CA1234711A - Stud anchor - Google Patents
Stud anchorInfo
- Publication number
- CA1234711A CA1234711A CA000419510A CA419510A CA1234711A CA 1234711 A CA1234711 A CA 1234711A CA 000419510 A CA000419510 A CA 000419510A CA 419510 A CA419510 A CA 419510A CA 1234711 A CA1234711 A CA 1234711A
- Authority
- CA
- Canada
- Prior art keywords
- collar
- anchor
- shank
- reduced neck
- expansion portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000002184 metal Substances 0.000 claims description 10
- 239000000463 material Substances 0.000 description 7
- 238000003780 insertion Methods 0.000 description 4
- 230000037431 insertion Effects 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 210000002105 tongue Anatomy 0.000 description 3
- 239000002390 adhesive tape Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000007567 mass-production technique Methods 0.000 description 2
- 206010052128 Glare Diseases 0.000 description 1
- 235000009421 Myristica fragrans Nutrition 0.000 description 1
- 244000270834 Myristica fragrans Species 0.000 description 1
- 244000018764 Nyssa sylvatica Species 0.000 description 1
- 235000003339 Nyssa sylvatica Nutrition 0.000 description 1
- 241000282320 Panthera leo Species 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 210000000078 claw Anatomy 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000007730 finishing process Methods 0.000 description 1
- 230000004313 glare Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 239000002674 ointment Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B13/00—Dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose
- F16B13/04—Dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose with parts gripping in the hole or behind the reverse side of the wall after inserting from the front
- F16B13/06—Dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose with parts gripping in the hole or behind the reverse side of the wall after inserting from the front combined with expanding sleeve
- F16B13/063—Dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose with parts gripping in the hole or behind the reverse side of the wall after inserting from the front combined with expanding sleeve by the use of an expander
- F16B13/065—Dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose with parts gripping in the hole or behind the reverse side of the wall after inserting from the front combined with expanding sleeve by the use of an expander fastened by extracting the screw, nail or the like
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Dowels (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An anchor having a shank, a reduced neck portion and a tapering portion on the inner end, and engagement means on the outer end and having a one-piece wedging collar arranged around the reduced neck portion, and having an overlapping portion extending partially up the tapered portion, and such collar having a leading and a trailing end and an axial slot extending part way therethrough from the leading end, near the tapered portion and terminating at a bridge portion, near the trailing end and at least two generally dome-shaped bosses formed in said collar, extending outwardly, and defining a maximum spacing there between greater than the diameter of the shaft shank of such anchor, the bosses being located between the leading end. and the bridge portion, on either side of the axial slot.
An anchor having a shank, a reduced neck portion and a tapering portion on the inner end, and engagement means on the outer end and having a one-piece wedging collar arranged around the reduced neck portion, and having an overlapping portion extending partially up the tapered portion, and such collar having a leading and a trailing end and an axial slot extending part way therethrough from the leading end, near the tapered portion and terminating at a bridge portion, near the trailing end and at least two generally dome-shaped bosses formed in said collar, extending outwardly, and defining a maximum spacing there between greater than the diameter of the shaft shank of such anchor, the bosses being located between the leading end. and the bridge portion, on either side of the axial slot.
Description
I
The invention relates to an anchor device for use in materials such as concrete, blocks, and certain types of stone.
Background of the Invention A well known form of anchor for concrete employs a shank having a tapered expansion portion in its inner end. An axially movable or wedge collar formed of two pieces of metal is arranged around the -tapered portion and can be expanded outwardly by applying tension along the axis of the anchor. The collar is then wedged outwardly against the concrete or masonry material by the tapered portion.
One form of such an anchor is shown in Canadian Patent No. 766,~93, issued to AGO. McCulloch on September 5, 1967.
One of the problems of that type of anchor was the tact that the collar was formed of two or more separate pieces, which were held in position initially by means of adhesive tape or the like. There was always the possibility for the adhesive tape to become dislodged or damaged, and the collars might simply fall off. When introducing the anchor into a bore hole, in other than ideal conditions, there was also a tendency for the collars to become loosened and lost.
A more serious disadvantage was the fact that the anchor is usually used with some form of threaded attachment means at its outer end. This may take the form of a male thread, or may take the form of a socket, these two being the most popular forms of this type of anchor.
In order therefore to apply the expanding tension along the axis of the anchor, it is necessary for something such as a nut, threaded rod or the like to be attached to the outer end of the anchor. However, in this type of anchor there was no structure to prevent rotation of the entire anchor.
If this occurred, then the threaded fastening device at its outer end could only be tightened up with the greatest difficulty.
An improved form of anchor is shown in Canadian Patents 899,669 issued -to R. Seetaram on May 9, 1972 and 953,958, issued to JO Seetaram on September 3, 1974.
In this type of anchor the wedge on the collar is formed of a single piece of metal, and the tapered expansion portion is formed with some form of collar engagement surfaces either in the form of a flattened portion, or a bed or button or groove. The collar also had outwardly extending tongues for engaging the sides of the hole in the concrete The collar was thus hold by the concrete against rotation. The collar in turn through its engagement with the surfaces on the tapered portion, held the shaft against rotation.
