CA2224538A1 - Torque gauge assembly - Google Patents

Abstract

Improved retaining means for holding a first object to a second object in tight fitting engagement to constitute a torque gauge assembly, said retaining means comprising a first member having a cylindrical portion having a screw-threaded surface and a head portion; a second member having a portion defining a screw-threaded surface complimentary to and cooperable with said threaded surface of said first member;whereby said first member operably receives said second member to retain said first object to said second object in tight-fitting engagement, the improvement comprising a disc-shaped member having a portion defining an aperture by which said disc-shaped member is received by said first member; and first visible marking to denote a reference mark. The retaining means provides visible detection of its loosening under vibrationary forces. The retaining means is of particular value in detecting loose nut and bolt assemblies used to hold wheels to vehicles.

Description

CA 02224~38 1997-12-09 TORQUE GAUGE ASSEMBLY

FELD OF T~E INVENTION

This invention relates to a torque gauge assembly for the visual detection of the tightness of nut and bolt, stud, screw and other ret~ining assemblies that may be loosened 10 by vibration on vehicles, industrial equipment and railway tracks; and particularly nut and bolt assemblies used for ret~inin~ vehicle wheels on axles.

BACKGROUND OF T~E lNVENTION

Vehicle and other equipment inspection in the transportation industry is mandatory in most jurisdictions. Drivers operating a commercial motor vehicle must do a pre-trip inspection, including the wheel/axle assembly, every shift before taking a vehicle out onto the road. Under the labour codes of most jurisdictions, all equipment in a factory must be inspected for safe operation by the operator or Safety Inspector each 20 shift, day, week or month. In the Province of Ontario, Canada, the operator of a vehicle that loses a wheel may be pen~ e~l by a fine of up to $50,000 "on the spot" and a loss of C.V.O.R. points under the National Safety Code.
Unfortunately, there is no fast, accurate or reliable method of knowing whether a wheel has started to loosen. One method is to hit the wheel with a hammer and listen to 25 the sound to determine in a grossly quantitative manner whether the wheel is "loose" or not. Thus, although a torque wrench is used to make sure a nut is put on at a correct tension wherein the wheel is installed on the axle, there is no ready, fast and convenient way of monitoring its tightness after some use. A plastic cap bearing a mark to show that a nut has started to loosen has been used. However, to replace a wheel or other 30 equipment requires to cap to be prised off with pliers or a sharp tool that invariable destroys the cap.

CA 02224~38 1997-12-09 As a nut and bolt or stud are tightened to clamp two or more plates together, the thread angle in the bolt converts the force applied into tension (or stretch) in the bolt shank. The amount of tension created in the bolt is critical and having no ready idea of the loss of tension requires many hours of checking and re-checking of the nut and bolt assembly every day, month or year. For example, truck wheels may have up to ten nuts and bolts to each wheel and tractor trailers have as many as thirty wheels, which amount to 300 nut and bolt assemblies. Each nut and bolt assembly has to be checked every day and some drivers may have to check up to ten trailers a shift.
There is a need, therefore, for a rapid, easy, cheap and reliable inspection method for determining the tightness of retaining systems such as nuts and bolts, studs, screws and the like for retaining two or more members, directly or indirectly, together and which are prone to loosening under vibration.

SUMMARY OF THE INVENTION

It is the main object of this invention to provide a visual inspection of nuts - bolts - screws that may be loosened by vibration on vehicles or any industrial application to reduce major areas of concern for safety that can use visual inspection.
Thus, the present invention allows for the visual inspection of the degree of tightness of a retaining system of use in vehicles, such as trucks, buses, aircraft, cars, trailers, and in railway tracks, industrial stamping, printing, filling equipment, electric motors, computers, printers, diesel and gas engines air compressors turbines and the like that requires correct optimum torque/tension for each fastening. If the tension between 25 the retaining members, because of vibration, is reduced the assembly of the invention allows an operator to visually see and reset the nut, screw, bolt or the like to its correct setting.
Accordingly, the invention provides Improved retaining means for holding a firstobject to a second object in tight fitting eng~gement to constitute a torque gauge 30 assembly, said retaining means comprising a first member having a cylindrical portion having a screw-threaded surface and a head portion;

