CA1221258A - Blind anchor - Google Patents
Blind anchorInfo
- Publication number
- CA1221258A CA1221258A CA000428377A CA428377A CA1221258A CA 1221258 A CA1221258 A CA 1221258A CA 000428377 A CA000428377 A CA 000428377A CA 428377 A CA428377 A CA 428377A CA 1221258 A CA1221258 A CA 1221258A
- Authority
- CA
- Canada
- Prior art keywords
- anchor
- head
- mandrel
- flange
- extending
- 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
Landscapes
- Dowels (AREA)
Abstract
Abstract of the Disclosure A blind anchor having an elongated body defining a cylindrical inner surface made of a deformable material and with a plurality of axially extending slits extending to one end of the body. A mandrel has a stem extending through the body and a head with a diameter greater than the inner diameter of the body. When the mandrel is pulled, the head enters the body causing it to expand so as to bite into the margins of a hole in which it is mounted or spread behind the hole if the body length exceeds the hole length.
Description
2~S8 I N TROD UCT IO N
~ .
This invention relates to blind fasteners and more particularly comprises a mandrel-type expandable anchor which may be mounted in masonry, plaster, wood, metal, etc. The anchor may be set in a wall of any thickness.
Mandrel-type fasteners are very well known. Most of them, howeverl are only capable of being secured in a hole through which it fully extends so that it may set like a rivet behind the hole. The mandrel-type fastener of the present invention is capable of being set in a hole in the manner of a conventional rivet if it exceeds the hole length or it may be anchored in a hole which is longer than the anchor itself. Thu~, the anchor has a more universal application than other mandrel-type fasteners now available.
In accordance with the present invention, the anchor is composed of a body and a mandrel. The body is generally ; cylindrical in shape and is provided with a flange at its front end, which serves as its head when the anchor is set in a hole. A number of slits are provided in the body which extend axially to the rear end of the body but terminate ; 20 short of the head at the front end. The mandrel carries a head which extends out the rear of the body while the mandrel stem extends through the body and out beyond the head so that ~; it may be engaged by a pulling tool for setting the anchor.Preferably the body of the anchor has a number of annular barbs on its outer surface which can bite into the wall of the hole in which the anchor is to be set. By pulling the mandrel, the mandrel head enters the body which is allowed to ~xpand readily because of the slits, until the tension on the mandrel causes it to break just forward of the mandrel head.
The anchor may be used to hang or otherwise secure any type ~2~Z~i8 of device to the wall or o1:her structure to which it is connected.
The invention will be better understood and appreciated from the following detailed description read in connection with the accompanying drawings in which:
BRIEF FIGURE DESCRIPTION
FIG. 1 is a side view of a blind anchor constructed in accordance with this invention;
FIG. 2 is a longitudinal cross-sectional view of the anchor shown in FIG. l;
FIG. 3 is a cross sectional view of the anchor taken along the section line 3-3 in FIG. iY;
FIG. 4 is a longitudinal cross-sectional view howing the anchor set in a masonry wall;
FIG. 5 is a fragmentary cross-sectional view of the body of another embodiment of anchor constructed in acccrdance with this invention.
DETAILED DESCRIPTION
The anchor shown in FIGS. 1-4 includes a body l0 and mandrel 12. The body may be made of metal, plastic or other material and should be capable of deforming without fracturing or shattering. In smaller sizes and lighter applications particularly, the body may be made inexpensively of a plastic material. Typically, the body may be approximately l inch in length and its diameter may vary from approximately 1/8 inch to 1~2 inchv again depending upon its application. The body 10 is provided with a flange or head 14 at its front end having a diameter appreciably larger than the diameter of the main part of the body so as to define a 3L~2Z~2~3 stop to limit the depth of penetration of the body in the hole in which it i5 to be mounted. The head may be round, polygon, or other shape, and it may be countersunk, flat, or any other configuration determined by the particular application~
In the embodiment of FIGS. 1-4, three longitudinally extending slits 1~ are provided in the body 10 but a greater or lesser number may be employed. The slits 16 extend to the rear end 18 of the body and terminate at the front end short of ~he flange 14. The slits 16 extend completely through the walls so as to enable the body to deflect radially outwardly when internal forces are applied to it. A plurality of annular barbs 20 extend about the body 10 but are interrupted by the slits 16. The barbs 20 are provided to bite into the walls of the hole in which the anchor is mounted Mandrel 12 which may be made of aluminum, steel or other relatively hard and strong material, includes an elongated stem 22, and on the rear end of the stem is a head 24. The front end of the mandrel stem 22 extends outwardly beyond the ; flange 14 of the body while the head 24 of the mandrel extends beyond its rear end 18. The diameter of the stem 22 is slightly less than the inner diameter of the body 10 so as not to interfere with the pulling of the mandrel through the body when the anchor is set. The head 24 merges smoothly into the stem so that the diameter of its smaller end is essentially equal to the stem diameter. The head diameter increases in a rearward direction away from the body and, therefore, the diameter at its outer end i~ appreciably larger than the inner diameter of the body but no greater than the outer diameter of the body. The rear end 18 of the body at the head of the mandrel may be chamfered as shown in FIG. 2 to lead the head 24 into the body when the anchor is .
