Strapping tool with energy-release feature

Patent metadata

Field	Value
Publication number	US-12420966-B2
Application number	US-202318837808-A
Country	US
Kind code	B2
Filing date	Feb 8, 2023
Priority date	Feb 18, 2022
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

The present disclosure provides a strapping tool with a scaling assembly including a die assembly and a camshaft. The camshaft includes a cam that engages a cam follower of the die assembly. The cam is shaped so rotation of the camshaft during a scaling cycle causes the cam to force the die assembly to pivot from a home position to a sealing position to form interlocking cuts in overlapping strap portions. Continued rotation of the cam results in the die assembly pivoting back to its home position during an energy-release phase and a return phase of the sealing cycle. During the energy-release phase, the shape of the cam enables the die assembly to pivot a relatively small amount as potential energy is released. During the return phase after this energy is released, the shape of the cam enables the die assembly to pivot a relatively large amount.

First claim

The invention claimed is:

1. A strapping device comprising:
a support comprising a punch;
a sealing assembly comprising:
a die assembly movable relative to the support between a home position and a sealing position, the die assembly comprising a body and a die supported by the body; and
a camshaft rotatable relative to the support, the camshaft comprising one or more cams;

a motor operably connected to the camshaft to rotate the camshaft in a sealing rotational direction to carry out a sealing cycle,
wherein the one or more cams are shaped such that during first and second phases of the sealing cycle, the cam forces the die assembly from the home position to the sealing position, and during third and fourth phases of the sealing cycle, the cam enables the die assembly to move from the sealing position to the home position, wherein the first phase comprises a strap-engage phase during which the die assembly moves from the home position toward the sealing position until the die contacts an upper portion of two overlapping strap portions positioned between the die and the punch, wherein the second phase follows the first phase and comprises a strap-cut phase during which the die assembly reaches the sealing position and causes the die and punch to cooperate to cut the overlapping strap portions, wherein the third phase follows the second phase and comprises an energy-release phase during which the die assembly begins moving from the sealing position back toward the home position, wherein the fourth phase follows the third phase and comprises a return phase during which the die assembly reaches the home position,
wherein an angular displacement of at least one of the one or more cams during the third phase is a third cam angular displacement and a displacement of the die assembly during the third phase is a third die-assembly displacement,
wherein an angular displacement of at least one of the one or more cams during the fourth phase is a fourth cam angular displacement and a displacement of the die assembly during the fourth phase is a fourth die-assembly displacement,
wherein the third cam angular displacement is greater than the fourth cam angular displacement, and
wherein the fourth die-assembly displacement is greater than the third die-assembly displacement.

2. The strapping device of claim 1 , wherein the die assembly further comprises a cam follower supported by the body, wherein the one or more cams comprise a first cam having a variable radius cam surface, wherein the cam surface is shaped such that during the first and second phases of the sealing cycle, the first cam forces the die assembly from the home position to the sealing position, and during the third and fourth phases of the sealing cycle, the first cam enables the die assembly to move from the sealing position to the home position.

3. The strapping device of claim 2 , wherein the die assembly is pivotable relative to the support between the home position and the sealing position, wherein the third and fourth die-assembly displacements comprise third and fourth die-assembly angular displacements.

4. The strapping device of claim 2 , wherein the cam follower is biased into contact with the first cam.

5. The strapping device of claim 4 , wherein the die assembly is forced to move from the sealing position to the home position during the third and fourth phases of the sealing cycle.

6. The strapping device of claim 2 , wherein the third phase takes more time than the fourth phase.

7. The strapping device of claim 2 , wherein an angular displacement of the first cam during the strap-engage phase is a first cam angular displacement and a displacement of the die assembly during the first phase is a first die-assembly displacement, wherein an angular displacement of the first cam during the strap-cut phase is a second cam angular displacement and a displacement of the die assembly during the second phase is a second die-assembly displacement, wherein the second cam angular displacement is greater than the first cam angular displacement.

8. The strapping device of claim 7 , wherein the second phase takes longer than the first phase.

9. The strapping device of claim 7 , wherein the first die-assembly displacement is greater than the second die-assembly displacement.

10. The strapping device of claim 9 , wherein the fourth cam angular displacement is greater than the first cam angular displacement.

11. The strapping device of claim 10 , wherein the fourth die-assembly displacement is greater than the first die-assembly displacement.

12. The strapping device of claim 2 , wherein the camshaft comprises a second cam comprising a lobe, wherein the die assembly comprises a second cam follower, wherein the lobe is positioned such that the lobe engages the second cam follower and forces the die assembly to move to the home position during the fourth phase of the sealing cycle.

13. The strapping device of claim 1 , wherein the support further comprises a base, wherein the punch is fixedly connected to the base and positioned such that, when the die assembly is in the home position, the die assembly is above the base.

14. A strapping device comprising:
a support comprising a punch;
a sealing assembly comprising:
a die assembly movable relative to the support between a home position and a sealing position, the die assembly comprising a body, a cam follower supported by the body, and a die supported by the body; and
a camshaft rotatable relative to the support, the camshaft comprising a cam having a variable radius cam surface;
a die-assembly biasing element biasing the cam follower into contact with the cam surface of the cam; and

a motor operably connected to the camshaft to rotate the camshaft in a sealing rotational direction to carry out a sealing cycle,
wherein the cam surface of the cam is shaped such that during first and second phases of the sealing cycle, the cam forces the die assembly from the home position to the sealing position, and during third and fourth phases of the sealing cycle, the cam enables the die assembly to move from the sealing position to the home position,
wherein the first phase comprises a strap-engage phase during which the die assembly moves from the home position toward the sealing position until the die contacts an upper portion of two overlapping strap portions positioned between the die and the punch, wherein the second phase follows the first phase and comprises a strap-cut phase during which the die assembly reaches the sealing position and causes the die and punch to cooperate to cut the overlapping strap portions, wherein the third phase follows the second phase and comprises an energy-release phase during which the die assembly begins moving from the sealing position back toward the home position, wherein the fourth phase follows the third phase and comprises a return phase during which the die assembly reaches the home position,
wherein the cam rotates more during the third phase than it does during the fourth phase and the die assembly moves more during the fourth phase than it does during the third phase.

15. The strapping device of claim 14 , wherein the support further comprises a base, wherein the punch is fixedly connected to the base and positioned such that, when the die assembly is in the home position, the die assembly is above the base.

Assignees

• Signode Ind Group Llc

Inventors

• Hubschmid Benjamin
• Fischbacher Yannick
• Keller Andreas

Classifications

• B65B13/025 Primary

  Hand-held tools · CPC title

• B65B65/02

  Driving gear · CPC title

• B65B13/327 Primary

  Hand tools · CPC title