CA 02224~38 1997-12-09 a second member having a portion defining a screw-threaded surface complimentary to and cooperable with said threaded surface of said first member;whereby said first member operably receives said second member to retain said first object to said second object in tight-fitting engagement, the improvement comprlsmg (a) a disc-shaped member having (i) a portion defining an aperture by which said disc-shaped member is received by said first member; and (ii) first visible m~rking to denote a reference mark.
In a further aspect the invention provides improved retaining means for holding a first object to a second object in tight fitting engagement, said retaining means comprising:
a first member having a cylindrical portion having a screw-threaded outer surface and a head portion having a planar surface;
a second member having a portion defining an aperture having a screw-threaded inner surface complimentary to and cooperable with said threaded outer surface of said first member;
whereby said first member operably receives said second member to retain said first object to said second object in tight-fitting engagement, the improvement comprlsmg (a) a disc-shaped member having (i) a portion defining an aperture by which said disc-shaped member is received by said first member;
(ii) first visible m~rking to denote a reference mark;
said second member having a second visible m~rkin~ relative to said first visible m~rking when said disc-shaped member is retained on said first member by said second member in pre-determined tight-fitting engagement Preferably, the invention in a further aspect provides improved retaining means 30 for holding a first object to a second object in tight fitting engagement to constitute a torque gauge assembly, said ret~ining means comprising a first member having a cylindrical portion having a screw-threaded outer surface and a head portion;

CA 02224~38 1997-12-09 a second member having (a) a body, (b) a central aperture having a screw threaded inner surface complimentary to and cooperable with said threaded outer surface of said first member; (c) a disc shaped portion having one or more firstvisible m~rkingc to denote one or more reference markings; and one or more second visible m~rking~ on said assembly other than said second member and relative to said first visible marking when said second member is retained on said first member in pre-determined tight fitting engagement, whereby said first visible m~rking and said second visible m~rking are displaced relative one to the other when said assembly loosens.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be better understood, preferred embodiments will15 now be described by way of example only, with reference to the accompanying drawings, wherein Fig. 1 is a diagrammatic side view of a socket wrench combination, partly cut away, and a torque gauge system according to the invention;
Fig. 2 is a front diagrammatic view of a tightened nut, bolt and gauge assembly according 20 to the invention;
Fig. 3 is a diagrammatic side view of an integrally formed nut and gauge component for use in an embodiment according to the invention;
Fig. 4 is a diagrammatic side view of an integrally formed bolt and gauge component of use in an alternative embodiment of a torque gauge assembly according to the invention;
25 Fig. 5 is a diagrammatic side view of an integrally formed self-locking torque screw and gauge component of an alternative embodiment according to the invention;
Fig. 6 is a perspective view of a torque gauge assembly according to the invention in a pre-assembled mode;
Fig. 7 is a perspective view of the general embodiment shown in Fig. 6 in a tightened 30 mode;
Fig. 8 is a perspective view of an integrally formed neck and gauge shoulder component of use in an alternative embodiment according to the invention;

