Safety Hammer with Reinforced Head Attachment and Anti-Slip Grip

Patent & Production

At a glance

What the claims cover, in plain language

Claim 1 defines a hammer comprising a stem (1) and a tup/head (5). Key features include:

• A grip section (9) at the right end of the stem with a concave top and anti-slip veins.
• A gear rope (10) attached to the sides of the grip section.
• Alternating external threads and chutes (6) on the left end of the stem.
• A first clamp nut (2), a collar (7), and a second clamp nut (3) arranged on the stem’s left side.
• An inserted link (11) integrally formed at the stem’s left end with a rectangular vertical cross-section.
• The tup (5) has a slot (12) on its right flank that receives the inserted link (11).
• A screw connects the tup and inserted link through the slot.
• Two steel bars (4) are welded to the tup’s left flank, positioned on both sides of the slot, and connect to the lateral surface of the collar (7).
• The collar (7) has internal draw runners (8) equidistantly positioned and slidably connected to the chutes (6).
• Each draw runner (8) has external threads.
• The left-side draw runners connect to the stem via the second clamp nut (3).
• The right-side draw runners connect to the stem via the first clamp nut (2).

Claim 2 specifies that the gear rope (10) has both ends located at the respective both sides of the grip section (9).

This is a simplified reading for orientation only. The legal scope is defined by the exact claim wording in the official Chinese document.

What this means for US production

This patent was filed in China and has lapsed, so it no longer restricts anyone in China. The public record shows no US or other foreign counterpart.

Two points to settle early:

• Other patents may exist. Hand tools are a mature field with extensive existing prior art. While this specific collar-and-link mechanism appears unique in the public record, similar safety features (such as captive head designs or alternative locking wedges) may be covered by active US patents held by major tool manufacturers. A freedom-to-operate (FTO) review is recommended before mass production.
• Material Specifications. The patent mentions steel bars and threads but does not specify grades. Manufacturing must define material standards (e.g., heat-treated steel for the head, corrosion-resistant coatings) to meet durability expectations in the US market.

Customization and manufacturing

What can be customized

Things to plan for (US market)

• ANSI B107.1 - Hand tools standard covering physical properties and performance requirements for hammers.
• OSHA Guidelines - General duty clause requires tools to be maintained in safe working condition; documentation of stress testing helps compliance.
• California Prop 65 - If using certain coatings or materials, warnings may be required regarding chemicals known to cause cancer or reproductive harm.

How a project runs

1. Design Validation - Confirm dimensions of the rectangular link and slot tolerance.
2. Prototyping - Create functional samples using machined stems and cast heads.
3. Testing - Conduct impact tests to verify the collar does not loosen under repeated strikes.
4. Tooling Preparation - Prepare molds for head casting and fixtures for welding/collaring.
5. Production Ramp-up - Begin small batch production with quality checks on thread engagement.

Quantities & timeline

Molds for the hammerhead and machining fixtures for the stem are required. Injection molding is not applicable unless plastic components are added (not in original patent). Welding stations for attaching steel bars to the head need precise jigs. Assembly involves manual or automated tightening of clamp nuts. Send us your target volume, finish preferences, and weight specifications and we will reply with options.

Production notes

Tooling and process

The hammerhead likely requires die-cast aluminum or forged steel depending on desired weight and strength. The stem involves machining to create the rectangular link and threaded sections. Stamping dies may be used for the collar if stamped steel is chosen, though casting is likely more typical for this geometry. Heat treatment is essential for the head’s hardness.

Cost drivers

Material costs for steel and aluminum typically dominate. Machining time for the precise rectangular link and chutes adds expense. The number of stamping dies or casting molds directly impacts upfront tooling costs. Surface finish requirements also influence processing steps.

Prototyping path

We would typically start with a 3D-printed handle mockup to test grip ergonomics. Use a machined or off-the-shelf blade/blank for the head initially. Create heat-treatment trial coupons to validate hardness specs. Assemble a functional sample to test the collar lock mechanism before committing to full tooling.

What we would change before tooling

We would likely add a polymer insert to the grip for comfort, though this deviates from the pure metal design. Verify that the rectangular link shape is optimal for torsional resistance versus a circular pin with flats. Ensure the weld joints between steel bars and head are accessible for automated welding robots.

Common failure points

Edge hardness below spec leads to mushrooming of the head. Pivot pin wear is not applicable here, but thread engagement issues can cause the collar to loosen. Handle creep under load might occur if the stem material is too soft. Coating wear on the chutes could impede draw runner movement. Shaft alignment errors during machining affect the fit of the inserted link.

Patent drawings

Drawings reproduced from the public patent document for reference.

Frequently asked questions

How does the head stay attached?

The head connects to the handle via a rectangular inserted link screwed into place. Additionally, a collar surrounds the handle, connected to the head by welded steel bars. This collar is clamped tight using two nuts, providing a secondary lock that holds the head even if the primary screw fails.

Why is there a rope on the handle?

The gear rope sits at the ends of the grip section. It acts as a physical barrier to stop your hand from sliding off the end of the handle during powerful swings, especially if your hands are wet or gloved.

Is the handle made of wood?

No. The patent describes a metal hammer stem with integrated threads and grooves. The grip section is part of this metal stem, featuring concave curves and textured veins for better hand contact.

Can I customize the head weight?

Yes. While the patent doesn’t specify weights, standard manufacturing practices allow for different head masses (e.g., 16oz to 24oz) by adjusting the casting or forging mold size.

Does the collar loosen over time?

The design uses clamp nuts to secure the collar. Proper torque during assembly is critical. Regular inspection of the nuts is recommended to ensure they remain tight after heavy use.

Are spare parts available?

Since the collar and nuts are threaded components, standard replacement hardware can be sourced if lost. However, the custom-shaped inserted link and welded steel bars make the head-stem assembly difficult to repair piece-by-piece; usually, the whole unit is replaced.

Can this design be made and sold in the US?

The patent was filed in China and has lapsed, and the public record shows no US counterpart, so it does not restrict the design in the US. However, always check for other active patents in the hand-tool sector before launching.

Are you affiliated with the patent owner?

No. IP2M is an independent design and manufacturing service working from the public patent document.

Request a quote

Click Request a Quote below to see our email address - copy it, or open your email app with a ready-made message. Please mention patent CN105818115B in the subject.

Helpful details to include:

• Your company and channel (tool distributor, industrial supplier, brand owner)
• Target head weight and handle length
• Material preference (forged steel, cast iron, etc.)
• Finish (plated, painted, raw)
• Estimated quantity and target price
• Timeline - when you would like samples and the first shipment

You can also reach us at (332) 203-9997.