This device was a considerable improvement both in the fact that the collar was made of one piece of metal so that it could not become lost, and also because it was much easier to tighten up when a threaded fastening device was attached to the outer end.
However, it is difficult to manufacture the engagement surfaces and the collar to suitable tolerances in existing mass production techniques, and in practice : ' ~39L7~
either the tolerances become so slack that the engage-mint is not sufficiently secure, or alternatively the costs of production rise to the point where customers will not purchase the anchor.
An additional disadvantage of -this anchor in practice was found to be the fact that the tongues on the collar tended to become deformed as the anchor was driven into the hole in the concrete. As a result, they no longer had the same holding capacity, so that in certain circumstances it was still possible for the entire anchor to rotate.
For all of these reasons therefore it is clearly desirable to provide an anchor having a more secure form of engagement between the collar and the side walls of . the Holland also having a more secure Norm of engage-mint between the collar and the tapered portion of the shaft, so as -to positively resist rotation, and at the same time, being capable of being manufactured by simpler mass production techniques, where critical tolerances do not require to be held to the same degree.
Brief Summary of the Invention With a view to providing the foregoing features in a simplified form of anchor, the invention comprises an anchor having a shank with an inner end and an outer end, a reduced neck portion formed on the inner end, and a tapering portion extending from thy reduced neck, and : having engagement means on the outer end, and a one-piece expansion collar arranged around the reduced neck portion on the inner end, and extending partially up the tapered portion, the collar being formed of a single strip of I
metal having two ends, such collar being formed with said two ends in end a butting relation, and briny spaced apart from one another defining an open gap, and such collar having, in an intermediate portion thereof, an axial slot extending part way there through and defining one open end, the open end being directed towards said tapered portion of said anchor, and there being at least two generally dome shaped bosses formed in said collar, extending outwardly therefrom, and defining a maximum spacing there between greater than the diameter of the shaft shank of such anchor, said collar making a loose fit around said reduced neck portion, and being squeezable there around into a tight frictional engagement thereon with a short portion of such collar extending tightly around portion of such tapered portion, upon engagement of said domelike bosses within the sun-faces of a bore hole.
More particularly, the invention provides such an anchor wherein the two ends of such collar, and the open-ended slot formed in such collar, define at least fur pointed areas overlying part of such tapered portion, such pointed areas being squeezable together upon forcing ' of said anchor into a bore hole, and said pointed areas being thereby forced into engagement with the tapered portion of said shaft adjacent said reduced neck portion, thereby providing a good frictional engagement between said collar and said shaft, whereby to resist rotation of said anchor.
More particularly, the invention provides an anchor having the foregoing advantages, wherein the open-ended slot in said collar defines a predetermined spacing therein, such that when the collar is squeezed I
together around the reduced neck and the tapered portion of the shank, the area of the collar adjacent to the open-ended slot is squeezed inwardly.
The various features of novelty which kirk-Tories the invention are pointed out with particularity in the claims annexed to and forming a part ox this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are ` illustrated and described preferred embodiments of the oven lion .
In the Drawings .
Figure 1 is a perspective illustration of an anchor according to the invention;
Figure 2 is a perspective illustration of the collar of Figure 1 shown in isolation;
Figure 3 is an elevation Al view of a portion of the anchor, Figure l;
Figure 4 is an elevation Al view of the anchor of Figure showing the same having been inserted into a bore hole, with the collar squeezed inwardly;
Figure 5 is an elevation Al view corresponding to Figure 4 but showing the reverse side, with the open-sided slot squeezed inwardly deforming the collar;
Figure 6 is an elevation Al view corresponding to Figure 4, after expansion of the collar;
Figure 7 is a partial section on elevation of an alternative embodiment;
I
Figure 8 is a sectiorlal view of a further alternate embodiment; arid Figure is a perspective illustration of a further embodiment.
As shown generally in Figure 1. an anchor according to the inventiorl will be seer to comprise a generally cylindrical shank 101 similar to the shank of a typical bolt. On an outer end indicated as 121 fastening means 14 are provided such as the male -threaded portion.
I This may carry a typical nut 16, and washer (not shown) such as are well known in the art. However any other threaded means may comprise the fastening means 14, such as a -threaded socket or the like such as is well known in the art.
The inner end ox the anchor is indicated generally as 18. It will be seen -to consist ox a reduced neck portion 20 owe cylindrical shape, and a progressively flaring -tapered portion 22. which glares out to the diameter of the shank portion 10. A right angular shoulder 24 is formed at the intersection between the reduced neck 20 and the shank 10.
Wedge means in the form of the collar indicated as 26 is provided on the reduced neck portion 20. The collar 26 is shown in more detail in Figure 2.
It will be seen to be a generally cylindrical shape and comprises a single band ox metal, -~yplcallY
being heavy gauge Haggard steel, with two ends 28-28 spaced apart. An open-ended axial slot 30 is formed in the collar 26, generally midway between ends 28 which thus places it more or less 180 degrees of arc ~7~3~7~
away from the ends 28. The slot 30 does not extend the full width owe the collar 26, and leaves a bridging portion 32 ox the collar 26.