CA 02224~38 1997-12-09 Fig. 9 is a perspective view of an alternative embodiment according to the invention wherein a washer constitutes a protective gauge m~rking neck;
Figs. 10 and 11 represent diagrammatic side elevational views of steel backing plates of S casings for retaining vibration prone electrical components;
Fig. 12 is an enlarged diagrammatic front view of a torque gauge assembly of Fig. 11;
Fig. 13 is a diagrammatic plan view of a railway track incorporating the torque gauge assembly according to the invention;
Fig. 14 represents a diagrammatic plan view of a scanner beam em:~n~ting from a moving 10 train shining on a nut and bolt torque gauge assembly, according to the invention; and Fig. 15 represents a diagrammatic side view of a nut and bolt torque gauge assembly according to the invention having a bar code gauge indicia.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to Fig. 1, this shows a torque wrench generally as 10 having a shaft 12, a gauge 14 and head 16 engageable with a socket 18, partly cut away, through mating balls 19 and sockets (not shown). Socket 18 engages a hardened steel threaded nut 20 loosely threaded as shown on a hardened steel screw-threaded stud 22 for the 20 purpose of subsequent abutmen, one retention of metal plates 24 to metal plate 26 in tight to the other. Disposed between nut 20 and plate 24 is a steel circular disc 28 having a central aperture 30 which receives steel shank 32. Disc 28 has a planar circular body 34 and a planar circular raised neck 36 of smaller diameter to provide an annular planar face 38 having a plurality of raised engraved m~rking numerals constituting a gauge 40 25 designating a scale of the degree of tightness of nut 20 and stud 22.
In operation, nut 20 is tightened on stud 22 to retain plates 24, 26 together to a desired torque value, typically, a value selected from 300 - 500 foot/lbs. A fine luminescent paint line 41 in Fig. 2 is then marked on face 42 of plate 24 adjacent the appropl;ate gauge m~rking foot/lb numeral denoting the tightness of the nut and bolt 30 assembly.
The raised gauge m~rkings in this embodiment are preferably also coated with a suitable, visible paint. In an alternative embodiment, the m~rking.~ may constitute CA 02224~38 1997-12-09 etchings or depressions in annular face 38. Disc 28 has neck 36 formed of any suitable shape to provide a protective means for preventing the stripping or other damage to face 38 or its m~rking~. In alternative embodiments, the m~rking~ may be represented on S suitable marked discs formed of aluminum, plastics material, waterproof paper, retained between plate 24 and nut 20.
Fig. 2 shows a torque gauge assembly of the invention in a tightened operationalmode and having stud shock 32 protruding through nut 20. Face 38 has visible m~rking~
40 and face 42 of plate 24 has a paint line 41 in line with a desired setting. Loosening of nut 20 on stud 22 will cause origin~ting m~rking line to be displaced from paint line 41.
Fig. 3 represents generally as 48 an hardened steel hexagonal inner-screw threaded nut 50 integrally formed with a disc 52 through having tightness markings gauge 54 on its upper surface 56, through a protective neck 58.
In operation, integrally formed nut and gauge component 48 is threaded onto a l S stud, bolt or the like to the desired tightness to effect abutment of two planar members (not shown). The visible surface of the planar member adjacent disc 52 is suitably marked with a paint line.
Fig. 4 shows generally as 60 a fully integrally formed hardened steel bolt and gauge component having a bolt head 62, a threaded boy 64 and an intervening gauge protective neck 66 on a shoulder 68 having an upper surface 70 with raised gaugem~rking~ 72. Bolt body 64 is threaded onto a nut with a pair of intervening planar members therebetween to be tightened thereon (not shown).
Fig. S shows generally as 80, a fully integrally formed metal screw and gauge component having a flat-headed screw head 82 with screwdriver slot 84. Head 82 is formed with threaded body 86 through protective neck 88 and shoulder 90 is screwed into plates 96, 98 to a desired degree of tightness and a suitable paint line marked on the upper surface 100 of plate 96.
Figs. 6 and 7 show a hexagonal bolt generally as 110 having a head 112 and threaded body 114 to be used to retain two metal plates 116, 118 together with acomplementary nut (not shown). Each of plates 116, 118 has bolt holes (not shown) to receive bolt body 114. Plate 118 has an upper face 120 abutable with the backside face of a circular disc gauge member shown generally as 122. Member 122 has a body 124 CA 02224~38 1997-12-09 and an integrally formed circular 126 neck of smaller diameter. Body 124 and neck 126 have central apertures 127, 130, respectively, to receive bolt body l 14. Body 122 has an annular face 132 bearing raised gauge m~rking~ 134. Thus, in operation, tightening of bolt l l 0 causes plates l l 6, 118 and gauge component 122 to be tightly abutted, one to the others, with the m~rking~ fixed in a desired position. A corresponding paint line 136 is provided on face 128 adjacent to the desired torque value on the gauge. Loosening of the assembly breaks this torque line relationship.
Fig. 8 shows a circular metal disc generally as 140 having a body 142, integrally l0 formed neck 142 and central bolt receiving aperture 146. Gauge markings 148 are embossed on annular surface 150 defined by the respective circumferences 152, 154 of body 142 and neck 144.
In alternative embodiments, the protective neck may be a non-integrally formed washer or the like. Fig. 9 shows such a washer 160 on a self-locking torque screw 162, as 15 a protective neck for circular marked gauge plate 164 abutable with plate 166.
In an alternative embodiment, the head of the bolt, stud, screw and the like per se may be marked with the gauge m~rking~ in the form of paint mark, such as a spot, line and the like, raised protrusions embossings eteched, cuttings and the like.
In a further embodiment of the assembly according to the invention the head of 20 the nut, stud, screw and the like may be marked with a paint line after tightened assembly, rather than the surface of the plate in abutment, and any subsequent displacement of the paint line on the head relative to the gauge scale indicia visually observed. This would not result in defacement of the plate surface. The gauge indicia may also be represented as edge m~rkings, such as protrusions, serrations, cuttings or the 25 like on the actual circumference of the abutable plate member.
For duties requiring only low torque values of, for example, 1 - 50 ft/lbs., self-adhesive paper type gauges may be employed. Such duties may include vibration-prone electrically operated equipment, such as electric motor driven systems.
Another duty for the torque-gauge assembly according to the invention is on train 30 track fittings requiring nut and bolt linkage of one rail to an adjoining rail. One advantage gauge in this duty constitutes an extremely fast readable bar code read and suitably identified by a passing scanner on a train travelling on the rails.

