Information
-
Patent Grant
-
6481691
-
Patent Number
6,481,691
-
Date Filed
Thursday, September 28, 200023 years ago
-
Date Issued
Tuesday, November 19, 200221 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Hai, III; Joseph J.
- Shanley; Daniel
Agents
-
CPC
-
US Classifications
Field of Search
US
- 254 28
- 254 18
- 254 121
- 254 128
- 254 134
- 254 20
- 227 63
- 227 134
- 029 252
-
International Classifications
-
Abstract
A fastener puller capable of removing fasteners embedded in a material having a surface, the puller having a handle, a horn having a wedge, connecting means form mounting the horn to the handle and an elongated ram slidably mounted with respect to the handle. As the ram is moved along a slide path, the ram abuts the horn causing the wedge to be forced underneath the head of a fastener. As the ram continues along the slide path and contacts the surface, the horn and handle are pushed away from the surface causing the fastener to be pulled out of the material.
Description
FIELD OF THE INVENTION
This invention relates to an apparatus for pulling fasteners and more particularly to hand tools for pulling upholstery staples and nails.
BACKGROUND OF THE INVENTION
Fasteners, such as staples and nails, that have been embedded in wood are used in a wide variety of applications. Fore example, fabric is often affixed to the wooden frames of upholstered furniture using upholstery staples. Upholstery staples have elongated points so as to be embedded deep into a wood frame. Upholstery staples are embedded deep into a wooden frame so as to maintain the fabric in place for a long time.
When reupholstering furniture however, it is often very difficult to remove the staples so as to place new fabric on the frame because the staples are embedded very deep into the wood. Generally, the staples are removed by pliers, flat screwdrivers and awls. These tools can make the staple removal process very time-consuming. In fact, it can take nearly one hour for one person to remove the staples from a standard wing chair. In many situations, the staples are left in the frame and a new staple is embedded in the frame at a different location for the new fabric. This latter option is considered to be poor upholstery practice.
Two hand tools have been developed to assist in this process. In U.S. Pat. No. 4,245,817 to Peoples a pneumatic staple puller was proposed. This used two claw members to pierce underneath the crown of the staple and to lift the staple from the wood. U.S. Pat. No. 4,637,538 to Wagner proposed a hand-held tool which is used to drive a wedge underneath the crown of the staple from the side. The Peoples staple puller requires great precision and the ends of the claw members are likely to break after repeated removals. The Wagner staple puller suffers from a disadvantage that it is applied at an angle to the surface in which the staple is embedded. As a result, there will be situations where there will not be room for the main housing of the staple puller because the frame of the furniture will be in the way. As well, the chisel-shaped end portion of the puller must be manually lodged underneath the crown of the staple before the device is activated. This may not be possible when the staple is deeply embedded in the material.
As well, it is also difficult to remove nails embedded in wood. Generally, the claw of a hammer is used to pull a nail from wood. However, if the head of the nail is below the surface of the wood, it is difficult to position the claw underneath the head of the nail.
Accordingly, there is a need for a pneumatically powered fastener puller which is fast, easy to use and may be applied perpendicular to the surface in which the fastener is embedded.
SUMMARY OF THE INVENTION
The present invention is accordingly directed to a fastener puller for removing a fastener such as a staple or a nail embedded in a material having a surface.
The subject fastener puller has a handle and connecting means fixedly attached to the handle for connecting a horn to the handle. The horn is mounted on the connecting means and has an elongated stem with an end and a wedge at the end of the stem. The wedge is adapted to fit underneath the head of a fastener. The horn is mounted so that it is moveable relative to the handle from a disengaged horn position to an engaged horn position. An elongated ram is slidably mounted with respect to the handle for longitudinally slidable movement along a slide path from a first ram position through a second ram position to a third ram position. The horn is positioned relative to the ram so that when the ram moves from the first position to the second position, the ram abuts the horn and causes the horn to move from the disengaged position to the engaged position. The ram is positioned so that when the ram moves from the second position to the third position, the ram is in continuous contact with the surface.
The fastener puller may also comprise pneumatic or electrical means for moving the ram along the slide path.