Slot 30 defines at its open end a pair of sharp corners 34. The -two ends 28 similarly define a pair of sharp corners 36.
A pair of generally dome-shaped abutments 38-3~ are formed on opposite sides ox the collar 26.
Two such dome-shaped abutments are shown. It will however be appreciated that in a larger collar, on a larger diameter anchor three or more such dome-shaped members could be used if desired. The dome-shaped members are formed merely by pressing impressions or deformations in the metal, and the metal. is not in fact cut or severed or weakened at this point. Preferably, the depressions or domes 38 are formed in such a way that they are substantially midway between across the width of the collar 36, so that they leave marginal portions 40 of the collar 38 on either side (see Figure 7) which is free of deformation.
Collar 26 is of such a width that it extends from the tight angular shoulder 24, over the full extent of the reduced neck portion 20 and part way up the tapered portion 22. The transition between the reduced neck 20 and tapered portion 22 is shown as a phantom dotted line in Figures 3, 4, and 5.
The length of the collar 26 is such that it will not completely encircle the reduced neck portion 20, so that the two ends 28 define a gap between . 34 them. In this way the collar 26 makes a loose fit around the neck 20. In fact the collar 26 can be freely rotated around the neck 20, prior to insertion into a bore hole.
Figure 3 illustrates -this condition prior to insertion in the bore hole.
Egress 4, 5, and 6 indicate the operation of the collar after insertion in the bore hole.
In Figure I, the collar 26 is shown hazing been squeezed or compressed within the bore hole. This takes place by the reaction between the domes 38 and the sides of the bore hole, as the anchor is driven manually into the bore hole.
It will be noted that the bore hole maces a snug fit around the shank of the 10 at the anchor, and as shown in Figure 3 the diametrical spacing Hutton the outer surfaces of the domes 38 is greater than the diameter of the shank Lo Thus the dimensions of the bore hole are such as to apply considerable compressive force to the domes 38 and to actually cause an inward squeezing of collar 26. This inward squeezing will be seen in Figure 4 to have caused closure of the free ends 38. The free ends 28 are not always completely closed. They will usually he squeezed closer together than in the position shown in Figure 3.
Looking at the reverse side, in Figure 5, the squeezing action of the bore hole in this case causes a somewhat different action. The open end of the slot 30 has been squeezed inwardly or closed, whereas the bridging portion 32 of the collar has maintained the inward end of the slot 30 open.
Thus it will be seen -that the inner end of the collar, i.e., the end overlapping the taper 22, has been squeezed tighter than the outer end, i.e., the end which is s-till overlying the reduced neck 20.
It will also be observed that by this action, the two sharp points 34 at the open end of -the slot 30 and the two sharp points 36 defined by the two free ends 28 of the collar 26, have all been forced tightly into engagement with the tapered portion 22. In fact, these sharp corners and the inner edge of the collar will thus bite into the metal of the taper 22, forming a secure frictional engagement, which is effective to resist substantial rotative forces.
Similarly, the engagement between the domes 38 and the sides of -the bore hole is of a resilient nature such that the tighter the fit the better the grip between the collar and the bore hole. Thus the bore hole grips the collar, and the collar in turn tightly grips the shank. The anchor is thus held against rotation.
In order to develop the maximum holding power, tension is then applied to the outer end of the anchor 10. Typically this is done by simply tightening up the nut 16~ Alternatively t axial tension can be applied by means of a claw hammer or the like, which by means of leverage can pry the outer end of the anchor outwardly.
This will cause the tapered portion 22 to be forced progressively into the collar 26 which will thus cause expansion. The collar 26 is in turn held in position in the bore hole by means of the engagement between the domes 38 and the sides of the bore hole.
I
Thus the collar 26 is forcibly expanded into tight engagement within the sides of the bore hole, substantially as shown in Figure 6. Clearly the degree of expansion ox the collar 26 will depend upon the compressive strength of the material in which the bore hole is formed which may vary widely from one type of concrete or material to another.
Substantial pullout forces can be developed in this way which are found to be highly effective in practice, and which resist vibration loads, and provides a highly satisfactory form of fastening in the base material.
It is also found thaw such anchors are particularly convenient for workmen to install since they do not tend to become dismantled or come apart during handling, and are capable of withstanding rough usage and even considerable abuse and will still unction as designed.
Various modifications are possible. For example, as shown in Figure 7, the shank 10 can be provided with an internally threaded recess 50, which may receive a threaded rod or bolt or the like (not shown).
In order to assist in firmly setting an anchor of this type, an anchor setting device indicated gent orally as 52 is provided. This comprises a bolt 54, and a heavy gauge washer or bearing member I which. is threadedly engaged on the bolt 54.
The setting device 52 provides a convenient means by which the anchor 10 may first of all be inserted into the bore hole, and may then have tension I
applied to i-t to partially pull it out -thereby developing the maximum pullout forces.
