How to avoid structural looseness when folding and storing a three in one cart?

The three in one baby stroller, with its core advantages of switchable stroller, cradle, dining chair and other usage modes, balances practicality and convenience, and has become a commonly used equipment for modern infant and toddler family travel and home care. The folding and storage function, as the core convenience design of the three in one cart, is not only convenient for home storage, but also meets the needs of carrying outside. However, the operational standardization during the folding and storage process directly affects the stability and service life of the cart structure. Unlike single function strollers, three in one strollers have a more complex structure and more detachable components. Improper operation and neglect of inspection and maintenance during folding and storage can easily lead to problems such as loose folding mechanisms, component detachment, and locking failure. This not only shortens the product's service life, but also may cause safety hazards such as body shaking and accidental folding in subsequent use, posing a threat to the safety of infants and young children during transportation. Currently, according to the "Child Care Products Safety Child Cart" (GB/T 14748-2025) and related industry standards, clear requirements have been formed for the design and use of the folding mechanism of the three in one stroller, clarifying the core points of avoiding structural looseness during folding and storage. This can not only help consumers operate in a standardized manner and avoid risks, but also promote industry enterprises to strengthen product structure design and quality control, guiding the industry to develop towards standardization and safety.
From the current situation of the industry, the market demand for three in one carts continues to grow, but some consumers lack the correct understanding of folding and storage operations. At the same time, some companies simplify the design of folding mechanisms and use inferior connectors to compress costs, resulting in frequent structural loosening problems. According to industry inspection data and quality investigation, 35.8% of the unqualified products of the three in one cart have loose folding mechanisms and failed locks. Among them, structural looseness caused by improper folding and storage operations accounts for over 60%, mainly manifested as incomplete unlocking during folding, forced folding, failure to lock and fix after storage, and long-term neglect of maintenance leading to component wear and looseness. In addition, some low-priced "three no" products have unreasonable folding mechanism designs and do not have dual locking protection. After only about 2000 folding cycles, abnormal noise and looseness occur, far below the industry's standard requirement of 5000 no failures, further exacerbating safety hazards. Therefore, clarifying the methods to avoid structural looseness when folding and storing three in one carts, popularizing scientific operation and maintenance knowledge, has important industry value and practical significance for ensuring the safety of infants and young children, regulating market order, and promoting high-quality development of the industry.
1、 Preparation before folding: Conduct a comprehensive inspection to eliminate any potential looseness hazards
A comprehensive inspection of the three in one cart before folding and storage is the foundation to avoid structural damage and looseness during the folding process. The core is to confirm that the various components of the cart are firmly connected and the folding mechanism is normal. At the same time, it is necessary to do a good job in the early stage to lay the foundation for standardized folding. Specific attention should be paid to three core points.
1. Check the status of the components and confirm that they are securely connected
Before folding, it is necessary to check the connection status of each key component of the cart one by one, with a focus on identifying areas that are prone to looseness, to avoid structural deformation caused by loose components during folding. The inspection points include: the connection parts between the frame and the convertible components such as the cabin, cradle, dining chair, etc., confirming that the buckles and bolts are firmly fixed without looseness or shaking. If the bolts are found to be loose, they should be tightened in a timely manner and anti loosening gaskets should be added to prevent them from falling off under force during folding; As the core load-bearing component, the folding hinge needs to be checked for tight connection, no jamming, abnormal noise, or looseness, to ensure smooth rotation of the hinge. At the same time, check whether the dust-proof and wear-resistant gaskets at the hinge are intact. If they are missing or damaged, they should be replaced in a timely manner to avoid further wear and tear causing structural looseness. In addition, it is necessary to check the connection between the wheels and the frame to ensure that the wheel axle is firmly fixed without shaking, and to avoid uneven force on the body caused by wheel displacement during folding, which may lead to structural looseness. Before the first use, it is recommended to focus on checking the tightening of all screws to avoid potential loosening hazards from the source.
2. Unlock the folding mechanism to prevent forced operation
The folding mechanism of a three in one stroller is usually equipped with dual locking protection. It is necessary to strictly follow the operating steps in the product manual to complete all unlocking actions before folding, to prevent forced folding and violent operations, and to avoid damaging the folding mechanism and causing structural looseness. The key points of operation include: first unlock the fixing devices of detachable components such as the cabin and cradle, separate them from the frame and store them separately to avoid uneven force caused by component interference during folding; To unlock the folding locking device of the frame again, most products need to complete two consecutive actions of "pressing the unlock button+pulling/pressing the push rod". Upon hearing a "click" sound, the unlocking is completed. After confirming that the unlocking is in place, fold slowly. Do not forcefully press or fold without fully unlocking to avoid deformation of the folding mechanism, failure of the locking device, and subsequent structural looseness.