CA 02224~38 1997-12-09 Typically, the torque gauge assembly of the invention is read in the order reverse to normal reading, since a detection of a decrease in the tightness index is to be noted.
The paint line reading on the surface of the abuting object starts from a higher5 reading and registers a lower one when the nut loosens, and, thus, it is the nut/gauge component ~ se which indicates by movement thereof reduced torque of the assembly.
Fig. 10 shows generally a steel plate with plurality of holes 147, three of which 148 are without screws 184 but has flat head screws 184 inserted into holes 47 provided with gauge m~rkingc 172 pre-stamped into the steel plate 140. Regular flat head screw 84 is tightened and marked with paint to correlate with m~rkingc 172 on steel plate at a prescribed torque.
Fig. 11 shows generally a steel plate 240 that has a number of screws 272 havingraised gauge m~rking.c 222 shows screws displaced 242 is a hole to except screw 241 being a paint line at a desired setting. Fig. 12 shows an enlargement of a single segment hole with screw as in Fig. 11 with a paint line displaced showing loosened screw.
Fig. 13 shows a pair of railway rails 302, 304 on sleepers 306 and jointed by rail ties shown generally as 308, 310. Ties 308 hold adjacent rails 302 together by nut 312 and bolt 314 assemblies, typically, four pairs of nuts and bolts per side of each rail track.
Nut 312 has an integrally formed shoulder 316 having a visible surface 318 bearing a bar code indicia readably by scanner 320 located on steel arms attached to a rail car (not shown) and mounted as to pass in parallel to rail ties 308.
Electronic bar code scanner 300 will record movement of nuts 312 or 314 bolts relative one to the other or m~rking on ties 308. Fig. 15 shows various types of bar codes, 322, 324 or 326.
Scanner 320 can store information on a disk that can be read at the end of the trip and record date location and severity of loss of torque. To confirm nut and bolt tightness, when going to a location that was recorded by a scanner, an inspector may use a hand held scanner unit to locate the rail tie to be fixed.
Although this disclosure has described and illustrated certain preferred embodiments of the invention, it is to be understood that the invention is not restricted to those particular embodiments. Rather, the invention includes all embodiments which are functional or mechanical equivalents of the specific embodiments and features that have been described and illustrated.

Claims (22)

1. Improved retaining means for holding a first object to a second object in tight fitting engagement to constitute a torque gauge assembly, said retaining means comprising a first member having a cylindrical portion having a screw-threaded surface and a head portion;
a second member having a portion defining a screw-threaded surface complimentary to and cooperable with said threaded surface of said first member;whereby said first member operably receives said second member to retain said first object to said second object in tight-fitting engagement, the improvement comprising a disc-shaped member having -a portion defining an aperture by which said disc-shaped member is received by said first member; and first visible marking to denote a reference mark.

