U.S. patent number 3,869,942 [Application Number 05/439,033] was granted by the patent office on 1975-03-11 for driving tool.
This patent grant is currently assigned to Textron Inc.. Invention is credited to Charles J. DeCaro.
United States Patent |
3,869,942 |
DeCaro |
March 11, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Driving tool
Abstract
The driving tool for installing fasteners in workpieces includes
a motor operated driver, a clutch mechanism engageable with the
driver, and an adapter including a wrenching mechanism and which
connects to the driving tool and cooperates with the clutch
mechanism to effectuate rotation of the wrenching mechanism. The
adapter includes means to engage the clutch before the fastener
engages the workpiece. The preferred means is a detent assembly
which is secured to the main body of the adapter and has a detent
ball which cooperates with an annular groove in the wrenching
mechanism. The main body or an extension thereof of the adapter
engages the workpiece prior to the fastener and as continued force
is applied, the clutch mechanism is engaged. Thereafter, the detent
overrides the groove permitting the wrenching mechanism and
fastener to further advance and the fastener is driven into the
workpiece. The adapter is adjustable for different length
fasteners.
Inventors: |
DeCaro; Charles J. (Brighton
Township, Beaver County, PA) |
Assignee: |
Textron Inc. (Providence,
RI)
|
Family
ID: |
23742999 |
Appl.
No.: |
05/439,033 |
Filed: |
February 4, 1974 |
Current U.S.
Class: |
81/54;
81/429 |
Current CPC
Class: |
B25B
21/00 (20130101); B25B 23/0064 (20130101) |
Current International
Class: |
B25B
23/00 (20060101); B25B 21/00 (20060101); B25b
013/00 (); B25b 021/00 () |
Field of
Search: |
;81/54 ;144/32 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
74,935 |
|
Jan 1961 |
|
FR |
|
1,923,712 |
|
May 1969 |
|
DT |
|
Primary Examiner: Jones, Jr.; James L.
Attorney, Agent or Firm: Webb, Burden, Robinson &
Webb
Claims
I claim:
1. An adapter for a fastener driving tool in which a clutch
mechanism is operable therebetween comprising:
A. a housing adapted for securement to the driving tool;
B. a main body having an opening therethrough slidably positioned
within the housing and adapted for engagement with a workpiece and
for extensible movement from the housing;
C. a wrenching mechanism positioned within the main body opening
including a forward fastener engaging end and a rearward clutch
engaging end and an annular groove thereabout intermediate said
ends; and
D. a detent assembly operative between the main body and the groove
in the socket member so that as the main body is urged from an
extended position into the housing, the detent engages the groove
to move the socket member into engagement with the clutch mechanism
and continued movement of the main body into the housing causes the
detent to override the groove and move relative to the wrenching
mechanism.
2. The adapter of claim 1 wherein said housing includes a slot
accommodating the detent assembly.
3. The adapter of claim 1, said detent assembly including a blind
chamber housing threadably engaging through the main body, a detent
ball cooperating with the chamber and said groove in the wrenching
mechanism and a spring positioned in the chamber to urge the ball
into said groove.
4. The adapter of claim 1 wherein the workpiece engaging portion of
the main body comprises a nonskid surface.
5. The adapter of claim 1 including an adjustment collar engageable
with the housing to form a stop for the main body as it advances
into the housing.
6. The adapter of claim 1 wherein the main body includes an annular
shoulder along the opening to accommodate a washer positioned on
the fastener in spaced relationship from a fastener head to assure
proper alignment of the fastener relative to the adapter and
workpiece.
7. The adapter of claim 1 including a coil spring positioned in the
housing to urge the main body into an extended position.
8. The adapter of claim 1 including an adjustment collar threadably
engaged to the main body at an end thereof.
9. The adapter of claim 3 wherein the main body includes a
plurality of spaced threaded openings to accommodate the detent
assembly housing at various fastener length adjustments.