3. Clean up debris and reposition components to avoid interference
Before folding, it is necessary to clean the debris inside the cart cabin to avoid getting stuck in the folding mechanism, which may cause the folding to be unsmooth and lead to component wear and looseness; At the same time, return the adjustable components such as the sunshade, handrails, and pedals of the trolley to their original positions, ensuring that they are tightly attached to the frame without protruding or interfering parts, and avoiding uneven stress and damage to the folding mechanism caused by component misalignment during folding. In addition, the brake system of the trolley needs to be locked to prevent the body from sliding during folding, which may cause operational errors and indirectly lead to structural looseness.
2、 Folding process: Standardized operation to reduce structural wear and tear
The standardization of the folding process directly determines whether the trolley structure will loosen. The core principle is "smooth operation, uniform force distribution, and gradual progress". Combining the structural characteristics of the three in one trolley, the focus is on three operational points to avoid structural damage and loosening caused by improper operation.
1. Smooth operation, avoid violent folding
When folding, it is necessary to keep the cart steadily placed on a flat ground, hold the push rod or designated folding part with both hands, slowly apply force, and gradually complete the folding, avoiding excessive force and rapid pressing, to prevent the folding mechanism from being impacted, causing the hinge to loosen and the frame to deform. During the folding process, it is necessary to observe the movement trajectory of each component. If any jamming or obstruction is found, the operation should be stopped immediately to investigate whether there are any issues such as component interference or improper unlocking. After solving these problems, continue folding without forcefully applying force to avoid damaging the locking device and connecting parts of the folding mechanism. The folding mechanism of the high-quality three in one cart has been folded 5000 times without any malfunctions, while violent operation can significantly shorten its service life and cause early loosening.
2. Uniform force distribution to avoid local overload
The structure of the three in one cart is complex, and when folding, it is necessary to ensure that the body is evenly stressed to avoid excessive pressure on a single part, which may cause the structure to loosen. The key points of operation include: when folding the frame, both hands should apply symmetrical force to avoid one-sided force causing the frame to tilt and uneven force, which can lead to loose hinges and connectors; When folding detachable components such as cabins and cradles, it is necessary to lift the center of gravity of the components to avoid pulling or hanging them with one hand, and to prevent damage or loosening of the connecting parts of the components. At the same time, it is necessary to avoid collisions between the vehicle body and hard objects such as the ground and walls during the folding process, in order to prevent damage to the frame and folding mechanism, which may indirectly cause structural looseness.
3. Pay attention to details and avoid component misalignment
During the folding process, special attention should be paid to the fit and misalignment of the components to ensure that they fold according to the design trajectory, fit tightly, and have no misalignment or jamming. For example, when folding the frame, it is necessary to ensure that the front and rear frames are in place, and the folding locking device can be smoothly inserted into the slot without looseness or rebound; When storing detachable components, they should be folded in the designated way to avoid deformation caused by random placement, which may affect the stability of the subsequent connection with the frame. In addition, during the folding process, it is necessary to avoid fingers from entering the folding gap, which not only prevents pinch injuries, but also avoids component misalignment caused by finger obstruction, leading to structural looseness.
3、 Storage and Preservation: Scientific Protection to Prevent Long term Loosening
The storage method after folding and storing directly affects the stability of the trolley structure. Improper long-term storage can easily lead to rusting of the folding mechanism, aging and loosening of components. Therefore, it is necessary to do a good job in fixing and protecting after storage, focusing on three core points.
1. After folding, lock and fix the body structure
After the trolley is fully folded, the folding locking device should be activated in a timely manner to firmly lock the folded body, avoiding accidental unlocking or loosening of the folding mechanism during storage and transportation, which may cause the body to unfold or components to shift. After locking, gently shake the vehicle body to confirm that it is securely locked without any looseness or shaking. Some products are equipped with hooks or straps to further secure the folded vehicle body, reducing shaking during transportation and avoiding wear and looseness of the folding mechanism. At the same time, the maximum load-bearing capacity of a folded cart is usually 5kg, and it is not recommended for item transportation. Long term load-bearing will exacerbate structural damage and cause looseness.
