Anyone else old enough to know what this thing was used for?

What this item is

• A vintage reusable bottle stopper designed to reseal glass soda/beer bottles after opening.
• Markings visible on the piece include:
  • “EKCO” and “U.S.A.”
  • “BULL DOG”
  • “PULL DOWN”
  • “PAT. NO. 48661” (as stamped on the top/side)

Name / Common identification

• Often described as: EKCO USA “Bull Dog” Push-Button Bottle Stopper
• Also commonly referred to by function as a pull-down soda stopper (based on the “PULL DOWN” marking).

When it was made (estimated era)

• Based on the listing description you provided, it is commonly dated to roughly 1970–1989.
• The visible patent number stamp suggests the design traces back to an earlier patented concept, even if the specific piece was produced later.

Who made it

• EKCO (U.S.A.) — the maker name is stamped directly on the metal cap.

What it was used for

• Resealing partially finished carbonated drinks (soda, beer, seltzer) to:
  • Help reduce carbonation loss
  • Help prevent spills during short-term storage
  • Keep the bottle covered and more secure between pours

How the mechanism works (simple explanation)

• The red cylindrical section is a rubber plug that fits into the bottle mouth.
• The two curved “wings” act like handles/leverage arms.
• The center post with the round top is the push-button/press point:
  • Pressing/engaging it drives the rubber plug into a tighter seal (a “pull-down” clamp effect), helping the stopper grip the bottle opening more firmly.

Key visual features (from the photos)

• Metal top cap with stamped branding and patent info
• Two symmetrical curved side wings for grip
• Central vertical rod with a round thumb button
• Red rubber stopper body showing age-related wear and darkened spots (typical for vintage rubber)

Why collectors like it

• Functional vintage barware with a distinctive mechanical design
• Clear manufacturer markings (EKCO U.S.A.) that aid identification
• Fits well in collections focused on:
  • Vintage kitchen gadgets
  • Soda/beer memorabilia
  • Primitive or industrial-style antiques