10. The adjustment collar of claim 5 including a plurality of slots
spaced thereabout and positioned so one of said slots is in
registry with the housing slot at a given adjustment to accommodate
the detent assembly.
11. The adjustment collar of claim 7 including spaced indicia
thereon indicating a fastener length and adapted to align with
mating indicia on the main body to place an adjustment collar slot
in registry with the housing slot for a given fastener length.
12. A driving tool and fastener combination comprising:
A. a motor operated driver;
B. a clutch mechanism engageable with the driver;
C. an adapter connected to the driver and comprising
a. a housing having a slot therein and adapted for securement to
the driving tool;
b. a main body having an opening therethrough slidably positioned
within the housing and adapted for engagement with a workpiece and
for extensible movement from the housing;
c. a wrenching mechanism positioned within the main body opening
including a forward fastener engaging socket end and a rearward
clutch engaging end and an annular groove thereabout intermediate
said ends;
d. a detent assembly cooperating with the slot in the housing and
operative between the main body and the groove in the socket
member;
D. a fastener having a head engageable with the socket end, a shank
extending from the head and wholly within the main body opening and
a washer slidably positioned on the shank and positioned within the
main body opening in spaced relationship from the fastener head
whereby a forward pressure on the driving tool causes the socket
member to engage the clutch before the fastener engages the
workpiece.
13. The combination of claim 12 wherein the main body includes an
annular shoulder positioned about the opening to accommodate the
washer.
Description
FIELD OF THE INVENTION
My invention relates to driving tools and, more particularly, to
adapters for driving tools for self-drilling and tapping
fasteners.
DESCRIPTION OF THE PRIOR ART
There are a variety of known driving tools and adapters therefor
for setting fasteners and in particular fasteners of the
self-drilling and tapping type, hereinafter referred to as
self-drilling. The majority of the tools perform two functions in
common. First, the tools employ a clutching mechanism which is
engageable with the driver to cause rotation of the wrenching
mechanism which includes the socket; and second, the clutching
mechanism is engaged by forcing the fastener against the workpiece
to actuate the clutch. This latter common function has a
substantial number of drawbacks.
The self-drilling fastener itself is not as efficient as a standard
drill and is normally formed with a chisel-like point for
penetrating the workpiece. However, the thickness of the web which
forms the chisel-like point may vary appreciably from production
lot to production lot or the point may be nonsymmetrical with
respect to the fastener shank.. Both conditions create difficulties
in driving the fastener. A poor performing self-drilling screw has
a tendency to drift or walk from the point of intended application
and this tendency is particularly increased with increased web
thickness since substantial pressure must be placed on the screw to
activate the clutch which in turn imparts rotation to the wrenching
mechanism. Many applications for such self-drilling screws utilize
prefinished metal sheets and scoring of a prefinished sheet is not
acceptable to the building erector.
In addition, the fastener is normally held in alignment by a
magnetized hex socket of the wrenching mechanism and if the driving
tool is not held precisely perpendicular to the workpiece, the
tendency for the drill screw to walk or drift is further
aggrevated. The known performance of these tools results in the
fastener manufacturer and/or the consumer rejecting substantial
lots of self-tapping screws since a drill point which is only
slightly defective will perform poorly with the known driving
tools.
SUMMARY OF THE INVENTION
My invention overcomes the drawbacks of the known driving tool by
having the adapter rather than the fastener contact the workpiece
in order to actuate the wrenching mechanism. In addition, the tool
is automatically squared with the workpiece to assure a proper
alignment of the fastener relative to the workpiece. My invention
also results in the fastener attaining driving speeds prior to
engagement with the workpiece. My invention further provides for
the fastener to be maintained in alignment by support means in two
spaced locations to further insure proper installation. If the
fastener does wobble during installation, the amount of wobble is
normally less than the diameter of the fastener so the material is
either removed or in the severest condition the scoring is covered
by the fastener head. My invention can also be adjusted to
accommodate different length fasteners.