The fastener puller may also have a guide rod fixedly mounted with respect to the handle. The guide rod has a slot adapted to fit about the head of an embedded fastener.
The horn of the fastener puller may be biased to the disengaged position by a biasing member to the disengaged position.
In another aspect of the invention, the staple puller may have an adjusting member for adjusting the position of the horn with respect to the guide rod.
In an alternative embodiment to the invention, the staple puller may have a ram handle with an elongated ram fixedly mounted on the ram handle. A pull member is slidably mounted with respect to the ram handle and a horn is pivotally mounted to the pull member. The horn has an elongated stem and a wedge at the end of the stem. The wedge of the horn is adapted to fit underneath the crown of the staple. The horn is pivotable from a first horn angle relative to the ram to a second horn angle. The horn is positioned so that when the ram is pushed towards the surface, the ram abuts the horn and moves the horn from the first horn angle to the second horn angle.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example only, with reference to the following drawings in which:
FIG. 1
is a front view of a staple puller in accordance with a preferred embodiment of the present invention with the trigger removed;
FIG. 1A
is a bottom view of the base of a component part of the staple puller of
FIG. 1
;
FIG. 2
is a partial sectional side view of the staple puller of
FIG. 1
;
FIG. 3
is a side view of the component of
FIG. 2
prior to operation;
FIG. 4
is a side view of the component of
FIG. 3
in a second position;
FIG. 5
is a side view of the component of
FIG. 3
in a third position;
FIG. 6
is a side view of an alternative preferred embodiment of a tool extension in accordance with an aspect of the present invention;
FIG. 7
is a front view of a further alternative embodiment of the present invention;
FIG. 8
is a partial sectional front view of a further alternative embodiment of the present invention;
FIG. 9
is a partial sectional side view of the embodiment shown in
FIG. 8
in the first position;
FIG. 10
is a partial sectional side view of the embodiment shown in
FIG. 8
in the second position;
FIG. 11
is a partial sectional side view of the embodiment shown in
FIG. 8
in the third position;
FIG. 12
is a side view of an alternative preferred embodiment of a tool extension in accordance with an aspect of the present invention;
FIG. 13
is a bottom view of the horn of the embodiment shown in
FIG. 12
;
FIG. 14
is a side view of the lower portion of another embodiment of the horn;
FIG. 15
is a bottom view of an alternative embodiment of the horn for use in a nail puller.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to
FIGS. 1 and 2
, illustrated therein is a pneumatic fastener puller
20
made in accordance with a preferred embodiment of the present invention. Except where otherwise stated, fastener puller
20
will be described as a staple puller. Pneumatic staple puller
20
includes an air inlet port
22
, a housing
24
, a trigger
26
, and a tool extension
28
. Staple puller
20
may be connected to a source of pressurized air via air inlet port
22
.
In this application, the perpendicular direction is generally indicated by tool extension
28
with a material
72
defining the bottom of FIG.
2
.
Housing
24
is composed of handle
30
and cylinder housing
32
. An air flow path extends from air inlet port
22
through handle
30
to a cylinder
33
positioned within cylinder housing
32
. Trigger
26
, when depressed, allows pressurized air to flow from air inlet port
22
through housing
24
and into cylinder
33
. A piston
35
is positioned within cylinder
33
and is forced towards the lower end of cylinder
33
as the pressurized air enters cylinder
33
.
Tool extension
28
comprises a ram
34
, U-bracket
36
, pillow bushing
38
, horn
40
and plunge rod
42
.
Plunge rod
42
is affixed to the bottom of cylinder housing
32
by means of U-bracket
36
. Plunge rod
42
is composed of an upper rod
44
and a guide rod
46
. The upper end of upper rod
44
is affixed to U-bracket
36
by bolts (not shown). Plunge rod
42
extends downwardly from cylinder housing
32
. The bottom end of guide rod
46
is shaped to fit around a head or crown
50
of a staple
52
while allowing the base of horn
40
to pass underneath crown
50
.
