Hospital Bed Brake Cam Noise Reduction via Composite Spacer

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Solution Overview

Problem

The existing all-metal cam brake mechanisms in hospital bed rollers generate unpleasant noise when the brake is engaged or released, leading to discomfort and disturbance, especially in environments with multiple beds.

Innovation Solution

Replacing the one-piece metal cam with a multi-part cam consisting of a metal cam body and plastic or elastic spacer elements, which cushions the impact of the pressing element, reducing noise transmission to the brake lever and contact surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an all-metal cam is used in the brake mechanism, then the structural strength and durability are improved, but the noise intensity generated during braking operations increases

Engineering Contradiction:
Improvestructural strengthVSAvoidnoise intensity
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The cam is constructed as a composite structure combining metal and plastic materials. The metal portion provides structural strength and durability, while the plastic portion acts as a noise-damping element that absorbs impact energy and reduces noise generation during braking operations.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

A plastic intermediary element is introduced between the metal cam body and the pressing element. This plastic layer serves as a mediator that cushions the impact force, preventing direct metal-to-metal contact and thereby reducing noise transmission to the brake lever and contact surface.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If a multi-part cam with spacer elements is used, then the noise intensity is reduced, but the device complexity increases

Engineering Contradiction:
Improvenoise intensityVSAvoiddevice complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The cam is divided into multiple functional segments: a metal cam body for structural support and plastic spacer elements for noise damping. This segmentation allows each part to perform its specific function optimally while being integrated into a single composite component that does not significantly increase overall device complexity.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Significantly reduces noise intensity during braking and releasing operations by distributing and damping the impact, providing a more comfortable and quiet environment.

Implementation Method 1

These two spacer elements are preferably made of plastic (or elastic) material. When the brake lever is depressed, the pressure element engages in one of two latching openings. These openings are partially covered by the spacer elements mentioned above, which cushions the impact of the pressing element into the metal part of the cam.

Methodology Applied
Scientific EffectCushioning: Damping

Implementation Method 2

The spacers 3 are preferably made of plastic material so that the impact is distributed between the body 2 of the cam 1 and the contact surface of the lever mechanism of the braking system. In an alternative embodiment, the spacer elements 3 can be made of elastic material

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3053566B1Device for reducing the noise intensity of a brake system from rollers of a hospital bed
Publication Date: 2018.01.24 LINET SPOL
  • EP3053566B1 patent drawingFigure 1
  • EP3053566B1 patent drawingFigure 2

AI summary

Device for reducing the noise intensity of a mechanical braking system for casters of hospital beds, comprising a lever mechanism for releasing a brake of the bed, a rod for force transmission and a cam (1), wherein the cam (1) has a body (2) of the cam (1) and at least one spacer element (3), wherein the body (2) of the cam (1) has a central opening (4) with at least one cutout (5) for fixing at least one spacer element (3), and the circumference of the body (2) of the cam (1) is formed by at least one locking recess (6) and at least one stop (7), and in contact with the body (2) of the cam (1) at least one spacer element (3) with at least one projection (8) for fixing the spacer element (3) is required.