My invention is an adapter for a driving tool in which the adapter
bypasses the fastener to cause a wrenching mechanism to engage the
clutch before the fastener engages the workpiece. A main body
extensible within an outer housing of the adapter has connected to
it a detent assembly which includes a detent ball operable in an
annular groove on the wrenching mechanism. The main body or an
extension thereof engages the workpiece and continued pressure
forces the wrenching mechanism into operable engagement with the
clutching mechanism. Thereafter the detent overrides the groove
permitting the wrenching mechanism to advance toward the workpiece
driving the fastener thereinto.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation of the assembled tool;
FIG. 2 is an exploded view of the adapter;
FIG. 3 is a section through the adapter in its extended
position;
FIG. 4 is a section through the adapter in a clutch engaging
condition;
FIG. 5 is a section through the adapter when the detent overrides
its mating groove;
FIG. 6 is a section through the adapter when the fastener is fully
driven;
FIG. 7 is a section through the detent assembly; and
FIG. 8 is an elevation of a modified adjustment collar.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The driving tool, generally designated 10, comprises a motor driven
driver 12 and an adapter 14 which is connected thereto, FIG. 1. The
adapter 14 has four major components, namely the housing 16, the
main body 18 which is slidably positioned within the housing 16,
the wrenching mechanism 20 operable within the main body 18 and the
detent assembly 34 operable between the main body 18 and the
wrenching mechanism 20. The clutching mechanism is not shown in
detail since the particular type of clutching mechanism does not
form a part of this invention. The clutching mechanism is therefore
shown diagramatically as box 80 for purposes of illustration. In
existing tools the clutch mechanism is formed as an integral part
of the driver or as an integral part of the adapter, and either
arrangement is compatible with the inventive concept disclosed
herein.
The relationship of the various parts of the adapter 14 is best
seen in exploded FIG. 2. The housing 16 is tubular and internally
threaded at both ends. Specifically, internal threads 22 at one end
of housing 16 engage external threads (not shown) of the driver 12.
Internal threads 24 at the other end of housing 16 engage the
internal threads 48 of adjustment collar 46. Housing 16 includes an
elongated slot 26 which extends a portion of the length of housing
16 in a direction parallel to the longitudinal axis thereof.
Housing 16 is therefore rigidly secured to the driver 12.
The main body 18 is likewise tubular and is positioned within
housing 16 so as to be slidable therein and extensible therefrom.
Main body 18 includes an annular shoulder 28 along its rearward end
and annular shoulder 28 engages the forward section of housing 16
to limit the forward movement of body 18 and maintain body 18
within the housing 16 in the extended position of body 18. The
forward end of main body 18 includes external threads 30 which
engage annular ring 44, which is internally threaded. A nonskid and
nonmarring surface 56 is adhesively secured to the annular ring 44
and engages the workpiece surface 82. A clear-through central
cylindrical opening 88 of body 18 accommodates the wrenching
mechanism 20 and contains an annular shoulder 84 spaced slightly
inward of the forward end to accommodate the washer of a fastener
assembly.
A large coil spring 58 is positioned within housing 16 between the
driver (not shown) and the shoulder 28 of main body 18. Coil 58
urges the main body 18 to the fully extended position, FIG. 3,
after a fastener 74 is fully driven and the adapter 14 is removed
from the workpiece surface 82.
An adjustment collar 46 is positioned over the main body 18 and
threadably engages with the housing 16 as described hereinabove,
FIG. 2. Collar 46 includes a plurality of elongated spaced slots 50
extending inward from the rear end thereof parallel to slot 26 of
housing 16. The forward shoulder 86 of collar 48 includes indicia
52 which corresponds with indicia 54 on the main body 18. The
indicia 52 and indicia 54 relate to the length of the fastener and
when mating indicia are aligned, a specific slot 50 will be in
registry with slot 26 of the housing 16 to accommodate the detent
assembly 34.
A simplified adjustment collar 80 is illustrated in FIG. 8 where
the annular ring 82 corresponds to ring 44 of the earlier
embodiment. Ring 82 threadably engages main body 18 and therefore
serves as an adjustment for different fastener lengths depending on
the degree to which it is positioned along main body 18.
