Futon Frame Styles
There are two major differences between the bi-fold and tri-fold futon frame types. The first difference is the number of times the futon mattress must fold when converting from the sitting to sleeping position. The tri-fold requires the futon mattress to be folded twice, while the bi-fold requires that the mattress fold only once. The second major difference between the two futon frame designs is that the tri-fold utilizes the shorter width of the mattress for seating while the bi-fold utilizes the longer length. This gives the inherent advantage to the bi-fold because it looks much more like a conventional sofa bed than does the tri-fold. It also provides a larger seating area.
Two basic types of tri-fold exist. The first type includes frames with legs like The Basic Brouwer Bed. Look-alikes, usually using the name "A-Frame,” are often imported. These frames are nicely finished and are moderately priced.
The other type of tri-fold is the most basic of futon frames. These frames have no legs and sit directly on the floor. Most of these frames are made from pine or poplar and many go to the retailer unfinished. They may be painted or stained to suit the buyer’s preference.
Ron Massey of Horndove started experimenting with a sling chair which he ultimately developed into the T.H.I.S frame.
The bi-fold is now the industry standard and the more popular of the two basic styles. These sofa bed look-alikes also come in two basic categories, those with arms and legs and those that sit directly on the floor.
Since the introduction of bi-folds in 1984-85, the futon industry has grown into a viable home furnishings category. The bi-fold futon frames (the well manufactured and designed ones, that is) look and work much more like the conventional sofa beds they compete with on retail sales floors.
Futon Frame Mechanisms
Futon Life Tip:
Make sure your manufacturer/distributor guarantees their frames against breakage under normal use. Also, educate your customers on how a specific frame works and emphasize that proper use of the mechanism will insure a long life for their new futon sofa-bed. How-to videos and sales training programs are also recommended helps some suppliers may offer.
Most futon frame designs utilize some variation of the slider mechanism: two or four nylon rollers/sliders fit in between the slat racks and the arm assemblies, in grooves that allow the futon frame to convert from sitting to sleeping and back again. Some manufacturers, though, have taken a different route. They have attempted to fit a metal mechanism to a wooden frame. The best designs are now using metal-reinforced wooden bases. The metal reinforcement makes up for the lighter weight of the wood and can even add an element of style.
Many futon frames also employ the so-called "kicker” mechanism. The kicker utilizes a small piece of wood that swings freely from the back of the seat rack. When the seat rack is raised to vertical, the kicker falls into a position where it wedges itself between the seat rack and the back rest. When the seat rack is pushed down, the "kicker” forces the back rest to return to the seating position in one fluid motion. All this happens from the front of the frame, making the conversion easy and usually trouble free.
Futon frame technology has taken some interesting twists and turns over the years. If you’re interested in a more detailed look at the early and progressive futon frame designers and their inventions, take a look at this in-depth article cataloguing the developments in frame styles and mechanisms over the years.
Materials: Wood and Metal
Futon Life Tip:
All "Pine" is not created equal
There are several manufacturers who make product almost exclusively for the futon industry. These companies construct their frames from Southern Yellow Pine. This particular pine is very strong, very hard (as pine goes), and it is also quite heavy. Because of its characteristics it lends itself very well to the rigors that befall most convertible futon furniture. Many other types of pine or more precisely wood from the conifer or softwood species do not lend themselves to the convertible futon frame. Most of these woods, though wonderful for building houses, are too light and brittle for the stresses of converting a futon frame with a sixty pound futon on it. Ask your manufacturer what kind of "pine" they are using, and also ask them for a sample of the wood. You should also read the Wood section of the Futon Primer.
The futon furniture manufacturer has to deal with two issues the traditional sofa bed maker doesn’t face. One issue is the design aesthetic of an all-wood frame. The fact that most futon frames are made entirely of clear (no knots or bark), finished wood adds some considerable cost and design constraints to the frame. Traditional sofas and sofa beds can use heavier, unfinished wood that is not clear. Hidden under layers of padding and fabric is usually a glued and screwed frame that is very sturdy, but if it were left uncovered, it would not draw much of a crowd. The futon frame must pass the muster of an exposed wooden exoskeleton, where the fit and finish is open to public scrutiny. The weight of this clear, dimensioned lumber must be heavy enough to handle the stresses of conversion and yet be light enough to not look out of proportion.
Common woods used in futon furniture manufacturing include oak, ash, pine, maple, and cherry. The type of wood strongly influences the price of the frame, with pine and poplar being less expensive and most hardwoods being more expensive.
Quite a few companies construct their frames from Southern Yellow Pine. This particular pine is very strong, very hard (as pine goes), and heavy. Because of its characteristics, it lends itself very well to the rigors that befall most convertible futon furniture. Many other types of pine, or, more precisely, wood from the conifer or softwood species, do not lend themselves to the convertible futon frame. Most of these woods, though wonderful for building houses, are too light and brittle for the stresses of converting a futon frame with a 60-pound futon on it.
For more information about wood, see the detailed primer article about wood and its various properties and the application of those properties in furniture manufacturing.
You can also reference the book Wood Handbook: Wood as an Engineering Material, published by The US Department of Agriculture's Forest Products Laboratory. This comprehensive, 500-page publication covers a multitude of topics concerning wood and wood products, including chapters on availability, physical properties, mechanical properties, fastenings, structural analysis, bonding wood, finishing wood, wood preservation and many others.
Futon Life Factoid:
The $39, (retail at $59 to $129) all-metal, black tube futon frame has caused many problems for the futon industry and consumers. This cheap, low-quality product has given many people a negative perception of futon furniture that years of quality manufacturing have not been able to overcome. However, not all metal futon frames are poorly made. The next generation of metal frames and mechanisms are of a much higher quality and provide a much better value. Rather than being a temporary piece of furniture that will break and be discarded quickly, a good quality metal futon can be a stylish and functional addition to your living space.