Design Considerations

Home - Changing Industry - Aluminum - Anodizing - Design - Convertable Features - Off Site Transport

G.S.M. Responds to Changing Industry

To fully understand the rationale for the development of the G.S.M. anodized aluminum linen carts, one must look at the changes going on in the laundry industry.

Increased bed demands fuelled by an ageing baby boom generation, have forced launderers to look for more efficent and cost-effective means to handle the mountains of laundry generated.

The general move, over the last two decades, has been to larger, higher volume laundries, serving a number of facilities. Service is centralized, quality is standardized, and state of the art equipment is now seen as the key to real economy.

The infection control concerns of 20 years ago, when washable carts first became an issue, of course, pale in comparison to the problems and precautions today.

As hospitals moved from in-house laundry facilities to regional or central laundries, the traditional steel laundry carts proved too heavy, cumbersom and expensive to transport. The chromed and painted surfaces chipped, peeled and rusted in the cartwash.

The G.S.M. patented linen cart, designed in conjunction with laundry managers, delivered a product that was lighter, more maneuverable, and virtually indestructible.

Attesting to there durable performance, the original order of G-300 convertible carts, put into service in 1972, remain in active daily service at their busy central laundry, supplying five large medical facilities.

Over the years, G.S.M. has remained committed to it's single mandate: to provide linen handling carts of top quality, functional design and durability.
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Why Aluminum?

One need only look to aluminum's extensive use in other industries to appreciate it's unique suitability for hospital and laundry use. Its extremely high strength to weight ratio is fully exploited in the aircraft industry. The use of aluminum in the food and bevrage industry underline its usefulness in a "clean" environment. Aluminum siding and windows are widely used for their durable, attractive and rust-free performance.

Through the use of aluminum, coupled with carefully engineered structural sections and welding procedures, we have achieved a cart with a load carrying capability of 1000#, at a total weight of 100#. With the average steel cart weighing in at as much as 300#, the savings are quickly evident in terms of wear and tear on the casters, the enviroment in which the carts are used, and on the personnel using the cart.

In terms of the launderer who requires trucking for distribution, the weight reduction of up to 9000# per trailer load (45 carts per load), will have the welcome impact of reducing both feul and maintenance costs.
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Anodizing - The Natural Choice

After completion of the welding and major assemblies, the entire cart is anodized. Anodizing is an electro-chemical process whereby the naturally occuring oxide film on aluminum is thickened by passing an electrical current through sulphuric acid electrolyte, using the fabricated aluminum as the anode. To achieve maximum durability and corrosion resistance, the resultant oxide film is sealed by immersion is a hot water sealing solution. The purpose of anodizing is to impart to the metal surface specific properties of the oxide - hardness, wear and corrosion resistance and an asthetically pleasing appearance. G.S.M. chose anodized aluminum to meet the specific requirements of health care related linen handling based on three main conciderations:

Anodizing is an increase in a naturally formed part of the base material, and cannot separate from the base in flakes or chips. Conversely, chrome plate is an "add-on" which may spontaneously, or as a result of physical damage, become separated from the base material. When this happens the unprotected steel will begin to rust. Flakes of hard chrome plate separated from the cart can cause serious health and safty concerns.
The fact that the final process in anodizing is immersion in hot water means that the regular washing of G.S.M. anodized aluminum carts with hot water or even steam, serves to inforce rather than damage the exterior finish.
Through normal use, a linen transport cart will be subjected to abuse that may penetrate even the hardest surface protection. When this happens to chromed or painted steel, rusting begins at the surface and moves into the base material and under undamaged plating. If anodized aluminum becomes damaged to the point of anodic film penetration, the natural oxide film forms immediately. Regardless of the extent of the physical injury (and even if welding repairs are required), protection against corrosion remains.

Superior By Design

Having determined that anodized aluminum is the right material to use, the method of construction must be tailored to the special properties of this material. At G.S.M. carefull design, combined with attention to user comments, has resulted in a product with the following important features:

The horizontal members are a specifically engineered aluminum extrusion. This is punched and formed in a continuous length around the vertical corner menbers. The extrusion's channel shape allows for structural weld in both vertical and horizontal planes to be hidden from view.
The shelf sheets (both fixed and convertable models) are captive in the structural extrusion of the cart body. Although rivets are used to eliminate rattle, they are not depended upon for support.
The base to which the casters are bolted is formedinto the channel shaped extrusion of the cart. This gives two advantages:
- Under normal loading situations, the stress is transferred directly from the casters to cart structure, and is not transferred through base mounting rivets;
- if a torsional load is applied to the caster mountings, as when a loaded cart hits a bump, the stress on the base rivets is perpendicular to the rivets, and thus is a shear force and never a pull out fourse.
Vertical closure tubes (3/4" dia. 1/16 wall) pass through punched holes in the horizontal structural members, and are welded to these members. This means that, as the welding contributes strength to the total structure, the unique joint design greatly increased the integrety of the weld. (series G-700, 800 excepted)
To ensure the safty of those who handle out linen carts, we have designed all of the extruded components with large radius corners.

Convertable Feature

Our Convertible Shelf Cart, G-300 model, features a unique spring loaded hinge design which offers the following advantages:

The shelf hinge pins are supported on spring loaded inclined slots. To reconfigure from shelf to bin position, the shelf is swung forward on the hinge, using the cutaway handhold. Then vertical, a sligh upward shift against the hinge assembly will position the hanging shelf behind the stainless steel stops beneigth it. No additional bolts or catched are required to maintain "bin position".
In shelf position, the shelves are supported by welded, 3/16" x 2" corner gussets, which prevent accidental self dislocation during transport.
The hinge assembly is inside the corner post, removing a potentially dangeous protusion from outside the cart, and protecting the hinge from damage.

How Can One Cart Do the Job of Two

In our opinionm a true exchange system is the most effective and efficient method for delievey in hospitals and nursing homes. It allows good inventory control and turnover, more accurate quotas, and involves the least ammount of linen handling from laundry to user. Our G-300 convertible carts are an integral part of this system.

Using out G-300 convertible carts in an exchange system, one cart does the job of two:

At the laundry , a one or two day, predetermined ward quota is loaded onto the cart (shelf position). Carts are often weighed at this point, then covered with nylon or plastic covers. The cart is transported to the facility, and taken directly to the ward.

Once at the ward, any linen excesses from the percious day's cart can be top loaded to the new cart. The new cart replaces the previous day's cart, and remains on the ward. The previous da's cart, is converted to bin position, and loaded with soiled, bagged linen for transport back to the laundry.

After unloading of the soiled bags at the laundry, the carts are passed through a cartwash. Reconfigured to shelf position, they are ready to begin the cycle again.
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Off Site Transport.

Without a doubt, the most critical time for cart structural integrity is during over the road, trailer transport to off-site locations. During transport, tortional forces and impact loads can be extreme, to the point of literally shaking apart the fasteners and clips of traditional "component assembled" carts.

These extreme forces have been one of G.S.M.'s primary design considerations and are addressed with the following design features.

G.S.M. carts are an all welded construction, delivered fully assembled. Mechanical fastners such as rivets and bolts are used only to secure hardware and to eliminate rattle, and in no case are they depended upon for structural purposes.
The use of an integrated assembly of vertical structural members passing through horiontal structural members.
Welding at each contact point of vertical and horizontal members.
A reinforcing brace under all shelves, and double reinforcing of base shelves in all convertable carts.
Reinforcing wear plates positioned at the level of truck retention bar contact.
Specificly deveoped UHMW plastic bumpers that are highly resistant to cuts and pullout slide smoothly against each other.

For more information on G.S.M. Carts Email us.
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