Bolt and nut lock assembly

Abstract: A bolt lock assembly (40) and a nut lock assembly (60) are provided that respectively include a collar member (16) that is movable in opposite axial directions in a counterbore (12) in an object (4) and is biased outwardly therefrom by a coiled spring (20). Counterbore (12) has at least one slot (14) extending radially outwardly therefrom and collar member (16) has at least one locking member (18) extending therefrom having a portion registerable with and remaining in slot (18) and a portion adapted to engage locking surfaces on a bolt head (6) of bolt (2) or a nut (24) when collar member (16) is urged outwardly from counterbore (12) to provide the locked engagement therebetween.

Description: INTRODUCTION This invention relates generally to an assembly operative to releasably lock either a bolt to an object or a nut to a threaded shank extending from an object to prevent unintended loosening. BACKGROUND OF THE INVENTION US-A-4 534 101 discloses an arrangement for securing a nut against rotation. To this end the bore within the object through which the bolt extends is provided with a counterbore. The inwardly facing side wall of the counterbore includes a plurality of axially extending slots or grooves evenly distributed along the peripherie of the counterbore. The nut comprises a substantially cylindrical portion which is arranged beneath the hexagonal head and separated from that head by a radially extending shoulder going beyond the peripherie of the cylindrical portion. Adjacent to the shoulder the cylindrical portion which is substantially smaller in diameter than the inner diameter of the counterbore is also provided with a plurality of axially extending grooves. The cylindrical portion of the nut and the wall of the counterbore define an annular space wherein an annular locking or securing member is situated. This annular member carries two groups of axially extending teeth or splines one group of which extend radially inward and cooperate with the grooves of the nut whereas the other one projects radially outwardly and lie in grooves provided on the inner surface of the counterbore. This arrangement requires a special type of tool which allows for pressing down the ring in order to disengage same from the grooves of the nut and allow the nut to be rotated. A variety of devices have been developed over the years to prevent bolts from loosening from whatever they are threaded into and to prevent nuts from loosening from bolts onto which they are threadingly secured. One example of a bolt lock device is disclosed in United States Patent 2,370,223, the disclosure of which is incorporated herein by reference. The device however, is highly complex and requires two counteracting coiled springs in order to provide its locking function. Examples of nut locking devices such as lock washers having one or more tongues or gripping elements that engage a side of the nut to prevent it from rotating are respectively disclosed in United States Patents 424,836 and 2,151,919, the disclosures of which are incorporated herein by reference. In the nut lock of the 424,836 patent, the locking tongues would have to be bent outwardly after the nut is secured to the bolt and then forcibly flattened before the nut could be loosened. The locking device in the 2,151,919 patent relies upon friction and may not prevent the nut from loosening under certain circumstances. Examples of nut locks employing coiled springs are respectively disclosed in United States Patents 900,589 and 1,763,505, the disclosures of which are incorporated herein by reference. Both however, are highly complex and would not readily lend themselves both as a bolt lock and as a nut lock. SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide a selectively releasable bolt and nut lock assembly that is highly effective in locking a bolt to an object and for locking a nut to a bolt shank and to an object from which the bolt shank extends. It is another object of this invention to provide a bolt and nut locking assembly that is easy to operate and is relatively simple in design. To attain these objects a bolt lock assembly for releasably locking a bolt to an object and a nut lock assembly for releasably locking a threaded nut to an object comprise the features of claims 1 and 2, respectively. BRIEF DESCRIPTION OF DRAWINGS FIGURE 1 is an exploded perspective view of a bolt lock assembly 40 of the invention; FIGURE 2 is an exploded perspective view of a nut lock assembly 60 of the invention; and FIGURE 3 is a perspective view of another embodiment of a collar member 16 used in assembly 40 of FIGURE 1 and in assembly 60 in FIGURE 2. DESCRIPTION OF SOME PREFERRED EMBODIMENTS Assembly 40 shown in FIGURE 