i8 set as described below. In the embodiment shown, a few annular barbs 26 are provided on the head, but these are not essential to the operation of the fastener. m e barbs may serve to assist in holding the head 24 in the body when the anchor is set, as is described more fully below.
In FIG. 2 it will be noted that the diameter of the stem 22 immediately adjacent the head 24 is reduced by a groove or notch 30 which may extend about the stem~ The groove 30 provides a weakened section in the mandrel which will cause the mandrel to break at that point when a sufficient tension force is applied to it.
A typical application of the anchor is shown in FIG. 4.
In that figure a masonry wall 32 is shown provided with a drilled hole 34 which exceeds the length of the anchor body m e anchor is shown in that figure to support a hook-like member 36 which is exemplary of the type of device which may be secured to the wall 32 by the anchorO m e member 36 is provided with a hole 38 which just exceeds the outer diameter of the body 10 but which is smaller than the diameter of the flange 14. To mount the member 36 as shown, the body 10 is inserted through the hole 38 in the member 36 and then into the hole 34 bored in the masonry. The anchor including the mandrel 12 and body 10 are in the configuration shown in FIG. 2 when the anchor is inserted in hole 34. With the use of a tool for setting blind fasteners, the portion of the stem 22 of the mandrel which extends beyond the flange 14 is engaged and pulled to the right as viewed in FIG. 4 so as to cause the body 10 to spread as the head 2~ of the mandrel is pulled inside the body. The slits 16 enable the body 10 to expand under the influence of the head 24 being pulled into it. As the body spreads, the circular barbs 20 bite ., s~
into the margins of the hole 34. The head 24 continues to move inside the body 10 until the stem of the mandrel fractures at the groove 30~ When that occurs, the mandrel stem is pulled from the body and the head 24 is left in place as shown~ The compressible nature of the masonry material in wall 32 allows the body to expand as shown in FIG. 4. It will be appreciated that with the body expanded in that fashion, and with the head 24 in place in the body~ the anchor is ~ecure, and the member 36 will be retained on the wall. In FIG. 4 the open end of the body through the head or flange 14 is shown filled by a plug 40 which will prevent foreign material of any kind from entering the wall. The plug 40 is, of course, not essential to the operation of the anchor but it or some form of cap to close the body may be desirable for functional or aesthetic reasons.
While the anchor shown in FIG. 4 is permanently in place, it will be appreciated that the anchor may be removed if the head 24 is punched out the rear of the body. If the head 24 with the aid of a nail or other projection i5 driven rearwardly out of body 10, the deformable character of the body will enable it to be pulled from hole 34 in the masonry wall with an appropriate tool. The slits 16 in the body will allow the body to collapse to a diameter even smaller than its orignal diameter in the absence of the mandrel or other implement in the body interior.
While in the foregoing description the anchor is described as being set in a hole which exceeds the length of the anchor body, it will be appreciated that the same anchor may be used in a wall whose thickness is less than the body length. For that purpose, broken line S0 is provided in FIGo 4 to suggest that the depth of wall 32 is limited to the z~
plane represented by line 50. In that instance, when the body 10 is set in the hole drilled in the wal~, the rear end of the anchor extends out beyond the rear surface 50 of the wall. Nevertheless, by pulling the head 24 of the mandrel into the body in the manner shown in FIG. 4, the body will expand behind the rear surface 50, and when the mandrel breaks at groove 30, the anchor will serve as a blind rivet to support the member 36 on the front surface of the wall.
Thus it will be appreciated that the anchor may be used in walls having an infinite range of thicknesses . The slits allow the body to be spread to a point very close to the flange 14, and the manner in which the body spreads under the influence of the mandrel head 24 will be determined by ~he size and material of the wall in which it is set.