FIG. 1A
shows a sample cross-section of the bottom end of guide rod
46
adjacent to the four comers of crown
50
. It will be appreciated that other configurations for the bottom end of guide rod
46
can be used so long as lateral motion of the crown
50
of staple
52
relative to the guide rod may be prevented.
Ram
34
is composed of a ram stem
54
and a ram base
55
. Ram stem
54
is an elongated member extending into cylinder housing
32
and is affixed to piston
35
therein. Ram base
55
is shaped to surround plunge rod
42
in a channel therein, as shown in FIG.
1
A.
Horn
40
comprises a horn stem
56
and a horn wedge
58
. Horn
40
is mounted on pillow bushing
38
. Pillow bushing
38
is mounted between plunge rod
42
and ram
34
by means of a horn pin
62
passing through plunge rod
42
and pillow bushing
38
. Pillow bushing
38
is provided with a groove
64
into which a horn mount
66
protrudes. Groove
64
lies adjacent to plunge rod
42
and is sized to fit the width of horn stem
56
when horn
40
is parallel to plunge rod
42
. Guide rod
46
is provided with a horn channel
65
into which horn stem
56
will fit when in the vertical position.
The upper end of horn stem
58
is provided with an indentation
70
. Horn mount
66
fits within indentation
70
such that horn
40
pivots about horn mount
66
. A biasing member such as a leaf spring
68
is mounted between pillow bushing
38
and plunge rod
42
and is affixed at its end to approximately the midpoint of horn stem
56
. Leaf spring
68
biases horn wedge
58
at a first angle away from guide rod
46
to a disengaged position.
Horn
40
is mounted such that horn wedge
58
is positioned to fit underneath the crown
50
of a staple
52
located within guide rod
46
when horn
40
is pivoted towards plunge rod
42
.
In operation, the lower end of guide rod
46
is placed over the crown
50
of staple
52
embedded in a material
72
. Staple puller
20
is oriented as shown in
FIG. 2
with handle
30
generally parallel to a surface
74
of material
72
and cylinder housing
32
generally perpendicular to surface
74
. Air inlet port
22
is connected to a pressurized air source. As shown in
FIGS. 2 and 3
, ram
34
is placed in a first ram position within cylinder housing
32
such that horn wedge
58
is allowed to assume its disengaged position away from the central axis of plunge rod
42
. When trigger
26
is depressed, highly pressurized air is permitted to enter air inlet port
22
and passes into cylinder
33
. The pressure of the air feeding cylinder
33
forces piston
35
and ram
34
which is attached thereto downwards. Ram
34
in its downward motion from its first ram position to a second ram position as shown in
FIG. 4
, frictionally engages horn stem
56
forcing horn wedge
58
towards the staple
52
located at the bottom of guide rod
46
. As ram
34
descends rapidly to the second ram position, horn
40
is pivotally forced from the disengaged position to the engaged position and horn wedge
58
is forced underneath crown
50
of staple
52
lifting it upwards along the wedge. Horn wedge
58
is received within the base of guide rod
46
. Horn stem
56
is also received in horn channel
65
. Crown
50
of staple
52
is held in place between guide rod
46
and horn wedge
58
. At the second ram position, ram
34
is in contact with surface
74
. As air continues to flow into cylinder
33
, ram
34
is forced downwards to a third ram position as shown in FIG.
5
. As ram
34
is forced against the surface
74
of material
72
, housing
24
of pneumatic staple puller
20
is forced upwards away from material
72
. As housing
24
is pushed upwards, horn
40
and plunge rod
42
are also pushed away from the surface. As horn wedge
58
is underneath crown
50
of staple
52
, staple
52
is pulled out of material
72
.
It will be appreciated that numerous variants of the above invention may be made.
FIG. 6
shows an alternative embodiment of the present invention with a different configuration of the horn. In this embodiment, horn
80
is a prestressed metallic member bent away from plunge rod
42
. Essentially, horn
80
acts as a leaf spring. Horn pin
62
affixes pillow bushing
81
and horn
80
to plunge rod
42
. As ram
34
moves towards surface
74
, horn
80
is pushed inwards towards plunge rod
42
so that horn wedge
58
passes underneath crown
50
of staple
52
.
