Trimline phone history

Trimline phone history

Phones with dialing in the handset are extremely popular today, with thousands of different cordless, corded, and cellular models. The design makes a lot of sense, and started with telephone repairmen's "buttsets" in the 1930s.

The first popular residential phone with dialing in the handset is the Trimline, which was first offered by the Bell System in 1964, and is still made today.

It was a curvy, comfortable, contoured set with a twist the dial, located in the handset, now "came to you." It was perfect for making calls while in bed, or while sitting in the kitchen, or locations with limited space.

Today, the Trimline is considered an American classic, but in 1964 it was dramatically different than any other telephone. Developed with the help of the noted industrial design firm Henry Dreyfuss Associates, it was selected by The Museum of Modern Art in New York City for its permanent design collection. just one year after its introduction.

In 1977, Fortune magazine named the Trimline one of the country's 25 best-designed products. It was also selected for the "Designed in America" exhibit produced by the U.S. Information Agency.

The introduction of the Trimline took an exhaustive amount of research more than a decade's worth of work on the part of AT&T. Scientists at the company's Bell Laboratories had to not only perfect the inner workings of the new phone, they also had to make it easy to handle, light to hold and good looking.

That was no easy task. In fact, the evolution of the Trimline is a little like the tale of the ugly duckling.

The Trimline telephone is based on a homely looking handset with a built-in dial that was developed in 1939 to help AT&T craftsmen test telephone lines. The development of a dial-in-handset for the public began with an experimental model constructed at Bell Labs in 1952.

Subsequent models included one known as the Demitasse that had a small dial around the mouthpiece. A version known affectionately as the Schmoo had a bulge in the middle of the handset in order to accommodate a full-sized dial.

Each early version of the new telephone was thoroughly tested for customer acceptance. The Demitasse, for example, was put through its paces with customers in Brooklyn, N.Y.; San Leandro, Calif.; and Columbus, Ohio. The public liked the concept but not the style.

The Schmoo, on the other hand, had a more attractive silhouette but was just too hard to handle, in the opinion of customers in a New Brunswick, N.J., test group. The rotary dial made the telephone bulge out too much in the middle. People just couldn't hold on to it comfortably.

AT&T tried various ways to make the dial smaller, including a dial with spokes in the rim instead of holes. That idea was rejected quickly; fingers kept slipping off the spokes. Making the holes smaller made it difficult for many people to dial.

The breakthrough came when a Bell Labs engineer developed a moveable fingerstop that slid subtly past the zero whenever a number was dialed, thus eliminating the space between the "1" and the "0." No one previously had questioned the space between the "1" and the fingerstop. Many great inventions are the result of people questioning why things are the way they are.

The new "floating" fingerstop worked well, but AT&T wondered whether it would meet customer approval. As it turned out, most users took the change in stride, and a good many weren't even aware that the fingerstop moved at all.

Taking advantage of the smaller dial and other innovations such as printed circuits and miniaturization, the transmitter and receiver became smaller, as did the ringer, which now fit snugly into the telephone's trim base.

In the summer of 1964, AT&T began manufacturing the Trimline in Indianapolis, and the first new phones were offered to customers in Michigan in 1965.

The success of the Trimline is based in large part on the human factors research that went into perfecting a phone that would please the public at large.

Trimline Design

  • The first Trimline models used incandescent dial lights powered by a power transformer plugged into a standard 120VAC outlet. The bulky transformer and the need for an outlet was criticized by many consumers, and Western Electric subsequently redesigned the Trimline to use a green LED backlit dial powered by current from the phone line. AT&T later repainted and resold early-model pre-divestiture Trimlines without a transformer as 'non-lighted' models.

  • The Trimline had a sleek, curved plastic housing that took up little space compared to earlier phones. Unfortunately, the glass-smooth and shallowly-curved plastic proved difficult to retain between cheek and shoulder for hands-free communication without slipping, and this problem was never corrected over the life of the phone.

  • The Trimline was the first new AT&T/Western Electric phone made in both rotary dial and Touch-Tone versions from the start of production.

  • The Trimline was the first American phone to achieve some design recognition in Europe, where it was referred to as the 'Manhattan' model.

  • Today, similarly designed models are sold by many companies. AT&T retained the Trimline name for the later 'Trimline III', a more compact successor featuring squared corners and straight lines.

  • Early Touch -Tone Trimlines had round buttons and clear plastic backplates surrounding the buttons. Later versions had square-ish buttons.

  • The first Touch-tone phones had ten buttons. Twelve-button phones, with pound and star, came later.

  • The original handset cords were round, with five conductors and large plugs held in place with stainless-steel clips. This cord design was also used in 851-series "cuckoo clock" multi-line wall phone. Later phones used standard modular cords.

