US4014225A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power-driven screwdriver
Assignee: Bulten Kanthal AB
•
Filing: 1975-03-24
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Granted: 1977-03-29
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Expires: 1995-03-24
Abstract
Abstract A screw tightening apparatus comprising a motor-driven tool, a screw magazine for screws affixed to a strip-like carrier, and a screw advancing and tightening means for advancing the screws one at a time to a preparatory screw tightening position in which a bit portion of the motor-driven tool may engage with the screw for tightening thereof. The screw advancing and tightening means comprises two axially movable portions, one of which is secured to the tool and the other one of which carries the screw magazine and a spring biased screw advancing mechanism. A push and pull member on the stationary portion is adapted to cooperate with a dog means on the spring biased screw advancing mechanism for advancement of a new screw at the end of the retractive movement of the movable parts into a rest position, subsequent to a completed driving home of a screw. A latch holds the screw advancing mechanism temporarily in a retracted rest position during tightening of the screw and the first portion of the movement of the relatively movable portions into a retracted rest position and releases said screw advancing mechanism for advancement of a screw, at the final stage of said movement.
Inventors
- 👤 Sixten H. Lejdegard
- 👤 Nils E. Henriksson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:46
CPC Classifications
B; B25; B25B; B25B23/00; B25B23/02; B25B23/04; B25B23/045
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
174 words
A power-driven screwdriver for use with an assemblage of screws affixed to a strip-like screw-carrying medium, comprising: a. a body engageable with a workpiece; b. a screwdriver bit mounted in said body for rotational and axial movement therein, and having drive means by which said bit may be rotatably driven; c. stationary guide means on said body for guiding an end portion of the assemblage of screws remotely from the axis of said bit such that the next-to-be driven screw is guided and supported only by the strip-like medium in registration with said bit to be detached therefrom and driven into the workpiece by said bit; and d. automatic index means on said body for normally holding said end portion of the assemblage of screws against movement in either direction in said guide means, and operative on the screw-carrying medium to apply an indexing force thereto, only after and under the control of the axial retractive movement of the bit, for the distance needed to advance the next of the screws into said registration.
Claim 2
Dependent Claim
174 words
A power-driven screwdriver for use with an assemblage of screws affixed to a strip-like screw-carrying medium, comprising: a. a body engageable with a workpiece; b. a screwdriver bit mounted in said body for rotational and axial movement therein, and having drive means by which said bit may be rotatably driven; c. stationary guide means on said body for guiding an end portion of the assemblage of screws remotely from the axis of said bit such that the next-to-be driven screw is guided and supported only by the strip-like medium in registration with said bit to be detached therefrom and driven into the workpiece by said bit; and d. automatic index means on said body for normally holding said end portion of the assemblage of screws against movement in either direction in said guide means, and operative on the screw-carrying medium to apply an indexing force thereto, only after and under the control of the axial retractive movement of the bit, for the distance needed to advance the next of the screws into said registration.
Claim 3
Dependent Claim
60 words
A screwdriver according to claim 1 including second guide means secured to said body in normally spaced relation to all the screws, but engageable by and receptive of the tip of a screw as it is axially driven from the screw-carrying medium before it is fully detached therefrom, whereby the driven screw is subsequently driven through said second guide means.
Claim 4
Dependent Claim
36 words
A screwdriver according to claim 2 in which said second guide means comprises a pair of axially stationary radially movable coacting jaws jointly defining a passage for the screw, and spring means urging said jaws together.
Claim 5
Dependent Claim
39 words
A screwdriver according to claim 3 in which said jaws further define a cam surface engageable by the screw tip leading to said passage, and having a shape corresponding to the under side of the head of the screw.
Claim 6
Dependent Claim
24 words
A screwdriver according to claim 3 including a movable latching member disposed between said jaws to hold them apart for replacement of said bit.
Claim 7
Dependent Claim
41 words
A screwdriver according to claim 3 in which said second guide means includes a nose portion supporting said jaws and said spring means, and detachably secured to said body, whereby said second guide means is removable therefrom as a unified assembly.
Claim 8
Dependent Claim
37 words
A screwdriver according to claim 1, said body having a stationary hand-gripping portion formed as a tubular extension encircling said bit, and a plunger member supporting said drive means and slidably non-rotatably mounted within said tubular extension.
Claim 9
Dependent Claim
163 words
A screwdriver according to claim 1 in which said automatic index means comprises: a. operating means responsive to the retractive movement of said bit; b. a slider guided by said body for reciprocable movement in the direction of the length of the assemblage and connected to said operating means to be driven thereby; c. resilient driving finger means having a driving face for acting on the assemblage in the direction of its length at a screw in the assemblage advancing direction during retractive movement of said bit, and a camming face for passing by a screw in the assemblage during advancing movement of said bit, said driving finger means being secured to said slider; and d. resilient stop finger means fixed to said body and having a stop face acting on the assemblage at a screw in the assemblage during advancing movement of said bit, and a camming face passed over by a screw in the assemblage during retractive movement of said bit.