The invention is not limited solely to pneumatically-powered devices. In one variant of the present invention shown in
FIG. 7
, ram
34
is affixed to a core
37
within a cylindrical solenoid
39
. A trigger (not shown) causes a current to pass through the solenoid
39
, resulting in a magnetic force driving core
37
and ram
34
downwards. The downward force applied to the ram
34
within the solenoid
39
decreases as core
37
nears the bottom of solenoid
39
and there may be insufficient power to drive ram
34
onto the material and push the staple puller upwards to remove the staple. This drawback may be overcome by increasing the power of the solenoid, but this may cause too great an initial downwards force applied to the ram, potentially causing damage to the surface of the material or causing the horn to shear the crown off the staple. A pneumatically powered staple puller will allow for a more constant force. As well, a pneumatically powered staple puller lends itself well to the upholstery industry as many upholstery tools such as staple guns are pneumatically powered.
An optional feature for adjusting the height of the horn is shown in
FIGS. 1-5
. Tool extension
28
is provided with a circular adjustment member
90
adjacent to plunge rod
42
and affixed to horn pin
62
. Horn pin
62
is an eccentric pin. When adjustment member
90
is rotated, the rotation of eccentric horn pin
62
causes pillow bushing
38
to move up and down thus adjusting the height of horn wedge
58
relative to the base of guide rod
46
. Therefore, if staple
52
is deeply embedded in material
72
, adjustment member
90
can be rotated so that horn wedge
58
is lower than the base of guide rod
46
. When ram
34
is driven down, horn wedge
58
will be driven slightly below surface
74
of material
72
so that it passes below crown
50
of staple
52
.
A further alternative embodiment of a staple puller
100
is shown in
FIGS. 8
to
11
. Staple puller
100
comprises a plunge member
102
and a pull member
104
. Plunge member
102
is capable of slidable vertical movement with respect to pull member
104
.
Plunge member
102
is composed of handle
106
, bushing
108
and ram
110
. Handle
106
is provided with a central cavity
112
and a cylindrical cavity
114
passing downwards through the base of handle
106
. Cylindrical cavity
114
is defined at its top by the cylindrical bushing
108
at its bottom by the cylindrical ram
110
. The diameter of bushing
108
is less than the diameter of ram
110
.
Pull member
104
is composed of a finger grip
116
, a plunge rod
118
, a horn
120
mounted on a horn pin
122
, a return spring
124
and a leaf spring
126
. Finger grip
116
is generally coplanar with handle
106
and is positioned within central cavity
112
. Plunge rod
118
is generally cylindrical in shape with a slotted or grooved base designed to receive a horn wedge
128
and a crown
130
of a staple
132
. Plunge rod
118
is affixed to the base of finger grip
116
and extends through cylindrical cavity
114
within cylindrical bushing
108
and ram
110
. Horn pin
122
is mounted near the midpoint of the portion of the plunge rod
118
which extends below handle
106
. Leaf spring
126
is mounted to plunge rod
118
and abuts horn
120
such that horn wedge
128
pivots away from the base of plunge rod
118
.
The base of return spring
124
is affixed to the outer surface of plunge rod
118
above horn pin
122
such that a portion of plunge rod
118
passes through the centre of return spring
124
. The top of return spring
124
abuts the base of cylindrical bushing
108
. Optionally, return spring
124
is affixed to the base of cylindrical bushing
108
. Return spring
124
is sized such that when it is in its resting position (i.e. not compressed or stretched), the base of finger grip
116
abuts the top of cylindrical bushing
108
.
In use, the user grasps handle
106
and positions the staple puller
100
such that the base of plunge rod
118
is placed about the crown
130
of staple
132
which is embedded in material
134
as shown in FIG.
8
. The user then pushes downwards firmly such that ram
110
slides over plunge rod
118
and forces horn
120
inwards until the base of ram
110
is flush with a top surface
134
of material
132
as shown in FIG.
9
. Horn wedge
128
passes underneath the crown
130
of staple
132
pulling the staple slightly out from material
134
. Because plunge member
102
is pushed downwards with respect to pull member
104
, return spring
124
is compressed.
