Staple pusher assembly and method of installing same

Patent metadata

Field	Value
Publication number	US-11267117-B2
Application number	US-201916558828-A
Country	US
Kind code	B2
Filing date	Sep 3, 2019
Priority date	Sep 14, 2018
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

A stapler includes a base, a magazine coupled to the base and configured to house staples, and a staple pusher assembly coupled with the magazine and operable to bias staples in the magazine toward a first end of the magazine where staples are driven out of the magazine. The staple pusher assembly includes a staple pusher defining a cavity, and a constant force spring having a first end coupled to the magazine and a second end that is coiled within the cavity in the staple pusher.

First claim

What is claimed is:

1. A stapler comprising:
a base;
a magazine coupled to the base and configured to house staples; and
a staple pusher assembly coupled with the magazine and operable to bias staples in the magazine toward a first end of the magazine where staples are driven out of the magazine, the staple pusher assembly including
a staple pusher defining a cavity; and
a constant force spring having a first end coupled to the magazine and a second end that is coiled within the cavity in the staple pusher for movement with the staple pusher.

2. The stapler of claim 1 , wherein the pusher includes a first portion configured to engage a strip of staples in the magazine and a second portion configured for engagement by a finger of a user of the stapler to move the pusher toward a second end of the magazine opposite the first end of the magazine, and wherein the cavity is formed in an underside of the second portion of the pusher.

3. The stapler of claim 2 , wherein the pusher includes ribs for engagement with the finger of the user.

4. The stapler of claim 1 , wherein the first end of the constant force spring includes an aperture formed therein to secure the first end of the constant force spring to the magazine.

5. The stapler of claim 1 , wherein the staple pusher assembly further includes a coupling member secured to the first end of the constant force spring, the coupling member being coupled to the magazine to secure the first end of the constant force spring relative to the magazine.

6. The stapler of claim 5 , wherein the first end of the constant force spring includes an aperture formed therein to secure the first end of the constant force spring to the coupling member.

7. The stapler of claim 5 , wherein the coupling member includes a projection that engages the magazine.

8. The stapler of claim 7 , wherein the projection is a resilient tab in abutment with a flange of the magazine.

9. The stapler of claim 5 , wherein the coupling member includes at least one projection engaging the first end of the constant force spring to secure the first end to the coupling member.

10. The stapler of claim 1 , wherein there is no shaft or projection within the cavity on which the coiled second end of the constant force spring is supported.

11. The stapler of claim 1 , wherein the staple pusher further includes a projection extending from each one of oppositely facing sides of the pusher and received in respective channels formed in the magazine to guide sliding movement of the staple pusher within the magazine.

12. The stapler of claim 1 , wherein the constant force spring is made from a flat metal strip that is biased toward a coiled configuration, and wherein an uncoiled portion of the constant force spring is adjacent a bottom wall of the magazine beneath staples in the magazine.

13. The stapler of claim 1 , wherein the cavity includes an opening having an opening length L sized to be smaller than a diameter D of the constant force spring in a coiled configuration.

14. The stapler of claim 1 , wherein the cavity is at least partly defined by a circular cavity wall.

15. The stapler of claim 14 , wherein the circular cavity wall has a distal end that engages the constant force spring as the spring uncoils to limit a height of an uncoiled portion of the spring above a bottom wall of the magazine.

16. A stapler comprising:
a base;
a magazine coupled to the base and configured to house staples; and
a staple pusher assembly coupled with the magazine and operable to bias staples in the magazine toward a first end of the magazine where staples are driven out of the magazine, the staple pusher assembly including
a staple pusher defining a cavity; and
a constant force spring having a first end coupled to the magazine and a second end that is coiled within the cavity in the staple pusher;

wherein the first end of the constant force spring includes an aperture formed therein to secure the first end of the constant force spring to the magazine.

17. A stapler comprising:
a base;
a magazine coupled to the base and configured to house staples; and
a staple pusher assembly coupled with the magazine and operable to bias staples in the magazine toward a first end of the magazine where staples are driven out of the magazine, the staple pusher assembly including
a staple pusher defining a cavity; and
a constant force spring having a first end coupled to the magazine and a second end that is coiled within the cavity in the staple pusher;

wherein the staple pusher assembly further includes a coupling member secured to the first end of the constant force spring, the coupling member being coupled to the magazine to secure the first end of the constant force spring relative to the magazine; and
wherein the first end of the constant force spring includes an aperture formed therein to secure the first end of the constant force spring to the coupling member.

Assignees

• Acco Brands Corp

Inventors

• Ventura Carlos Duarte Da Costa
• Lima Pedro Manuel Meneses Brito

Classifications

• B25C5/162 Primary

  with means for holding pusher out of position during re-loading · CPC title

• B25C5/025

  the plunger being manually operated · CPC title