2. Improved retaining means for holding a first object to a second object in tight fitting engagement, said retaining means comprising a first member having a cylindrical portion having a screw-threaded outer surface (and a head portion having a planar surface);
a second member having a portion defining an aperture having a screw-threaded inner surface complimentary to and cooperable with said threaded outer surface of said first member;
whereby said first member operably receives said second member to retain said first object to said second object in tight-fitting engagement, the improvement comprising (b) a disc-shaped member having (iii) a portion defining an aperture by which said disc-shaped member is received by said first member;
(iv) first visible marking to denote a reference mark;

(c) a second visible marking on said assembly relative to said first visible marking when said disc-shaped member is retained on said first member by said second member in pre-determined tight-fitting engagement, whereby said first visible marking and said second visible marking are displaced one relative to the other when said assembly loosens.

3. Retaining means as defined in claim 1 or claim 2 wherein said first member is integrally-formed with said second object.

4. Retaining means as defined in claim 1 or claim 2 wherein said first visible marking comprises a plurality of designations disposed in an arcuate arrangementto constitute an arcuate scale on said disc-shaped member.

5. Retaining means as defined in claim 1 or claim 2 wherein said disc-shaped member is formed of a plastics material, metal or metallic foil.

6. Retaining means as defined in claim 4 wherein said disc-shaped member is adhered to said second object.

7. Retaining means as defined in claim 1 or claim 2 further comprising an intervening member in the form of a metallic second disc-shaped member having a central aperture by which it is received by said first member disposed betweensaid second member and said disc-shaped member in tight-fitting engagement.

8. Retaining means as defined in claim 3 wherein said arcuate scale is calibrated in values denoting the torque between said first and said second members.

9. Retaining means as defined in claim 1 or claim 2 wherein said first visible markings are selected from the group consisting of coloured lines symbols, indicia, grooves, apertures, slots and circumferential notches.

10. Retaining means as defined in claim 1 or claim 2 wherein said first member and said second member comprise a nut and bolt assembly.

11. Retaining means as defined in claim 3 wherein said second object comprises a planar surface having a plurality of integrally-formed first members.

12. Retaining means as defined in claim 10 wherein said second object comprises axle retaining means and said first object comprises a wheel hub.

13. A wheel and hub assembly comprising a plurality of retaining means as defined in claim 1.

14. A disc-shaped member having a first side having a first planar surface, a second side having to said first side and a second planar surface reverse to said firstplanar surface and having a plurality of arcuate markings and a substantially central aperture.

15. A member as defined in claim 14 wherein said plurality of markings are selected from the group consisting of coloured lines, indicial, symbols, grooves, apertures, slots and circumferential notches.

16. A member as defined in claim 14 formed of a material selected from the group consisting of a plastic material, metallic foil, cardboard and paper.

17. A member as defined in claim 14 wherein said second planar surface has an adhesive coating having a peelable protective layer

18. Improved retaining means for holding a first object to a second object in tight fitting engagement to constitute a torque gauge assembly, said retaining means comprising a first member having a cylindrical portion having a screw-threaded outer surface and a head portion;
a second member having (a) a body, (b) a central aperture having a screw threaded inner surface complimentary to and cooperable with said threaded outer surface of said first member; (c) a disc shaped portion having one or more firstvisible markings to denote one or more reference markings; and one or more second visible markings on said assembly other than said second member and relative to said first visible marking when said second member is retained on said first member in pre-determined tight fitting engagement, whereby said first visible marking and said second visible marking are displaced relative one to the other when said assembly loosens.

19. Retaining means as defined in claim 18 wherein said second member is a nut and said second member is a bolt, stud or screw.

20. Retaining means as defined in claim 18 or claim 19 wherein said first visible markings comprise a plurality of markings selected from the group consisting of designations, symbols, indicia, grooves, apertures, indicia, slots and circumferential notches, disposed in an arcuate arrangement to constitute an arcuate scale on said disc-shaped portion.

21. Retaining means as defined in any one of claims 18 to 20 wherein said first object is the hub of a wheel, said second object is an axle assembly for cooperating with said wheel, said first member is a stud; said head is the backing plate of said axle assembly to which said hub is held by said retaining means, and said second member is a retaining nut for retaining said hub adjacent in pre-determined tight fitting engagement to said backing plate; and wherein said backing plate bears said visible second markings.

22. An inner screw-threaded nut for use with a bolt, stud or screw having a complementary outer screw threaded shank, said nut comprising an integrally formed disc portion having a circumferential edge and surface, said edge or surface bearing a plurality of arcuate markings denoting a torque gauge scale.