmitted to the second member as the first member is turned in a first direction is sufficient to turn the second member in the receiver, the third member having a slipping engagement with the first member when the first torque is exceeded; and upon the first member being turned in a direction opposite the first direction the third member transmits a second torque to the second member sufficient to turn the second member in the receiver in a direction opposite the first direction.

2. The tolerance compensating connector as in claim 1, wherein the third member comprises a coil .

3. The tolerance compensating connector as in claim 1, wherein the first member comprises a threaded fastener.

4. The tolerance compensating connector as in claim 1, wherein the first member threaded portion and the outer surface helical thread are the same hand.

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5. The tolerance compensating connector as in claim 1, wherein the first torque is less than the second torque.

6. A tolerance compensating connector comprising: a threaded fastener; a sleeve portion having an outer threaded portion and a bore; the fastener engaged with the sleeve portion through the bore ; a coil member; and the coil member engaged between the fastener and the sleeve portion, the coil member gripping the fastener to transmit a first torque to the sleeve portion when the fastener is rotated in a first direction, the coil member slipping on the threaded fastener when the first torque is exceeded; and the coil member gripping the fastener to transmit a second torque to the sleeve portion when the fastener is rotated in a second direction.

7. The tolerance compensating connector as in claim 6, wherein the threaded fastener threads and the outer threaded portion threads have the same hand.

8. The tolerance compensating connector as in claim 6, wherein the coil member comprises a non-metallic material .

9. The tolerance compensating connector as in claim 6, wherein the first torque is less than the second torque.

10. The tolerance compensating connector as in claim 6, wherein the first torque is greater than the second torque .

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11. A tolerance compensating connector comprising: a threaded fastener; a sleeve portion having an outer threaded portion and a bore; the fastener engaged with the sleeve portion through the bore; a coil member; the coil member engaged between the fastener and the sleeve portion whereby a torque is transmitted from the fastener to the sleeve portion, the torque dependent upon the direction of rotation of the fastener.

12. The tolerance compensating connector as in claim 11, wherein the coil member has a slipping engagement with the fastener when a predetermined torque is exceeded.

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