Claim 10
Dependent Claim
38 words
A screwdriver according to claim 7 which includes a pin and slot connection in said plunger member and said body for preventing relative rotation therebetween and for limiting the travel of said bit in both said axial directions.
Claim 11
Dependent Claim
41 words
A screwdriver according to claim 7 in which said automatic index means comprises: a. means for laterally shifting the assemblage b. means responsive to the relative positions of said body and said plunger member and connected for reciprocating said assemblage-shifting means.
Claim 12
Dependent Claim
125 words
A screwdriver according to claim 10 in which said operating means comprises: a. an impact member secured to said plunger member body; b. a lever pivoted on said body and coupled to said shifting means; c. a spring biasing said lever in a strip-shifting direction; d. a latch on said body for trapping said lever in a spring-loaded position; and e. a dog slidably disposed on said body and having a lost-motion connection with said impact member, said dog being engageable with said lever and with said latch, whereby said impact member, acting through said lost-motion connection, loads said spring and traps said lever by said latch during bit advancement, and said impact member acting through said lost-motion connection releases said latch during bit retraction.
Claim 13
Dependent Claim
44 words
A screwdriver according to claim 11 in which said pivoted lever comprises a bell crank so that movement of said plunger member in one direction is converted to movement of said shifting means in a direction at a right angle to said one direction.
Claim 14
Dependent Claim
22 words
A screwdriver according to claim 11 including a post on said body to which one end of said biasing spring is supported.
Claim 15
Dependent Claim
26 words
A screwdriver according to claim 11 in which said latch is spring-biased for pivoting about an axis parallel to the axis of rotation of said bit.
Claim 16
Dependent Claim
25 words
A screwdriver according to claim 11 in which said latch has a cam surface engageable by said pivoted lever preparatory to the lever's being trapped.
Claim 17
Dependent Claim
25 words
A screwdriver according to claim 11 in which said latch has a cam surface engageable by said dog to effect release of said pivoted lever.
Claim 18
Dependent Claim
78 words
A screwdriver according to claim 11 in which said first lost-motion connection comprises an end face on said dog and an end face on said impact member which are normally spaced apart and engageable with each other during bit advancement, and a pull rod fixed at one end to one of said end faces, and extending slidably through an internally shouldered opening in the other of said end faces, and having a formation for engaging such internal shoulder.
Claim 19
Dependent Claim
27 words
A screwdriver according to claim 11 in which said dog has an abutment away from said impact member, and engageable with a portion of the pivoted lever.
Claim 20
Dependent Claim
26 words
A screwdriver according to claim 11 in which said dog has an abutment facing toward said impact member and engageable with a portion of said latch.
Claim 21
Dependent Claim
70 words
A screwdriver according to claim 11, said tubular hand gripping portion having a cylindrical compartment within which said bit and said spring are disposed, and a base portion carrying said guide means and having a further compartment enclosing said lever and said shifting means, there being a wall separating said compartments, said dog extending therethrough and being slidably guided thereby, and a portion of said spring extending through said wall.
Claim 22
Dependent Claim
22 words
A screwdriver according to claim 20 including a dirt seal between said compartments through which a portion of said biasing spring extends.
Claim 23
Dependent Claim
29 words
A screwdriver according to claim 20 in which said base portion of said body includes a cover supporting said trapping latch and enclosing a side of said further compartment.
Claim 24
Dependent Claim
28 words
A screwdriver according to claim 11 including a pin and slot connection between said dog and said body for precluding rotation of said dog about its displacement axis.
Claim 25
Dependent Claim
32 words
A screwdriver according to claim 1 in which said body has a convexly curved portion over which spent screw-carrying medium, used to hold the screws in alignment with said bit, may pass.
Claim 26
Dependent Claim
36 words
A screwdriver according to claim 1 which includes a separator rod secured to said body and disposed to be between spent strips of screw-carrying medium used to hold the screws jointly in alignment with said bit.
Claim 27
Dependent Claim
179 words
A screw tightening apparatus of the type comprising a motor-driven tool, a screw magazine for screws which are affixed to a strip-like screw carrying medium, and a screw advancing and tightening means for advancing the screws one at a time to a preparatory screw tightening position in which a bit portion of the motor-driven tool may be brought into engagement with the screw for tightening thereof, wherein the screw advancing and tightening means comprises two relatively axially movable but relatively non-rotatable portions, one of which is secured to the motor-driven tool, and the other one of which carries the screw magazine and a spring biased screw advancing mechanism, and wherein the stationary portion is provided with a push and pull member, adapted to cooperate with a rod shaped dog means of said spring biased screw advancing mechanism on tightening of a screw and to trigger said screw advancing mechanism for advancement of a further screw at the end of the retractive movement of said movable parts into a rest position, subsequent to a completed driving home of a screw.