In FIG. 5 a modification of the anchor body is suggested. In the embodiment of FIGS. 1-4 the slits 16 extend completely through the body wall and essentially form the body into a plurality of parallel leaves that extend rearwardly from the head end of the body~ It may be desirable in certai.n applications, such as when the body is molded of plastic, to leave a very thin portion of the wall at the slit in tact to give the body greater integrity than it would otherwise be afforded. In this embodiment the slit 16a is shown to extend through the barb 20a and most of the body wall cross-section, but it terminates just short of the inner surface 60. Alternatively, the slit may terminate just short of the outer surface or the outer margin of the barbs.
As yet another alternative~ the slits could extend completely through the body but terminate just short of the rear end 18~ A great number of different arrangements may be used, all of which would allow the slits to open f~lly when the mandrel head is drawn i~ ~ ~e ~ody but which would hold the body's shape when the mandrel is in place but before it is drawn into it. That is, the head of the mandrel would fracture the slits to allow the body to expand as the anchor is set.
Having described this invention in detail, those skilled in the art will appreciate that numerous modifications may be made thereof without departing from its spirit. Therefore, it is not intended to limit the breadth of this invention to the single embodiment illustrated and described. Rather, it is intended that the scope of this invention be determined by the appended claims and their equivalents.
What is claimed is:
'
~ .
This invention relates to blind fasteners and more particularly comprises a mandrel-type expandable anchor which may be mounted in masonry, plaster, wood, metal, etc. The anchor may be set in a wall of any thickness.
Mandrel-type fasteners are very well known. Most of them, howeverl are only capable of being secured in a hole through which it fully extends so that it may set like a rivet behind the hole. The mandrel-type fastener of the present invention is capable of being set in a hole in the manner of a conventional rivet if it exceeds the hole length or it may be anchored in a hole which is longer than the anchor itself. Thu~, the anchor has a more universal application than other mandrel-type fasteners now available.
In accordance with the present invention, the anchor is composed of a body and a mandrel. The body is generally ; cylindrical in shape and is provided with a flange at its front end, which serves as its head when the anchor is set in a hole. A number of slits are provided in the body which extend axially to the rear end of the body but terminate ; 20 short of the head at the front end. The mandrel carries a head which extends out the rear of the body while the mandrel stem extends through the body and out beyond the head so that ~; it may be engaged by a pulling tool for setting the anchor.Preferably the body of the anchor has a number of annular barbs on its outer surface which can bite into the wall of the hole in which the anchor is to be set. By pulling the mandrel, the mandrel head enters the body which is allowed to ~xpand readily because of the slits, until the tension on the mandrel causes it to break just forward of the mandrel head.
The anchor may be used to hang or otherwise secure any type ~2~Z~i8 of device to the wall or o1:her structure to which it is connected.
The invention will be better understood and appreciated from the following detailed description read in connection with the accompanying drawings in which:
BRIEF FIGURE DESCRIPTION
FIG. 1 is a side view of a blind anchor constructed in accordance with this invention;
FIG. 2 is a longitudinal cross-sectional view of the anchor shown in FIG. l;
FIG. 3 is a cross sectional view of the anchor taken along the section line 3-3 in FIG. iY;
FIG. 4 is a longitudinal cross-sectional view howing the anchor set in a masonry wall;
FIG. 5 is a fragmentary cross-sectional view of the body of another embodiment of anchor constructed in acccrdance with this invention.