  • Handsets, bases and cords were packed separately in telephone trucks, so an installer could assemble Touch-Tone or rotary, desk or wall models, with less inventory than would be required if complete phones were carried.

  • Specialized phone models using the Trimline handset include elevator phones, multi-line phones, blackboard and bulletin board  phones, chest phones and hospital bedside phones with hands-free operation.

Trimline Timeline

1965
Original Trimline is introduced in both rotary and Touch-Tone versions. First Touch-Tone phones lack pound and star buttons.
Early 70s
The clear plastic button backplate with colored paper backing matching the color of the phone is replaced with an aluminum backplate on the round button Touch-Tone phones. Also at this time, the round handset cords using proprietary connectors are replaced with modern flat modular cords and jacks. On all Trimline phones, the screw cover above the dial changes from reading "Bell System made by Western Electric" to just "Trimline" with a bell logo to the left of the text.
Late 70s
A green LED light powered by the phone line replaces the incandescent lamp. The Touch-Tone version now sports slightly larger, square keys, as opposed to the earlier small round keys, and now has an aluminum faceplate behind the keys.
1983
AT&T begins selling phones, including the Trimline, to the public (as opposed to their previous rental-only policy) through its newly created American Bell subsidiary.
1984
AT&T is divested of its regional operating companies and is prohibited from using the Bell name or logo, so the American Bell brand is dropped and replaced with simply AT&T. All telephone production continues as normal. The Touch-tone Trimline phone is heavily modified with the following new features: electronic chirp ringer in the handset, replacing the previous mechanical bell ringer. keys are now made of a soft rubber material, line switch (switch hook) eliminated from base, moved to top of phone just below the receiver, handset screw cover no longer says "Trimline"; made smaller in the middle to conform to new switch hook location; only one cord is required for the telephone connection -- a part-coiled, part-straight design that passes through a groove on the bottom of the phone base, which now has no purpose other than as a place to keep the handset .
1985
The rotary Trimline is discontinued, and further modifications are made to the touch-tone model: desk or wall convertible, eliminating separate desk and wall models; Touch-Tone/dial pulse switch, eliminating separate Touch-Tone and rotary models; redial and mute functions; single cord to connect telephone is eliminated, base-to-handset and base-to-jack cords reinstated
1986
With the closing of the Western Electric Indianapolis Works, Trimline production is moved overseas to Singapore and China. Modifications included: receiver volume control; ringer loudness switch moved to base of the phone; bottom of the base is now made of plastic, with a lead weight inside the base; only one screw is used to hold the handset together; location of screw and screw cover is moved to below the Touch-Tone pad; 2220 Trimline is dropped as a model number, replaced by the 210, 220, and 230.
1993
Trimline is updated with the following features: soft rubber keys are again replaced with hard plastic keys, similar to the late 70s and early 80s models, but the keys are even larger and rectangular rather than square; the faceplate behind the keys, aluminum since the late 70s LED conversion is now a dark gray plastic with a matte surface; production is moved to Mexico; Caller ID models, the 250 & 260, are introduced under the Trimline brand. The design shares nothing in common with the 210 model.
1996
Lucent Technologies is spun off from AT&T, and minor modifications are made to the Trimline : Phones are marked "Lucent Technologies", though this turned out to be temporary, and the boxes and marketing materials were always co-branded with AT&T; "Trimline" again marked above the Touch-Tone pad on the matte surface; ringer loudness switch is moved back to the handset, but the ringer remains inside the base
1997 Lucent enters a short-lived joint venture with Philips, creating Philips Consumer Communications. More Trimline changes: handset screws are eliminated completely. Handset is only held together by "snap" ends at both ends of the phone, above the receiver and below the microphone; phones are again branded AT&T (Lucent name is dropped); ringer moved into handset.
2000 Lucent sells its consumer division to Hong Kong company VTech, which establishes Advanced American Telephones to market AT&T-branded phones. VTech moves production from Mexico to China.
 

Similar Phones from Other Makers

The Trimline is design is ubiquitous, with probably thousands of variations from hundreds of manufacturers, some licensed by AT&T, some not.

  • "Trendline" was the ITT/Cortelco version. It was initially identical to the Trimline, but has gone through many modifications. It was originally made in Mississippi, and now comes from China.

  • "Slenderet" was the Stromberg-Carlson/Comdial version.

  • "Styleline" was the GTE version. Although it had the same basic shape as the Trimline, it was bigger, clunkier, and uglier, as was usual with GTE adaptations of AT&T designs. It used a really weird cord connector. Strangely, GTE phone stores also offered the ITT Trendline.

  • "Contempra" and Contemprette" were dial-in-handset phones from Northern Telecom/Nortel, but were wedge-shaped, not rounded like the Trimline.


  • Based on info from AT&T, Bell System Memorial, Wikipedia, personal knowledge.