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US 2020/0346334 A1Published application
High efficiency torsion spring tacker
AssigneeWorkTools, Inc.
InventorJoel S. Marks
Life of this patent
Estimating the term…
Abstract
A spring energized fastening tool with compact, rigid, low friction working elements is disclosed. A torsion power spring includes forward extending arms with the arms pressing each other proximate a front distal end of the spring. A cantilevered lever links to a handle and engages the spring adjacent to the striker. A bottom loading staple track unlatches and opens through a simple pulling-out action. Structures are provided to enable fitment with a formed sheet metal handle and housing. The fastening tool is particularly simple to assemble, powerful, and of low operating effort.
Claims22
A fastening tool, comprising:
- a housing with a front, rear, top, bottom and sides;
- a handle pivotally attached to the housing at a handle/housing pivot;
- a fastener guide track disposed along the bottom of the housing;
- a striker disposed at the front of the housing including an upper striker position above the track and a lower striker position in front of the track;
- a power spring supported within the housing, the power spring being a torsion type including a spring coil and a central spring coil axis;
- the power spring including a first spring arm extending forward from the coil to a first spring end, the first spring end linked to the striker to move with the striker, a second spring arm extending forward from the coil to a second spring end, the second spring arm pressing the first spring arm at a location of preload to hold the spring in a preloaded condition, the location of preload being forward of the spring coil and closer to the striker than to the spring coil axis;
- a linkage assembly including an upper end and a lower end, the upper end being operatively connected to the handle rearward of the handle/housing pivot, the lower end pivotally connected to the second spring arm proximate the location of preload;
- and
- the fastening tool including a rest condition and a pressed condition, wherein the rest condition includes the first and second spring arms being adjacent to each other near the second spring end and the pressed condition includes the linkage assembly forcing the power spring to deflect, wherein the second spring end is moved away from the first spring arm.
6 more elements
A fastening tool, comprising:
- a housing with a top, bottom and sides, the housing extending longitudinally between a front and a rear;
- a fastener guide track disposed along the bottom of the housing;
- a striker disposed at the front of the housing including an upper striker position above the track and a lower striker position in front of the track;
- a power spring supported within the housing, the power spring being a torsion type including a spring coil;
- the power spring having a first spring arm extending forward from the coil to a first spring end, the first spring end linked to the striker to move with the striker, a second spring arm extending forward from the coil to a second spring end, the second spring arm pressing the first spring arm at a location of preload to hold the spring in a preloaded condition, the location of preload being spaced forward of the spring coil to be adjacent to the striker;
- a lever extending longitudinally from a lever rear end to a lever front end, the lever pivotally attached to the housing near the lever rear end including an upper lever position and a lower lever position;
- a handle pivotally attached to the housing at a handle/housing pivot, the handle/housing pivot being at an upper front location of the housing, wherein a location of the handle rearward of the handle/housing pivot is linked to the lever at a central location of the lever between the lever front and rear ends, and wherein the lever front end is cantilevered forward from the central location and the lever front end includes a pivotal linkage to the second spring arm proximate the location of preload;
- and
- wherein the lever at the lever front end forces the second spring arm to move downward away from the first spring arm in the lever lower position.
6 more elements
A fastening tool, comprising:
- a housing with a bottom, sides, top, and a length of the housing between a housing front and rear;
- a handle pivotally attached to the housing at a handle/housing pivot;
- a fastener guide track disposed along the bottom of the housing;
- a striker disposed at the front of the housing including an upper striker position above the track and a lower striker position in front of the track;
- a power spring supported within the housing, the power spring being a torsion type including resilient wire forming a spring coil and arms;
- the power spring including a first spring arm extending forward from the coil to a first spring end, the first spring end linked to the striker to move with the striker, a second spring arm extending forward from the coil to a second spring end, the second spring arm pressing the first spring arm at a location of preload to hold the power spring in a preloaded condition, the location of preload being forward of the spring coil and closer to the striker than to a center of the spring coil;
- a rigid lever including a lever front end and a lever rear end, the lever front end pivotally linked to the location of preload on the second spring arm;
- the lever extending rearward from the lever front end to a location within the housing vertically aligned with the spring coil;
- a link between the handle and the lever, the link engaging the lever at a central lever location between the lever front and rear ends;
- and
- the lever cantilevered forward from the central lever location to the lever front end.
8 more elements
A fastening tool, comprising:
- a housing having a front, rear, top, bottom, and a length;
- a handle pivotally attached to the housing at a handle/housing pivot;
- a fastener guide track disposed along the bottom of the housing;
- a striker disposed at the front of the housing having an upper striker position above the track and a lower striker position in front of the track;
- a power spring supported within the housing, wherein the power spring includes a first spring arm extending forward from a spring coil to a first spring end that links to the striker at a striker engagement location to move with the striker, a second spring arm extending forward from the spring coil to a second spring end that presses the first spring arm at a location of preload to hold the power spring in a preloaded condition,
- a first forward distance L1 as defined between a center of the spring coil and the striker engagement location, and a second forward distance L3 as defined between the center of the spring coil and the location of preload, such that the ratio of L3/L1≥approximately 60%;
- a lever having a lever front end and a lever rear end, wherein the lever front end is pivotally linked to the location of preload on the second spring arm;
- and
- a link between the handle and the lever, wherein the link engages the lever at a central lever location so that the lever is cantilevered forward from the central lever location to the lever front end.
6 more elements
Dependencies are inferred from the claim text.