This type of anchor is intended to be set so that -the outer end is flush with the surface of the receiving material or concrete. In order to do this, since a certain outward movement takes place during the setting of the anchor, i-t is necessary that the bore hole shall be drilled somewhat longer than the length of the anchor lo The anchor lo is then inserted so lo that it is in fact inserted with its outer end inwardly of the outer end of the bore hole. This is achieved by simply unthreading the bolt I partially from the recess or socket 50 (as shown in phantom). The bolt 5~1 can then simply be hammered thereby forcing the anchor lo inwardly in -the bore hole.
By means of a wrench, the nut 54 is then simply tightened up, and this applies the axial tension to the anchor lo which causes the expansion of -the collar as shown in Figure 6. With a very little practice, it is possible for workmen to insert and then tension the anchors Lucy that the outer end of the anchors lo come substantially flush to the surface of the receiving material.
This is particularly advantageous in con-struction of large commercial buildings, where it may be desirable to apply exterior finishes to the surface of the concrete after the insertion of the anchors lo If desired, the setting devices 52 can be let in position, to prevent the introduction of foreign ~3~7~
matter into the recesses 50 during the finishing process.
The setting devices 52 can then be removed, and the recesses 50 are then available for threading of any suitable attachment. Typically this will be a threaded rod such as is used for hanging appliances, ducts, water pipes, sprinkler systems and toe like.
Another modification is shown in Figure 3.
In certain eases much higher pullout forces are required from a Senegal anchor. In this case tile anchor lo may have a somewhat longer shank, which is provided with two tapered portions 22 and AYE, and two collars 26 and 26~.
To precut, an anchor having a double dollar and double taper of this type will be found to develop a higher pullout resistance -than an anchor having a single collar although in practice it is not quite equal to double the pullout resistance of a single collar.
A further modification is shown in FicJure 9 wherein an attachment means indicated generally as 60 I is provided on the outer end of the shank 10. In this ease the attachment means simply comprises a tongue portion 62 having a hole 64. Tupelo, this -type of anchor is used for hanging suspended ceilings, in which the ceiling grid is suspended on wire suspension means.
Iiaving described what is believed to be toe best mode by which the invention may be performed, it will be seen that the invention may be particularly derailed as follows;
An anchor compri.xin(3 a shank Wylie an inlay-end and an outer end, a reduced neck portion formed one inner end, a flaring expansion portion extending - , .. Jo .... . .
- - -I
from the reduced reck, engagement means on the outer end of such shank, a one-piece wedging collar arranged around the reduced neck portion on the inner end, and having an overlapping portion extending partially up the tapered portion, the collar being formed of a single strip of metal having two ends and a leading edge and a trailing edge, such collar being formed with said two ends arranged end to end spaced apart from one another defining an open gap, and such collar having, in an intermediate lo portion thereof, an axial slotted opening extending from said leading edge part way thrilling and defining one open end, the open end being directed towards said expansion portion of said anchor, at least two generally dome-shaped bosses formed in said collar, extending outwardly there-from, and defining a maximum spacing there between greater than the diameter of said chainlike of said anchor, said collar making a loose fit around said reduced neck portion, and being squeezable throned into a tight frictional engagement thereon with said overlapping portion of such collar extending tightly around such expansion portion, upon engagement of said domelike bosses within -the surface of a bore hole, whereby said shank is held tightly against rotation, said collar being expandable by said expansion portion upon outward axial movement of such shank, said collar -thereby wedging against the surfaces of such bore hole -to secure said anchor.
The foregoing is a description of a preferred embodiment of the invention which is given here by way of examples only. The invention is not to be taken as limited to any of the specific features as described, but comprehends all such variations thereof as come within the scope of the appended claims.
I
The invention relates to an anchor device for use in materials such as concrete, blocks, and certain types of stone.
Background of the Invention A well known form of anchor for concrete employs a shank having a tapered expansion portion in its inner end. An axially movable or wedge collar formed of two pieces of metal is arranged around the -tapered portion and can be expanded outwardly by applying tension along the axis of the anchor. The collar is then wedged outwardly against the concrete or masonry material by the tapered portion.
One form of such an anchor is shown in Canadian Patent No. 766,~93, issued to AGO. McCulloch on September 5, 1967.
One of the problems of that type of anchor was the tact that the collar was formed of two or more separate pieces, which were held in position initially by means of adhesive tape or the like. There was always the possibility for the adhesive tape to become dislodged or damaged, and the collars might simply fall off. When introducing the anchor into a bore hole, in other than ideal conditions, there was also a tendency for the collars to become loosened and lost.
A more serious disadvantage was the fact that the anchor is usually used with some form of threaded attachment means at its outer end. This may take the form of a male thread, or may take the form of a socket, these two being the most popular forms of this type of anchor.
In order therefore to apply the expanding tension along the axis of the anchor, it is necessary for something such as a nut, threaded rod or the like to be attached to the outer end of the anchor. However, in this type of anchor there was no structure to prevent rotation of the entire anchor.
If this occurred, then the threaded fastening device at its outer end could only be tightened up with the greatest difficulty.
An improved form of anchor is shown in Canadian Patents 899,669 issued -to R. Seetaram on May 9, 1972 and 953,958, issued to JO Seetaram on September 3, 1974.