Claim 28
Dependent Claim
179 words
A screw tightening apparatus of the type comprising a motor-driven tool, a screw magazine for screws which are affixed to a strip-like screw carrying medium, and a screw advancing and tightening means for advancing the screws one at a time to a preparatory screw tightening position in which a bit portion of the motor-driven tool may be brought into engagement with the screw for tightening thereof, wherein the screw advancing and tightening means comprises two relatively axially movable but relatively non-rotatable portions, one of which is secured to the motor-driven tool, and the other one of which carries the screw magazine and a spring biased screw advancing mechanism, and wherein the stationary portion is provided with a push and pull member, adapted to cooperate with a rod shaped dog means of said spring biased screw advancing mechanism on tightening of a screw and to trigger said screw advancing mechanism for advancement of a further screw at the end of the retractive movement of said movable parts into a rest position, subsequent to a completed driving home of a screw.
Claim 29
Dependent Claim
47 words
A screw tightening apparatus as claimed in claim 26, wherein said dog means is telescopically movable into said push and pull member and has, at the inner end thereof, a head against which said push and pull member acts on pulling to tension said screw advancing mechanism.
Claim 30
Dependent Claim
76 words
A screw tightening apparatus as claimed in claim 26, wherein said dog means is adapted to actuate said screw advancing mechanism by means of a pivotally journalled bell crank, one lever of which engages into a recess of the dog means, and the other lever of which is pivotally connected to an advancing slide which is reciprocally slidable perpendicularly to the direction of movement of said dog means and has an advancing means for the screws.
Claim 31
Dependent Claim
132 words
A screw tightening apparatus as claimed in claim 28, wherein a spring biased latch is adapted to engage over said one lever of the bell crank during the tightening of a screw and the first portion of the retractive movement of the screw tightening apparatus to thereby momentarily lock said bell crank in a rest position wherein said bell crank is in a rest position wherein said advancing slide occupies a retracted start position, and which latch is adapted to be moved aside into a releasing position by means of an abutment of the dog means at the end of the retractive movement of said movable portions into a rest position to thereby permit said bell crank to pivot in a manner to cause a screw advancing stroke of said advancing slide.
Claim 32
Dependent Claim
65 words
A screwdriver according to claim 1 in which said automatic index means comprises: a. means on said body including resilient finger means for shifting the assemblage in the direction of its length toward the path in which said bit is axially moveable; and b. means connected to said shifting means for so operating said shifting means in response to said retractive movement of said bit.
Claim 33
Dependent Claim
76 words
A screwdriver according to claim 30 in which said guide means comprises: a. four surfaces on said body jointly defining a channel intersecting said axial bit path, said channel being of rectangular cross-section and receptive of the assemblage of screws, said resilient finger means projecting through one of said surfaces for engaging the assemblage, two of said surfaces adjacent to said one surface being spaced apart by a distance greater than the length of the screws.
Claim 34
Dependent Claim
65 words
A screwdriver according to claim 31 in which two of said surfaces lie in planes parallel to the rotational axis of said bit, the marginal portions of said two surfaces which extend in the direction of strip movement and which lie closer to the retracted position of said bit being recessed to receive the screw heads of the screws still in the assemblage of screws.
Claim 35
Dependent Claim
74 words
A screwdriver according to claim 31 in which two of said surfaces lie in planes parallel to the rotational axis of said bit, the marginal portion of one of said two surfaces which extends in the direction of assemblage movement and which lies farther from the retracted position of said bit projecting partially into said channel to reduce its cross-sectional size adjacent to the tip of thd screws still in the strip of screws.
Claim 36
Dependent Claim
49 words
A screwdriver according to claim 30 in which said operating means includes a biasing spring for storing strip-shifting energy, said body having at least one internal stop face engageable by said shifting means for limiting the amount of travel thereon in the direction of the length of the strip.
Claim 37
Dependent Claim
37 words
A screwdriver according to claim 31 which includes a door pivoted on said body and having an inner side which comprises one of said four surfaces, and a door latch acting between said body and said door.
Claim 38
Dependent Claim
20 words
A screwdriver according to claim 35 in which said door latch is detent latch whereby said latch is not attitude-sensitive.
Claim 39
Dependent Claim
61 words
A screwdriver according to claim 36 which comprises a spring urging said door toward an open position, said door latch being movably mounted on the door and having a finger with a tip which is slightly enlarged in the direction that said door is urged by said spring, said tip being received in and projecting through an opening in the body.
Claim 40
Dependent Claim
25 words
A screwdriver according to claim 31 in which said channel in said body terminates near the place where said next of the screws is disposed.
Claim 41
Dependent Claim
25 words
A screwdriver according to claim 8 in which said resilient finger means comprises one said stop finger means disposed between two said driving finger means.
Claim 42
Dependent Claim
54 words
A screwdriver according to claim 8 which includes a door pivoted on said body and forming part of said guide means, a door latch acting between said body and said door, said driving finger means acting on the inner side thereof to assist in opening of the door when the door latch is released.
Claim 43
Dependent Claim
33 words
A screwdriver according to claim 8 in which said body has an internal stop face engageable by said slider for limiting the travel of said driving finger means in the strip advancing direction.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-28 | 1980-09-27 | 1981-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-28 | 1984-09-27 | 1985-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-28 | 1988-09-27 | 1989-03-29 | $7700.00 | Window Closed / Lapsed |