1 is a bolt lock assembly operative to releasably lock bolt 2 to an object 4 which may, of course, be a singular object to which bolt 2 is to be releasably locked or may be two or more objects such as plates that are to be secured together by bolt 2. Bolt 2 has an enlarged head 6 from which extends a substantially tubular or stud shank 8 that is at least partially threaded. Object 4 has a bore 10 therein that may or may not be threaded such as where shank or stud 8 is to pass through object 4 into a threaded bore of an adjacent object to be secured to object 4 o,r in instances where a threaded nut is used, to secure bolt 2 on the opposite side which may itself be releasably locked to the opposite side of object 4 or to any intermediate objects therebetween secured together by bolt 2 by utilizing the nut lock assembly of the invention hereinafter described with respect to assembly 60 of FIGURE 2. A counterbore 12 of predetermined axial length is disposed in object 4 in substantial axial alignment with bore 10. Counter bore 12 has a larger diameter than the diameter of bore 10 defining a substantially annular shoulder 7 at the intersection therebetween that faces away from bore 10 towards counterbore 12 as shown in FIGURE 1. Object 4 is characterized by including at least one slot 14 that extends outwardly from the periphery of counterbore 12. Object 4 preferably includes a plurality of slots such as slots 14 and 14' that extend outwardly from substantially diametrically opposite sides of the periphery of counterbore 12. Slots 14 and 14' extend for a distance sufficient to ensure that a portion remains exposed outwardly of bolt head 6 when bolt head 6 is aligned with counterbore 12 and brought into close proximity thereto or, more simply stated, that they extend for a predetermined radial distance beyond the breadth of bolt head 6. Assembly 40 has a collar number 16 having an opening (not referenced) for receiving shank 8 of bolt 2 therethrough. Collar member 16 is adapted to be received into and be able to move in opposite axial directions within Counterbore 12. Collar member 16 is provided with at least one locking member extending outwardly therefrom, preferably in the form of tab 18, that is adapted to register with and be received into slot 14 or additional slots such as slot 14' when such are included. Collar member 16 preferably has two locking members, preferably in the form of tabs 18 and 18' extending outwardly therefrom that, as in the case of slots 14 and 14' extend radially outwardly from collar member 16 for a distance sufficient to insure that a predetermined portion thereof remains exposed outwardly of bolt head 6 when bolt head 6 is axially aligned with counterbore 12 and brought into close proximity thereto. A portion of locking members 18 and 18' is adapted to lockingly engage locking means provided on bolt head 6, as hereinafter described, to provide locked engagement between bolt 2 and object 4. Resilient biasing means, such as coiled compression spring 20, is disposed within counterbore 12 with one end resting on shoulder 7 and the opposite end engaging the end of collar member 16 facing theretowards. Spring 20 has an aperture (not referenced) for receiving shank 8 therethrough from the opening through collar member 16 to enable it to be received into bore 10. Spring 20 and collar member 16 are respectively adapted such that spring 20 is able to urge collar member 16 axially away from shoulder 7 for a distance exposing a predetermined portion of locking members 18 and 18' outwardly of slots 14 and 14'. Locking members 18 and 18'; slots 14 and 14'; counterbore 12; and collar member 16 are adapted such that locking members 18 and 18' can be respectively pressed inwardly into slots 14 and 14' sufficiently to ensure that bolt head 6 can be brought into predetermined proximity to object 4 without entering into locked engagement with locking members 18 and 18'. The preferred locking means provided bolt head 6 is in the form of at least one channel 9 disposed in a side of bolt head 6 facing towards shank 8. Preferably, bolt head 6 is provided with a plurality of channels 9 that are disposed substantially circumferentially equi-distant from each other and that are adapted to respectively register with and receive a portion of locking members 18 and 18' thereinto to provide the releasably locked engagement between bolt 2 and object 4. In operation, spring 20 is inserted into counterbore 12 followed by collar member 16 oriented so that locking member 18 is received into slot 14 and locking member 18' is received into slot 14'. Shank 8 of bolt 2 is inserted through the opening through collar member 16 and the aperture through spring 20 and into bore 10. In the case where bore 