The wrenching mechanism 20, cylindrical in shape, is positioned
within the opening 88 of the main body 18 for engagement with the
clutching mechanism 80. Wrenching mechanism 20 includes a drive
coupling 40 positioned at one end and engageable with the clutch
mechanism 80. A hex socket 38 is recessed in the other end of
wrenching mechanism 20 to accommodate the hex head 72 of a fastener
70. An annular groove 42 extends about the wrenching mechanism 20
intermediate its ends and perpendicular to the longitudinal axis
thereof.
A detent assembly 34 includes a threaded body 60, a blind chamber
62 therein and a ball 64 adapted to cooperate with the blind
chamber 62 and the groove 42 of the wrenching mechanism 20, FIG. 7.
A coil spring 66 is positioned in the blind chamber to urge the
ball 64 out of chamber 62 and into the groove 42. The threaded body
60 includes a screwdriver slot 68 at its upper end and the threaded
body 60 threadably engages one of the threaded openings 32 in the
main body 18. The various openings 32 are utilized for the
different fastener lengths employed. This could also be
accomplished by using different wrenching mechanisms for each
fastener length or by utilizing a plurality of grooves 42. The
threaded body 60 is also positioned within the slot 26 of housing
16 and the slot 50 of adjustment collar 46. In this manner the
detent assembly 34 not only permits bypassing the fastener 70 to
engage the clutch 80, as will be described hereinafter, but the
detent assembly 34 also prevents relative rotative movement between
the main body 18, housing 16 and adjustment collar 46.
A typical fastener 70 for use with the adapter 14 has a hex head 72
and a threaded shaft 74 which terminates in a drill point 76. A
washer 78 is positioned on the fastener 70 in spaced relationship
from the hex head 72.
The operation of my adapter is illustrated in FIGS. 3-6. The
fastener 70 is manually positioned in the main body 18 so that the
fastener head 72 fits in the accommodating socket 38 of the
wrenching mechanism 20. At the same time, the washer 78 is limited
by the annular shoulder 84 in the opening of the main body 18 to
assure the spaced relationship from hex head 72 and thereby assure
proper alignment. The driving tool 10 is then positioned against
the workpiece surface 82 so that the nonskid surface 56 engages it.
At this position, FIG. 3, the detent assembly 34 is in engagement
with the groove 42 of the wrenching mechanism 20 and the drill
point 76 is still internal of the main body 18.
As the operator exerts pressure to the driving tool 10, the main
body 18 retracts into the housing 16 carrying with it the wrenching
mechanism 20 by means of the detent assembly 34, FIG. 4. This
retraction continues until the driving coupling 40 of the wrenching
mechanism 20 engages the clutch to cause rotation of the wrenching
mechanism 20 and fastener 70.
Thereafter the detent overrides the groove 42 as the ball 64
contracts the spring 62 within the blind chamber 66 of the threaded
body 60, FIG. 5, and then the drill tip 76 penetrates the work
surface. The force opposing the penetration of the fastner 70 into
the workpiece and the continued pressure by the operator maintain
the wrenching mechanism 20 in engagement with the clutch 80. The
fastener 70 is driven fully into place and the clutch is disengaged
through clutch mechanism 80 in the standard manner. Thereafter coil
spring 58 urges the main body 18 to the fully extended position in
which the detent assembly 34 again engages groove 42.
The adjusting collar 46 can be threaded into or out of the housing
16 or collar 80 can be threaded onto or out of main body 18 to
accommodate different length fasteners for the respective
embodiments. Likewise detent assembly 34 is threadably engaged in
the proper opening 32 for the particular length fastener. Since
fasteners are of standard lengths, this information is reflected on
the respective indicia 52 and 54 so that mating indicia can be
aligned for each given fastener length. A window can also be
inserted in the main body 18 in the area of the hex socket 38 so
the operator can visually see the loading of the fasteners.
* * * * *