At this stage the user maintains a downwards force on handle
106
but releases some of their fingers to grasp finger grip
116
. The user pulls finger grip
106
upwards as seen in FIG.
10
. As a result, staple
132
which is grasped between horn wedge
128
and the base of plunge rod
118
is pulled out of material
134
. The user may then release the downwards force on handle
106
, allowing the force of return spring
124
to direct pull member
104
to its resting position.
FIG. 12
shows a further alternative embodiment of the present invention. In this embodiment, a dual-wedge structure is used to remove the staple. Horn
140
is comprised of two stems
154
,
156
having inwardly facing horn wedges
142
,
143
respectively. Horn
140
is bent at its midpoint and mounted to guide rod
144
by horn pin
146
. Ram
148
is a rectangular body which completely surrounds guide rod
144
and horn
140
when lowered. When ram
148
is driven downwards, horn wedges are driven inwards towards staple
52
and are embedded under crown
50
. Horn wedges
142
,
143
are designed such that they pass by one another as they are driven beneath crown
50
. An example configuration of horn wedges
142
,
143
is shown in FIG.
13
. In this configuration, horn wedge
142
is composed of two protruding wedge portions
150
along the sides of wedge
142
while horn wedge
143
has a protruding central wedge portion
152
. Wedge portion
152
is shaped to fit between wedge portions
150
as shown in FIG.
13
. Other configurations will be obvious to those skilled in the art. As with the other embodiments, as ram
148
continues its downwards motion, guide rod
144
moves upwards and pulls staple
52
out of material
72
.
FIG. 14
shows an alternative embodiment of the horn used in the various staple pullers described herein. Horn
160
has a stem
162
with a wedge
164
as previously described. Wedge
164
has a top surface
168
. Top surface
168
is provided with an indentation or notch
166
extending across the width of the wedge for receiving the crown of the staple. As wedge
164
is driven underneath the crown of the staple, the crown slides upwards along top surface
168
. When the crown of the staple passes over notch
166
, the crown is caught and maintained in the notch. Any downward sliding of the crown is thus prevented. This version of the horn allows the staple to be stabilized in one position along wedge
164
when the staple is pulled out of the material. This is advantageous as the staple will tend to slide down top surface
68
of wedge
164
as the staple is pulled out if the material. Otherwise, the staple may press against the guide rod as it is removed, potentially causing the staple puller to jam. It is to be understood that various notch configurations can be used as is known to those skilled in the art.
FIG. 15
shows a further alternative embodiment of the lower end of the horn for use in a powered nail puller. Wedge
182
of horn
180
is provided with a V-shaped notch
184
and wedge protrusions
186
. As the ram forces the horn to a perpendicular position with respect to the surface, the wedge protrusions
186
pass underneath the head of the nail, lifting it out of the surface as the head slides up the wedge. The shank of the nail fits within notch
184
and horn
180
is positioned so that the movement of wedge
182
towards the nail does not shear off the head of the nail. As the ram abuts the surface, forcing the handle away from the surface, the nail will be pulled from the material. Depending on the length of the nail, the nail may be completely pulled from the material. If it is desired to pull longer nails from the material, a nail puller having a longer ram and a corresponding longer cylinder may be used. It will be obvious to those skilled in the art that other wedge configurations are possible for use in nail pullers.
It is to be understood that a wide variety of cross-sectional shapes of rams and guide rods are available to be used in any of the embodiments described.
It is to be understood that what has been described are preferred embodiments to the invention. The invention nonetheless is susceptible to certain changes and alternative embodiments fully comprehended by the spirit of the invention as described above, and the scope of the claims set out below.