10 has threads operable to threadingly engage the threads on shank 8, bolt 2 is rotationally threaded into bore 10 by a wrench or the like. Pressing the exposed portions of tabs 18 and/or 18' inwardly into slots 14 and 14' by hand or by the wrench enables bolt head 6 to advance into predetermined close proximity to slots 14 and 14' in object 4, which may be virtually a flush surface to surface contact at which time tabs 18 and 18' are released and bolt head 6 rotated to bring diametrically opposite channels 9 into registration therewith, at which point, spring 20 operates to urge a portion of tabs 18 and 18' into the channels 9 whilst ensuring that a portion thereof respectively remain in slots 14 and 14' to provide the releasable locked engagement between bolt 2 and object 4. The locked engagement between bolt 2 and object 4 is easily released since portions of tabs 18 and 18' remain exposed outside the breadth of bolt head 6 which can be pressed inwardly sufficiently to release tabs 18 and 18' respectively from channels9 to enable bolt 2 to be rotatingly removed from bore 10. Assembly 60 of FIGURE 2 operates on essentially the same principle hereinbefore described for assembly 40 except that assembly 60 is a nut lock assembly being used to releasably lock a nut 24 to object 4 that is threadingly engaged to an externally threaded shank extending outwardly from counterbore 12. As previously described with respect to object 4 for assembly 40, bore 10 in object 4 (not shown in FIGURE 2) may be threaded such that shank 8 is threaded through bore 10 from an opposite side of object 4 or through one or more objects being joined together by shank 8 and nut 24. The operation of locking and releasing nut 24 from object 4 is essentially the same as hereinbefore described for assembly 40 of FIGURE 1 and is therefor not repeated here. In FIGURE 3, collar member 16 is provided with another embodiment of locking members than tabs 18 and 18' hereinbefore described by having at least one and preferably two diametrically opposed locking members extending outwardly away from collar member 16 having respective portions 26 and 26' adapted to register with and be respectively received into slots 14 and 14' and which respectively further includes fingers 28 and 28' extending respectively therefrom that are adapted to move outwardly away from counterbore 12 and engage a flat section, such as section 30 on nut 24 or section 32 on bolt head 6, whilst portions 26 and 26' remain in slots 14 and 14' respectively to provide the locking engagement between object 4 and bolt 2 or nut 24 as the case may be.

Claims: A bolt lock assembly(40) for releasably locking a bolt(2) to an object(4), said bolt having an enlarged head(6) having an at least partially externally threaded shank(8) extending therefrom, said object(4) having a bore therein and a counterbore(12) having a larger diameter substantially axially aligned therewith defining a shoulder(7) at the intersection therebetween facing away from the bore theretowards, said object characterized by having at least one slot(14) extending radially outwardly from the periphery of the counterbore(12) for a distance sufficient to insure that a predetermined portion of thereof remains exposed when the bolt head(6) is in substantial axial alignment with the counterbore(12) and brought into close proximity thereto, and said assembly comprising; a collar member(16) adapted to be received into the counterbore separately from the bolt and operable to move in opposite axial directions relative thereto, said collar member(16) having an opening adapted to receive the bolt shank(8) therethrough, at least one locking member(18) extending outwardly from the collar member(16) and adapted to be received into the slot(14) when in registration therewith and the collar member(16) is received into the counterbore(12) with a portion thereof radially exposed when the bolt head(6) is in axial alignment with the collar member(16) and brought into close proximity thereto, resilient biasing means disposed in the counterbore(12) between the shoulder(7) and the collar member(16) and having an aperture adapted to receive the bolt shank therethrough, said biasing means operative to urge a predetermined portion of the locking member(48) outwardly from the slot(14), and means associated with the bolt head(6) for releasably locking the bolt(2) to the object(4) when the locking member(16) comes into engagement therewith, at least one channel (9) disposed in a side of the bolt head (6) facing towards the shank for releasibly locking the bolt head (6) to the object (4) when the locking member (18) comes into locking engagement with the at least one channel (9). said assembly(40) operable such that, when