Caster Anti-Tilt Device
Patent No. US11673427 (titled "Caster Anti-Tilt Device") was filed by Cart Source Llc on Aug 17, 2020.
What is this patent about?
’427 is related to the field of casters, specifically anti-tilt devices used with casters on shopping carts. These devices address the problem of users circumventing anti-theft systems that lock a shopping cart's wheels when it crosses a boundary. A common workaround is to tilt the cart, lifting the locked wheel. Thus, there is a need for a simple and robust anti-tilt mechanism.
The underlying idea behind ’427 is to add a fixed bar that extends across the wheel's tread at a specific angle. This bar is positioned such that when the cart is tilted, the bar contacts the ground before the cart can be tilted far enough to roll on the remaining wheels. The bar's angle and height are carefully chosen to allow normal cart operation on level ground while effectively preventing tilting beyond a certain threshold.
The claims of ’427 focus on an anti-tilt device for a caster, comprising face plates with flanges that attach to the caster frame, legs extending from the face plates, and a bar connecting the legs. The key feature is the bar's defined angle relative to the wheel's tread face, achieved through a bend in the legs. The flanges prevent the anti-tilt device from rotating relative to the caster frame.
In practice, the anti-tilt device is mounted to the caster frame using the same bolt that secures the wheel. The flanges on the face plates grip the sides of the caster frame, preventing rotation. When the cart is tilted, the angled bar contacts the ground, preventing further tilting and thus stopping the cart. The bend in the legs is crucial for positioning the bar at the correct angle and height relative to the wheel.
The design aims for simplicity and robustness. The anti-tilt device can be manufactured from a single piece of stamped metal, reducing complexity and potential failure points. The flanges provide a secure, non-rotating attachment to the caster frame, and the angled bar effectively limits tilting without interfering with normal wheel operation. This contrasts with prior solutions that may be more complex, prone to dislodging, or less effective at preventing tilt.
How does this patent fit in bigger picture?
Technical landscape at the time
In the early 2020s when ’427 was filed, anti-theft systems for shopping carts were commonly implemented using locking casters that engaged upon crossing a defined boundary, at a time when tilting the cart to circumvent the locking mechanism was a known workaround, and when hardware or software constraints made robust, multi-part anti-tilt devices non-trivial.
Novelty and Inventive Step
The claims were rejected under 35 U.S.C. 112 and 103. The Examiner objected to the specification and drawings. The Examiner also provided suggested claim amendments. The prosecution record does NOT describe the technical reasoning or specific claim changes that led to allowance.
Claims
The patent has 13 claims, with claim 1 being independent. Independent claim 1 is directed to an anti-tilt device for a caster. The dependent claims elaborate on the features and configurations of the anti-tilt device described in the independent claim.
Key Claim Terms New
Definitions of key terms used in the patent claims.
Patent Family
File Wrapper
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Date
Description
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US11673427
- Application Number
- US16995596
- Filing Date
- Aug 17, 2020
- Status
- Granted
- Expiry Date
- Apr 27, 2041
- External Links
- Slate, USPTO, Google Patents