2. Reasonable storage to avoid environmental damage
When storing, it is necessary to choose a dry, ventilated, and flat environment to avoid placing the cart in damp, dark, and corrosive gas areas, and to prevent the folding mechanism and connecting parts from rusting and corroding, which may cause structural looseness; At the same time, avoid pressing heavy objects on the folded cart to prevent deformation of the frame and folding mechanism, which may cause component loosening. When storing, a dust cover can be used to wrap the cart to prevent dust from entering the gaps of the folding mechanism, wearing down parts, and affecting the stability of folding and locking. In addition, it can be stored normally in areas below 5000 meters above sea level, but it is important to note that changes in air pressure may affect the elasticity of plastic components. When storing, it is necessary to avoid sudden temperature changes.
3. Regular inspections and timely maintenance
Even if not used for a long time, it is necessary to regularly inspect and maintain the folded cart to avoid component aging and loosening. It is recommended to check the locking status and hinge connection of the folding mechanism once a month. If any looseness, jamming, or abnormal noise is found, tighten the connecting parts and add special lubricant in a timely manner; Clean the folding interface with alcohol cotton pads every quarter to remove dust and impurities, and perform anti-corrosion treatment on metal parts to avoid rusting; According to the frequency of use, a comprehensive inspection of the folding mechanism should be conducted every 6 months to replace severely worn components such as hinges and washers, ensuring structural stability. In addition, after each use, it is necessary to check whether the folding mechanism is intact and promptly clean the debris in the gaps to prepare for the next folding and storage.
4、 Industry control and consumption guidelines
In order to standardize the design, production, and use of the three in one cart folding mechanism, the industry has established a multidimensional control system: firstly, standard control. GB/T 14748-2025 standard further refines the design requirements and strength indicators of the folding mechanism, clarifies that the folding locking device needs to have a dual protection function, and the folding mechanism needs to pass more than 5000 folding cycles without failure testing. At the same time, it needs to meet the requirements of dynamic durability testing, and eliminate products with unreasonable design and substandard performance; The second is production control. Regular enterprises strictly screen suppliers of core components such as connectors and hinges for folding mechanisms, conduct on-site inspections of raw materials, strengthen quality inspections during the production process, promote automated production equipment to improve process accuracy, and ensure that folding mechanisms are firmly connected and locked reliably; The third is market supervision. Market supervision departments regularly conduct random inspections of three in one carts, focusing on checking the firmness, locking reliability and other indicators of folding mechanisms. They recall and rectify unqualified products, and severely crack down on "three no products" and violations of 3C certification; The fourth is industry self-discipline. Mainstream enterprises actively enhance product safety standards, improve folding operation guidelines in product manuals, and promote the upgrading of folding mechanisms towards greater firmness, durability, and convenience.
For consumers, when using a three in one cart, it is necessary to strictly follow the folding and storage standards, and follow the following guidelines: firstly, prioritize selecting products with 3C certification and compliance with GB/T 14748-2025 standards, check product testing reports, confirm that the strength, durability and other indicators of the folding mechanism meet the standards, and avoid purchasing low-priced "three no" products; The second is to carefully read the product manual, proficiently master the correct operation steps of folding, unlocking, and locking, and eliminate violent operations and forced folding; Thirdly, before and after folding and storage, it is necessary to check the structure of the trolley, promptly identify any looseness or abnormal noise, and promptly repair or replace any parts found; The fourth is to scientifically store the trolley, perform regular maintenance, and extend the service life of the folding mechanism; If the folding mechanism experiences serious looseness or locking failure, immediately stop using it and contact the manufacturer for repair or replacement to avoid safety hazards.
The structural stability of the three in one cart during folding and storage is the core link to ensure the service life and safety of the product. Its protective points run through three stages: preparation before folding, folding process, and storage. It is necessary to balance operational standardization and scientific maintenance, and comply with national and industry standards. Industry enterprises need to adhere to the safety bottom line, strengthen the design and production control of folding mechanisms, and enhance the stability of product structure; Consumers need to establish a scientific awareness of operation and maintenance, master the core points of avoiding structural looseness, standardize operation and regular maintenance, in order to effectively leverage the multifunctional advantages of the three in one stroller, provide safe and convenient guarantees for infants and young children's travel and home care, and promote the healthy, orderly, and high-quality development of the infant and young children's travel supplies industry.