the bolt shank(8) is inserted through the collar member(16) opening and the resilient biasing means aperture and into the bore, pressing the exposed portion of locking member(16) axially inwardly against the resilient biasing means enables the bolt head(6) to be brought into predetermined proximity to the object(4) and release of the locking member(16) when the bolt head locking means is in substantial registration therewith enables the resilient biasing means to urge a portion of the locking member (18) axially outwardly into the at least one channel (9) whilst a portion thereof remains in the slot (14) to provide the locked engagement between the bolt (2) and the object (4). A nut lock assembly(60) for releasably locking a threaded nut(24) to an object(4), said object(4) having a bore therein and a counterbore(12) having a larger diameter substantially axially aligned therewith defining a shoulder(7) at the intersection therebetween facing away from the bore theretowards. said object(4) having a shank(22) extending from the bore outwardly through the counterbore(12) having threads adapted to threadingly engage the nut threads, and said object(4) characterized by having at least one slot(14) extending radially outwardly from the periphery of the counterbore(12) for a distance sufficient to insure that a predetermined portion thereof remains exposed when the nut(24) is in substantial axial alignment with the counterbore(12) and brought into close proximity thereto, and said assembly(60) comprising; a collar member(16) adapted to be received into the counterbore(12) separately from the nut(24) and operable to move in opposite axial directions relative thereto, said collar member(16) having an opening adapted to receive the shank(22) therethrough, at least one locking member(18) extending outwardly from the collar member(16) and adapted to be received into the slot(14) when in registration therewith and the collar member(16) is received into the counterbore(12) with a portion thereof exposed when the nut(24) is in substantial axial alignment with the collar member(16) and brought into close proximity thereto, resilient biasing means disposed in the counterbore(12) between the shoulder(7) and the collar member(16) and having an aperture adapted to receive the shank(22) therethrough, said biasing means operative to urge a predetermined portion of the locking member(18) outwardly from the slot, and at least one channel (9) in a side of the nut (24) facing towards the object (4) for releasably locking the nut (24) to the object (4) when the locking member (18) comes into locking engagement with the at least one channel (9), said assembly(60) operable such that, when the nut(24) is threadingly engaged with the shank(22), pressing the exposed portion of the locking member(18) inwardly against the resilient biasing means enables the nut(24) to be brought into predetermined proximity to the object(4) and release of the locking member(18) when the nut locking means is in substantial registration therewith enables the resilient biasing means to urge a portion of the locking member(18) outwardly into engagement with at least one channel (9) whilst a portion thereof remains in the slot (14) to provide the locked engagement between the nut (24) and the object (4). The assembly(40,60) of claim 1 or 2 wherein the object has two of the slots(14,14') extending outwardly from substantially diametrically opposite sides of the counterbore(12) periphery and the collar member(16) has two of the locking members (18,18') respectively registerable therewith. The assembly (40) of claim 1, wherein the locking member (18) is a tab having a portion adapted to be received into the channel (9) to provide the locked engagement therebetween. The assembly (40) of claim 2, wherein the locking member (18) is a tab having a portion thereof adapted to be received into the channel (9) to provide the locked engagement therebetween. The assembly(40) of claim 1 wherein the bolt head(6) has at least one flat section(32) on a side thereof and the locking member(16) includes a finger(28) extending therefrom that is operative to engage the flat section(32) to provide the locked engagement therebetween. The assembly(60) of claim 2 wherein the nut has at least one flat section(30) on a side thereof and the locking member(16) includes a finger(28) extending therefrom that is operative to engage the flat section(30) to provide the locked engagement therebetween. The assembly(40,60) of claim 1 or 2 wherein the resilient biasing means is a coiled compression spring(20).

Inventors: RUNELS THOMAS LEE, RUNELS, THOMAS LEE
Applicants: EATON CORP, EATON CORPORATION
Application year: 1990
Main classification: F16B41
IPC codes: F16B37, F16B39