Claims
- 1. A fastener puller for removing a fastener embedded in a material having a surface, the fastener puller comprising:a housing, said housing including a cylinder and a piston moveable within said cylinder, said cylinder fixedly mounted to said housing, a horn, said horn comprising an elongated stem, said stem having an end, a wedge at said end, said wedge adapted to fit underneath a head of the fastener, said horn being mounted for generally pivotable movement relative to said housing from a disengaged horn position to an engaged horn position; a ram, said ram slidably mounted with respect to said housing for longitudinal slidable movement along a slide path from a first ram position through a second ram position to a third ram position relative to said housing, wherein said ram is mounted for said longitudinal movement with said piston relative to said cylinder and said horn is mounted for longitudinal movement with said cylinder relative to said piston, said horn positioned relative to said ram so that when said ram moves from said first ram position to said second ram position, said ram abuts said horn and causes said horn to move generally pivotally from said disengaged horn position to said engaged horn position; said ram located to engage said surface when in said second ram position and when in said third ram position so that as said ram moves from said second ram position to said third ram position, said horn moves longitudinally with respect to said ram away from said surface.
- 2. A fastener puller as claimed in claim 1 further comprising pneumatic means for moving said ram along said slide path.
- 3. A fastener puller as claimed in claim 1 further comprising electrical means for moving said ram along said slide path.
- 4. A fastener puller as claimed in claim 1 further comprising a guide rod, said guide rod fixedly mounted with respect to said housing, said horn is mounted to said guide rod, said guide rod having an end remote from said housing, said guide rod comprising a slot at said end and said slot is adapted to receive said fastener as said fastener is removed from said material.
- 5. A fastener puller as claimed in claim 4 wherein the said horn is biased to said disengaged horn position.
- 6. A fastener puller as claimed in claim 5 wherein said stem of said horn is flexibly deformable, and said horn moves generally pivotably from said disengaged position to said engaged position by flexible deformation of said stem.
- 7. A fastener puller as claimed in claim 5 further comprising a biasing member for biasing said horn to said disengaged horn position.
- 8. A fastener puller as claimed in claim 4 further comprising an adjusting member for adjusting the longitudinal position of the horn relative to the guide rod.
- 9. A fastener puller as claimed in claim 1 further comprising a second horn said second horn having a second stem having an end, and a second wedge at said end, said second wedge adapted to fit underneath the head of the fastener, said second horn mounted for longitudinal movement with said cylinder relative to said piston, the second horn being moveable relative to said housing from a disengaged second horn position to an engaged second horn position, said second horn positioned relative to said ram so that when said ram moves from the first ram position to the second ram position, the ram abuts said second horn and causes said second horn to move from the disengaged second horn position to said engaged second horn position.
- 10. A fastener puller as claimed in claim 1 wherein the fastener is a staple having a crown, and the head of the fastener is the crown of the staple.
- 11. A fastener puller as claimed in claim 10 wherein the wedge comprises an indentation for receiving the crown of the staple when the horn is in the engaged position.
- 12. A fastener puller as claimed in claim 1 wherein the fastener is a nail having a head.
- 13. A staple puller for removing a staple embedded in a material having a surface, the staple puller comprising:a plunge member composed of a ram handle and an elongated ram fixedly mounted with respect to the ram handle, the elongated ram having a lower end; a pull member slidably mounted with respect to the plunge member and said pull member including a plunge rod and a horn, said horn pivotally mounted with respect to the plunge rod, the horn comprising an elongated stem, said stem having an end, and a horn wedge at said end, the wedge adapted to fit underneath a crown of the staple, said horn pivotable from a first horn position relative to the plunge rod to a second horn position, said horn positioned so that when the elongated ram is pushed towards and contacts the surface, aid elongated ram abuts the horn and causes said horn to move from said first horn position to said second horn position to engage said staple and said pull member located with respect to said plunge member so that said pull member may be moved away from the surface to remove the staple from the surface while the end of the plunge member remains in contact with the surface.
- 14. A staple puller as claimed in claim 13 wherein said plunge rod comprises a slot adapted to fit about a crown of a staple.
- 15. A staple puller as claimed in claim 13 wherein the horn is biased to said first horn position.
- 16. A staple puller as claimed in claim 14 further comprising a biasing member for biasing the horn to said first horn position.
- 17. A staple puller as claimed in claim 14 further comprising an adjusting member for adjusting the position of the horn relative to the guide rod.
US Referenced Citations (11)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0030474 |
Jan 1990 |
JP |
404002476 |
Jan 1992 |
JP |