DETAILED DESCRIPTION
The anchor shown in FIGS. 1-4 includes a body l0 and mandrel 12. The body may be made of metal, plastic or other material and should be capable of deforming without fracturing or shattering. In smaller sizes and lighter applications particularly, the body may be made inexpensively of a plastic material. Typically, the body may be approximately l inch in length and its diameter may vary from approximately 1/8 inch to 1~2 inchv again depending upon its application. The body 10 is provided with a flange or head 14 at its front end having a diameter appreciably larger than the diameter of the main part of the body so as to define a 3L~2Z~2~3 stop to limit the depth of penetration of the body in the hole in which it i5 to be mounted. The head may be round, polygon, or other shape, and it may be countersunk, flat, or any other configuration determined by the particular application~
In the embodiment of FIGS. 1-4, three longitudinally extending slits 1~ are provided in the body 10 but a greater or lesser number may be employed. The slits 16 extend to the rear end 18 of the body and terminate at the front end short of ~he flange 14. The slits 16 extend completely through the walls so as to enable the body to deflect radially outwardly when internal forces are applied to it. A plurality of annular barbs 20 extend about the body 10 but are interrupted by the slits 16. The barbs 20 are provided to bite into the walls of the hole in which the anchor is mounted Mandrel 12 which may be made of aluminum, steel or other relatively hard and strong material, includes an elongated stem 22, and on the rear end of the stem is a head 24. The front end of the mandrel stem 22 extends outwardly beyond the ; flange 14 of the body while the head 24 of the mandrel extends beyond its rear end 18. The diameter of the stem 22 is slightly less than the inner diameter of the body 10 so as not to interfere with the pulling of the mandrel through the body when the anchor is set. The head 24 merges smoothly into the stem so that the diameter of its smaller end is essentially equal to the stem diameter. The head diameter increases in a rearward direction away from the body and, therefore, the diameter at its outer end i~ appreciably larger than the inner diameter of the body but no greater than the outer diameter of the body. The rear end 18 of the body at the head of the mandrel may be chamfered as shown in FIG. 2 to lead the head 24 into the body when the anchor is .
i8 set as described below. In the embodiment shown, a few annular barbs 26 are provided on the head, but these are not essential to the operation of the fastener. m e barbs may serve to assist in holding the head 24 in the body when the anchor is set, as is described more fully below.
In FIG. 2 it will be noted that the diameter of the stem 22 immediately adjacent the head 24 is reduced by a groove or notch 30 which may extend about the stem~ The groove 30 provides a weakened section in the mandrel which will cause the mandrel to break at that point when a sufficient tension force is applied to it.
A typical application of the anchor is shown in FIG. 4.
In that figure a masonry wall 32 is shown provided with a drilled hole 34 which exceeds the length of the anchor body m e anchor is shown in that figure to support a hook-like member 36 which is exemplary of the type of device which may be secured to the wall 32 by the anchorO m e member 36 is provided with a hole 38 which just exceeds the outer diameter of the body 10 but which is smaller than the diameter of the flange 14. To mount the member 36 as shown, the body 10 is inserted through the hole 38 in the member 36 and then into the hole 34 bored in the masonry. The anchor including the mandrel 12 and body 10 are in the configuration shown in FIG. 2 when the anchor is inserted in hole 34. With the use of a tool for setting blind fasteners, the portion of the stem 22 of the mandrel which extends beyond the flange 14 is engaged and pulled to the right as viewed in FIG. 4 so as to cause the body 10 to spread as the head 2~ of the mandrel is pulled inside the body. The slits 16 enable the body 10 to expand under the influence of the head 24 being pulled into it. As the body spreads, the circular barbs 20 bite ., s~
into the margins of the hole 34. The head 24 continues to move inside the body 10 until the stem of the mandrel fractures at the groove 30~ When that occurs, the mandrel stem is pulled from the body and the head 24 is left in place as shown~ The compressible nature of the masonry material in wall 32 allows the body to expand as shown in FIG. 4. It will be appreciated that with the body expanded in that fashion, and with the head 24 in place in the body~ the anchor is ~ecure, and the member 36 will be retained on the wall. In FIG. 4 the open end of the body through the head or flange 14 is shown filled by a plug 40 which will prevent foreign material of any kind from entering the wall. The plug 40 is, of course, not essential to the operation of the anchor but it or some form of cap to close the body may be desirable for functional or aesthetic reasons.
While the anchor shown in FIG. 4 is permanently in place, it will be appreciated that the anchor may be removed if the head 24 is punched out the rear of the body. If the head 24 with the aid of a nail or other projection i5 driven rearwardly out of body 10, the deformable character of the body will enable it to be pulled from hole 34 in the masonry wall with an appropriate tool. The slits 16 in the body will allow the body to collapse to a diameter even smaller than its orignal diameter in the absence of the mandrel or other implement in the body interior.
While in the foregoing description the anchor is described as being set in a hole which exceeds the length of the anchor body, it will be appreciated that the same anchor may be used in a wall whose thickness is less than the body length. For that purpose, broken line S0 is provided in FIGo 4 to suggest that the depth of wall 32 is limited to the z~
plane represented by line 50. In that instance, when the body 10 is set in the hole drilled in the wal~, the rear end of the anchor extends out beyond the rear surface 50 of the wall. Nevertheless, by pulling the head 24 of the mandrel into the body in the manner shown in FIG. 4, the body will expand behind the rear surface 50, and when the mandrel breaks at groove 30, the anchor will serve as a blind rivet to support the member 36 on the front surface of the wall.