In this type of anchor the wedge on the collar is formed of a single piece of metal, and the tapered expansion portion is formed with some form of collar engagement surfaces either in the form of a flattened portion, or a bed or button or groove. The collar also had outwardly extending tongues for engaging the sides of the hole in the concrete The collar was thus hold by the concrete against rotation. The collar in turn through its engagement with the surfaces on the tapered portion, held the shaft against rotation.
This device was a considerable improvement both in the fact that the collar was made of one piece of metal so that it could not become lost, and also because it was much easier to tighten up when a threaded fastening device was attached to the outer end.
However, it is difficult to manufacture the engagement surfaces and the collar to suitable tolerances in existing mass production techniques, and in practice : ' ~39L7~
either the tolerances become so slack that the engage-mint is not sufficiently secure, or alternatively the costs of production rise to the point where customers will not purchase the anchor.
An additional disadvantage of -this anchor in practice was found to be the fact that the tongues on the collar tended to become deformed as the anchor was driven into the hole in the concrete. As a result, they no longer had the same holding capacity, so that in certain circumstances it was still possible for the entire anchor to rotate.
For all of these reasons therefore it is clearly desirable to provide an anchor having a more secure form of engagement between the collar and the side walls of . the Holland also having a more secure Norm of engage-mint between the collar and the tapered portion of the shaft, so as -to positively resist rotation, and at the same time, being capable of being manufactured by simpler mass production techniques, where critical tolerances do not require to be held to the same degree.
Brief Summary of the Invention With a view to providing the foregoing features in a simplified form of anchor, the invention comprises an anchor having a shank with an inner end and an outer end, a reduced neck portion formed on the inner end, and a tapering portion extending from thy reduced neck, and : having engagement means on the outer end, and a one-piece expansion collar arranged around the reduced neck portion on the inner end, and extending partially up the tapered portion, the collar being formed of a single strip of I
metal having two ends, such collar being formed with said two ends in end a butting relation, and briny spaced apart from one another defining an open gap, and such collar having, in an intermediate portion thereof, an axial slot extending part way there through and defining one open end, the open end being directed towards said tapered portion of said anchor, and there being at least two generally dome shaped bosses formed in said collar, extending outwardly therefrom, and defining a maximum spacing there between greater than the diameter of the shaft shank of such anchor, said collar making a loose fit around said reduced neck portion, and being squeezable there around into a tight frictional engagement thereon with a short portion of such collar extending tightly around portion of such tapered portion, upon engagement of said domelike bosses within the sun-faces of a bore hole.
More particularly, the invention provides such an anchor wherein the two ends of such collar, and the open-ended slot formed in such collar, define at least fur pointed areas overlying part of such tapered portion, such pointed areas being squeezable together upon forcing ' of said anchor into a bore hole, and said pointed areas being thereby forced into engagement with the tapered portion of said shaft adjacent said reduced neck portion, thereby providing a good frictional engagement between said collar and said shaft, whereby to resist rotation of said anchor.
More particularly, the invention provides an anchor having the foregoing advantages, wherein the open-ended slot in said collar defines a predetermined spacing therein, such that when the collar is squeezed I
together around the reduced neck and the tapered portion of the shank, the area of the collar adjacent to the open-ended slot is squeezed inwardly.
The various features of novelty which kirk-Tories the invention are pointed out with particularity in the claims annexed to and forming a part ox this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are ` illustrated and described preferred embodiments of the oven lion .
In the Drawings .
Figure 1 is a perspective illustration of an anchor according to the invention;
Figure 2 is a perspective illustration of the collar of Figure 1 shown in isolation;
Figure 3 is an elevation Al view of a portion of the anchor, Figure l;
Figure 4 is an elevation Al view of the anchor of Figure showing the same having been inserted into a bore hole, with the collar squeezed inwardly;
Figure 5 is an elevation Al view corresponding to Figure 4 but showing the reverse side, with the open-sided slot squeezed inwardly deforming the collar;
Figure 6 is an elevation Al view corresponding to Figure 4, after expansion of the collar;
Figure 7 is a partial section on elevation of an alternative embodiment;
I
Figure 8 is a sectiorlal view of a further alternate embodiment; arid Figure is a perspective illustration of a further embodiment.
As shown generally in Figure 1. an anchor according to the inventiorl will be seer to comprise a generally cylindrical shank 101 similar to the shank of a typical bolt. On an outer end indicated as 121 fastening means 14 are provided such as the male -threaded portion.
I This may carry a typical nut 16, and washer (not shown) such as are well known in the art. However any other threaded means may comprise the fastening means 14, such as a -threaded socket or the like such as is well known in the art.
The inner end ox the anchor is indicated generally as 18. It will be seen -to consist ox a reduced neck portion 20 owe cylindrical shape, and a progressively flaring -tapered portion 22. which glares out to the diameter of the shank portion 10. A right angular shoulder 24 is formed at the intersection between the reduced neck 20 and the shank 10.
Wedge means in the form of the collar indicated as 26 is provided on the reduced neck portion 20. The collar 26 is shown in more detail in Figure 2.
It will be seen to be a generally cylindrical shape and comprises a single band ox metal, -~yplcallY
being heavy gauge Haggard steel, with two ends 28-28 spaced apart. An open-ended axial slot 30 is formed in the collar 26, generally midway between ends 28 which thus places it more or less 180 degrees of arc ~7~3~7~
away from the ends 28. The slot 30 does not extend the full width owe the collar 26, and leaves a bridging portion 32 ox the collar 26.
Slot 30 defines at its open end a pair of sharp corners 34. The -two ends 28 similarly define a pair of sharp corners 36.
A pair of generally dome-shaped abutments 38-3~ are formed on opposite sides ox the collar 26.
Two such dome-shaped abutments are shown. It will however be appreciated that in a larger collar, on a larger diameter anchor three or more such dome-shaped members could be used if desired. The dome-shaped members are formed merely by pressing impressions or deformations in the metal, and the metal. is not in fact cut or severed or weakened at this point. Preferably, the depressions or domes 38 are formed in such a way that they are substantially midway between across the width of the collar 36, so that they leave marginal portions 40 of the collar 38 on either side (see Figure 7) which is free of deformation.
Collar 26 is of such a width that it extends from the tight angular shoulder 24, over the full extent of the reduced neck portion 20 and part way up the tapered portion 22. The transition between the reduced neck 20 and tapered portion 22 is shown as a phantom dotted line in Figures 3, 4, and 5.
The length of the collar 26 is such that it will not completely encircle the reduced neck portion 20, so that the two ends 28 define a gap between . 34 them. In this way the collar 26 makes a loose fit around the neck 20. In fact the collar 26 can be freely rotated around the neck 20, prior to insertion into a bore hole.
Figure 3 illustrates -this condition prior to insertion in the bore hole.
Egress 4, 5, and 6 indicate the operation of the collar after insertion in the bore hole.
In Figure I, the collar 26 is shown hazing been squeezed or compressed within the bore hole. This takes place by the reaction between the domes 38 and the sides of the bore hole, as the anchor is driven manually into the bore hole.
It will be noted that the bore hole maces a snug fit around the shank of the 10 at the anchor, and as shown in Figure 3 the diametrical spacing Hutton the outer surfaces of the domes 38 is greater than the diameter of the shank Lo Thus the dimensions of the bore hole are such as to apply considerable compressive force to the domes 38 and to actually cause an inward squeezing of collar 26. This inward squeezing will be seen in Figure 4 to have caused closure of the free ends 38. The free ends 28 are not always completely closed. They will usually he squeezed closer together than in the position shown in Figure 3.
Looking at the reverse side, in Figure 5, the squeezing action of the bore hole in this case causes a somewhat different action. The open end of the slot 30 has been squeezed inwardly or closed, whereas the bridging portion 32 of the collar has maintained the inward end of the slot 30 open.
Thus it will be seen -that the inner end of the collar, i.e., the end overlapping the taper 22, has been squeezed tighter than the outer end, i.e., the end which is s-till overlying the reduced neck 20.
It will also be observed that by this action, the two sharp points 34 at the open end of -the slot 30 and the two sharp points 36 defined by the two free ends 28 of the collar 26, have all been forced tightly into engagement with the tapered portion 22. In fact, these sharp corners and the inner edge of the collar will thus bite into the metal of the taper 22, forming a secure frictional engagement, which is effective to resist substantial rotative forces.
Similarly, the engagement between the domes 38 and the sides of -the bore hole is of a resilient nature such that the tighter the fit the better the grip between the collar and the bore hole. Thus the bore hole grips the collar, and the collar in turn tightly grips the shank. The anchor is thus held against rotation.
In order to develop the maximum holding power, tension is then applied to the outer end of the anchor 10. Typically this is done by simply tightening up the nut 16~ Alternatively t axial tension can be applied by means of a claw hammer or the like, which by means of leverage can pry the outer end of the anchor outwardly.
This will cause the tapered portion 22 to be forced progressively into the collar 26 which will thus cause expansion. The collar 26 is in turn held in position in the bore hole by means of the engagement between the domes 38 and the sides of the bore hole.
I
Thus the collar 26 is forcibly expanded into tight engagement within the sides of the bore hole, substantially as shown in Figure 6. Clearly the degree of expansion ox the collar 26 will depend upon the compressive strength of the material in which the bore hole is formed which may vary widely from one type of concrete or material to another.
Substantial pullout forces can be developed in this way which are found to be highly effective in practice, and which resist vibration loads, and provides a highly satisfactory form of fastening in the base material.
It is also found thaw such anchors are particularly convenient for workmen to install since they do not tend to become dismantled or come apart during handling, and are capable of withstanding rough usage and even considerable abuse and will still unction as designed.
Various modifications are possible. For example, as shown in Figure 7, the shank 10 can be provided with an internally threaded recess 50, which may receive a threaded rod or bolt or the like (not shown).
In order to assist in firmly setting an anchor of this type, an anchor setting device indicated gent orally as 52 is provided. This comprises a bolt 54, and a heavy gauge washer or bearing member I which. is threadedly engaged on the bolt 54.
The setting device 52 provides a convenient means by which the anchor 10 may first of all be inserted into the bore hole, and may then have tension I
applied to i-t to partially pull it out -thereby developing the maximum pullout forces.
This type of anchor is intended to be set so that -the outer end is flush with the surface of the receiving material or concrete. In order to do this, since a certain outward movement takes place during the setting of the anchor, i-t is necessary that the bore hole shall be drilled somewhat longer than the length of the anchor lo The anchor lo is then inserted so lo that it is in fact inserted with its outer end inwardly of the outer end of the bore hole. This is achieved by simply unthreading the bolt I partially from the recess or socket 50 (as shown in phantom). The bolt 5~1 can then simply be hammered thereby forcing the anchor lo inwardly in -the bore hole.
By means of a wrench, the nut 54 is then simply tightened up, and this applies the axial tension to the anchor lo which causes the expansion of -the collar as shown in Figure 6. With a very little practice, it is possible for workmen to insert and then tension the anchors Lucy that the outer end of the anchors lo come substantially flush to the surface of the receiving material.
This is particularly advantageous in con-struction of large commercial buildings, where it may be desirable to apply exterior finishes to the surface of the concrete after the insertion of the anchors lo If desired, the setting devices 52 can be let in position, to prevent the introduction of foreign ~3~7~
matter into the recesses 50 during the finishing process.
The setting devices 52 can then be removed, and the recesses 50 are then available for threading of any suitable attachment. Typically this will be a threaded rod such as is used for hanging appliances, ducts, water pipes, sprinkler systems and toe like.
Another modification is shown in Figure 3.
In certain eases much higher pullout forces are required from a Senegal anchor. In this case tile anchor lo may have a somewhat longer shank, which is provided with two tapered portions 22 and AYE, and two collars 26 and 26~.
To precut, an anchor having a double dollar and double taper of this type will be found to develop a higher pullout resistance -than an anchor having a single collar although in practice it is not quite equal to double the pullout resistance of a single collar.
A further modification is shown in FicJure 9 wherein an attachment means indicated generally as 60 I is provided on the outer end of the shank 10. In this ease the attachment means simply comprises a tongue portion 62 having a hole 64. Tupelo, this -type of anchor is used for hanging suspended ceilings, in which the ceiling grid is suspended on wire suspension means.
Iiaving described what is believed to be toe best mode by which the invention may be performed, it will be seen that the invention may be particularly derailed as follows;
An anchor compri.xin(3 a shank Wylie an inlay-end and an outer end, a reduced neck portion formed one inner end, a flaring expansion portion extending - , .. Jo .... . .
- - -I
from the reduced reck, engagement means on the outer end of such shank, a one-piece wedging collar arranged around the reduced neck portion on the inner end, and having an overlapping portion extending partially up the tapered portion, the collar being formed of a single strip of metal having two ends and a leading edge and a trailing edge, such collar being formed with said two ends arranged end to end spaced apart from one another defining an open gap, and such collar having, in an intermediate lo portion thereof, an axial slotted opening extending from said leading edge part way thrilling and defining one open end, the open end being directed towards said expansion portion of said anchor, at least two generally dome-shaped bosses formed in said collar, extending outwardly there-from, and defining a maximum spacing there between greater than the diameter of said chainlike of said anchor, said collar making a loose fit around said reduced neck portion, and being squeezable throned into a tight frictional engagement thereon with said overlapping portion of such collar extending tightly around such expansion portion, upon engagement of said domelike bosses within -the surface of a bore hole, whereby said shank is held tightly against rotation, said collar being expandable by said expansion portion upon outward axial movement of such shank, said collar -thereby wedging against the surfaces of such bore hole -to secure said anchor.
The foregoing is a description of a preferred embodiment of the invention which is given here by way of examples only. The invention is not to be taken as limited to any of the specific features as described, but comprehends all such variations thereof as come within the scope of the appended claims.
I
Claims (5)
1. An anchor comprising:
a shank with an inner end and an outer end and a central axis, said shank having an intermediate reduced diameter neck portion of predetermined length;
an expansion portion flaring from said reduced neck portion towards said inner end;
engagement means on the outer end of said shank;
a one-piece wedging collar loosely encircling said reduced neck portion having a length greater than said predetermined length of said reduced neck portion and extending partially up said expansion portion, said collar being formed of a single strip of metal having two side edges, and a leading end edge and a trailing end edge, said collar being formed with said two side edges arranged spaced apart from one another defining an open gap;
an axial slot formed in said collar intermediate said two side edges of said collar, said slot extending part way therealong and defining an open forward end at said leading edge and a blind rear end adjacent said trailng end edge of said collar, said open forward end being directed towards said expansion portion and defining corners on opposite sides of said open forward end;
a bridge portion of said collar located between said rear end of said slot, and said trailing end edge of said collar, said axial slot being open from said bridge portion to said leading end edge of said collar;
at least two generally dome-shaped bosses formed in said collar on opposite sides of said axial slot located between said bridge portion and said leading end edge of said collar, said bosses extending outwardly therefrom, and defining a maximum spacing therebetween greater than the diameter of said shank of said anchor;
said collar making a loose fit around said reduced neck portion and a portion of said expansion portion, and said leading end edge of said collar being squeezable around said expansion portion into a tight frictional engagement thereon with a portion of said collar extending tightly around said expansion portion, upon engagement of said dome-shaped bosses within the surface of a bore hole, whereby said axial slot is closed at its open forward end, while said bridge portion holds said axial slot against closing at its blind end thereby driving said corners into said expansion portion whereby said shank is held tightly against rotation, said collar being expandable by said expansion portion upon outward axial movement of said shank, said collar thereby wedging against the surfaces of said bore hole to secure said anchor.
a shank with an inner end and an outer end and a central axis, said shank having an intermediate reduced diameter neck portion of predetermined length;
an expansion portion flaring from said reduced neck portion towards said inner end;
engagement means on the outer end of said shank;
a one-piece wedging collar loosely encircling said reduced neck portion having a length greater than said predetermined length of said reduced neck portion and extending partially up said expansion portion, said collar being formed of a single strip of metal having two side edges, and a leading end edge and a trailing end edge, said collar being formed with said two side edges arranged spaced apart from one another defining an open gap;
an axial slot formed in said collar intermediate said two side edges of said collar, said slot extending part way therealong and defining an open forward end at said leading edge and a blind rear end adjacent said trailng end edge of said collar, said open forward end being directed towards said expansion portion and defining corners on opposite sides of said open forward end;
a bridge portion of said collar located between said rear end of said slot, and said trailing end edge of said collar, said axial slot being open from said bridge portion to said leading end edge of said collar;
at least two generally dome-shaped bosses formed in said collar on opposite sides of said axial slot located between said bridge portion and said leading end edge of said collar, said bosses extending outwardly therefrom, and defining a maximum spacing therebetween greater than the diameter of said shank of said anchor;
said collar making a loose fit around said reduced neck portion and a portion of said expansion portion, and said leading end edge of said collar being squeezable around said expansion portion into a tight frictional engagement thereon with a portion of said collar extending tightly around said expansion portion, upon engagement of said dome-shaped bosses within the surface of a bore hole, whereby said axial slot is closed at its open forward end, while said bridge portion holds said axial slot against closing at its blind end thereby driving said corners into said expansion portion whereby said shank is held tightly against rotation, said collar being expandable by said expansion portion upon outward axial movement of said shank, said collar thereby wedging against the surfaces of said bore hole to secure said anchor.
2. An anchor as claimed in Claim 1 wherein said two side edges of said collar, and said open end of said slot formed in said collar, define at least four pointed corners overlying part of said expansion portion, said pointed corners being squeezable together upon forcing of said anchor into a bore hole, and said pointed corners being thereby forced into said expansion portion adjacent said reduced neck portion, thereby providing a good frictional engagement between said collar and said shank, whereby to resist rotation of said anchor.
3. An anchor as claimed in Claim 2 wherein said dome-shaped bosses are formed on opposite sides of said collar, in opposition to one another around the circumference thereof, whereby to engage opposite sides of a bore hole in a work piece.
4. An anchor as claimed in Claim 1 wherein said shank has a predetermined uniform outer diameter along its length from its outer end to said reduced neck portion, and wherein said engagement means comprises a female threaded bore in said outer end axially of said shank, for reception of a threaded member therein, and including an anchor tensioning bolt threadedly engaging said female threaded recess, and an oversized washer on said bolt, whereby said anchor may be inserted completely into a bore hole, and thereafter tension may be applied along the axis of said anchor by tigthening up said tensioning bolt, whereby to procure expansion of said collar by said expansion portion, such tensioning bolt being thereafter removed.
5. An anchor as claimed in Claim 1 including a second reduced neck portion extending axially from said flaring expansion portion, and including a second flaring expansion portion extending axially from said second reduced neck portion, and including a second wedging collar arranged around said second reduced neck portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000419510A CA1234711A (en) | 1983-01-14 | 1983-01-14 | Stud anchor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000419510A CA1234711A (en) | 1983-01-14 | 1983-01-14 | Stud anchor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1234711A true CA1234711A (en) | 1988-04-05 |
Family
ID=4124341
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000419510A Expired CA1234711A (en) | 1983-01-14 | 1983-01-14 | Stud anchor |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1234711A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996011343A1 (en) * | 1994-10-05 | 1996-04-18 | Upat Gmbh & Co. | Expanding anchor device |
| EP2048381A3 (en) * | 2007-10-12 | 2010-04-28 | HILTI Aktiengesellschaft | Fastening element |
| EP2243970A1 (en) * | 2009-04-22 | 2010-10-27 | Stanley Kaplan | Double collar wedge anchor |
-
1983
- 1983-01-14 CA CA000419510A patent/CA1234711A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996011343A1 (en) * | 1994-10-05 | 1996-04-18 | Upat Gmbh & Co. | Expanding anchor device |
| EP2048381A3 (en) * | 2007-10-12 | 2010-04-28 | HILTI Aktiengesellschaft | Fastening element |
| EP2243970A1 (en) * | 2009-04-22 | 2010-10-27 | Stanley Kaplan | Double collar wedge anchor |
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| MKEX | Expiry |