Thus it will be appreciated that the anchor may be used in walls having an infinite range of thicknesses . The slits allow the body to be spread to a point very close to the flange 14, and the manner in which the body spreads under the influence of the mandrel head 24 will be determined by ~he size and material of the wall in which it is set.
In FIG. 5 a modification of the anchor body is suggested. In the embodiment of FIGS. 1-4 the slits 16 extend completely through the body wall and essentially form the body into a plurality of parallel leaves that extend rearwardly from the head end of the body~ It may be desirable in certai.n applications, such as when the body is molded of plastic, to leave a very thin portion of the wall at the slit in tact to give the body greater integrity than it would otherwise be afforded. In this embodiment the slit 16a is shown to extend through the barb 20a and most of the body wall cross-section, but it terminates just short of the inner surface 60. Alternatively, the slit may terminate just short of the outer surface or the outer margin of the barbs.
As yet another alternative~ the slits could extend completely through the body but terminate just short of the rear end 18~ A great number of different arrangements may be used, all of which would allow the slits to open f~lly when the mandrel head is drawn i~ ~ ~e ~ody but which would hold the body's shape when the mandrel is in place but before it is drawn into it. That is, the head of the mandrel would fracture the slits to allow the body to expand as the anchor is set.
Having described this invention in detail, those skilled in the art will appreciate that numerous modifications may be made thereof without departing from its spirit. Therefore, it is not intended to limit the breadth of this invention to the single embodiment illustrated and described. Rather, it is intended that the scope of this invention be determined by the appended claims and their equivalents.
What is claimed is:
'
Claims (5)
1 A blind anchor comprising:
an elongated body made of a deformable material and having an annular cross-section providing a cylindrical inner surface, one end of the body having a circumferentially extending flange and constituting the front end of the body, a plurality of integrally formed circumferentially extending barb-like rings disposed along the length of the body rearwardly of the flange for biting into the wall of a hole in which the anchor is to be secured, a plurality of axially extending slits in the body extending from the rear end thereof forward to a point just rearwardly of the flange, a mandrel having a stem with a diameter slightly smaller than the inner diameter of the body and extending through the body and out the front beyond the flange so that it may be engaged by a pulling tool when the anchor is to be set, and a head on the rear end of the stem of the mandrel remote from the flange and having a diameter which increases in a direction away from the body, said diameter at the end of the head facing the flange not exceeding the inner diameter of the body so that the head may enter the body when the mandrel is pulled to cause the body to expand by spreading the body at the slits.
an elongated body made of a deformable material and having an annular cross-section providing a cylindrical inner surface, one end of the body having a circumferentially extending flange and constituting the front end of the body, a plurality of integrally formed circumferentially extending barb-like rings disposed along the length of the body rearwardly of the flange for biting into the wall of a hole in which the anchor is to be secured, a plurality of axially extending slits in the body extending from the rear end thereof forward to a point just rearwardly of the flange, a mandrel having a stem with a diameter slightly smaller than the inner diameter of the body and extending through the body and out the front beyond the flange so that it may be engaged by a pulling tool when the anchor is to be set, and a head on the rear end of the stem of the mandrel remote from the flange and having a diameter which increases in a direction away from the body, said diameter at the end of the head facing the flange not exceeding the inner diameter of the body so that the head may enter the body when the mandrel is pulled to cause the body to expand by spreading the body at the slits.
2. An anchor as defined in claim 1, further charac-terised by said body being made of a plastic material.
3. An anchor as defined in claim 1, further charac-terized by said slits extending partly through the body.
4. An anchor as defined in claim 1, further charac-terized by integrally formed circumferentially extending rings on the head for biting into the inner surface of the body to hold the head in the body when the head of the man-drel is pulled into it.
5. An anchor as defined in claim 1, further charac-terized by said slits extending completely through the body including the barb-like rings.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US43026082A | 1982-09-30 | 1982-09-30 | |
| US06/430,260 | 1982-09-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1221258A true CA1221258A (en) | 1987-05-05 |
Family
ID=23706767
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000428377A Expired CA1221258A (en) | 1982-09-30 | 1983-05-18 | Blind anchor |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1221258A (en) |
-
1983
- 1983-05-18 CA CA000428377A patent/CA1221258A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |