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Since 67 seatbelts came up again on this forum, I thought post a draft of a proposed Restorer Article. Comments would be welcome, it's a little long but here it is:
Anatomy of an RCF-65 Seat Belt Buckle (C2: 66L-67 Seatbelts)
By Jerry Fuccillo NCRS #42179
The lap seatbelts on my 1967 Corvette Convertible were in terrible shape with rust stains on the buckle ends, and the inability to easily adjust the seat belts. With every new passenger, especially my wife, it became a long protracted affair to get the belt properly adjusted. With my wife, the solution was usually “Oh, forget about it, Let’s take my car.”
So, I decided to put the seat belts on my list of Corvette projects. Rather then send them out for some expensive restoration job, and having the desire to tinker with things, I took on the restoration myself. I asked a lot of questions on the NCRS Technical Discussion Board, researched the archives and the Restorer CD, and did some other research on the history of seat belts, and this particular model of seat belt buckle.
The RCF-65 Seat Belt Buckle was used on late1966 and 1967 Corvettes, as well as 1966-67 GM passenger cars (Chevelles, Impalas, GTOs, Buicks, Cadillacs, etc.) as deluxe seat belts. They may have been used on passenger cars in 1968 and after, although seat belts in Corvettes I believe were changed in 1968. The RCF-65 was invented by Robert C. Fisher, thus RCF, and was patented in 1965. Robert C. Fisher was a GM employee, and holds numerous patents on seatbelts and parts of seatbelt assemblies up though 1977. There is an RCF-67 seatbelt buckle which was a smaller version of the RCF-65, used through the 1970's and which was probably the most numerous seatbelt buckle used.
DISASSEMBLY
In beginning my restoration project, the first thing I had to figure out was how to get the buckle apart without breaking anything. I posted a question on the NCRS Board and had my answer by the end of the day. You insert a small flat blade screwdriver between the buckle top and back on the end opposite the tongue receiving end, and then pry up and out on both sides. The buckle top then pops off with the button insert.
Photo 1 is a photograph showing the prying position with the top partially off:
To disassemble the other parts from the buckle back, it’s easiest to unstitch the end of the belt. The belt retainer has a strap around it whereby a triple fold of the belt will not fit through. It is possible to remove the pawl plate and pawl spring without removing the belt from the retainer with a little work, but my belt retainer was the most rusted part and you have to remove the belt to get to that part. Once the belt is removed, the belt retainer, pawl plate and pawl spring just slide out of the buckle back.
THE PARTS
Photo 2 is a photograph of a disassembled RCF-65 Seat Belt Buckle showing the six refinished parts to it:
The six parts (in my terminology) are:
1. Upper left- the Buckle Back. This part is chrome steel and has the Hamill RCF-65 on the underside with use instructions.
2. Lower left - Belt Retainer. This is a cast steel bar with rounded top and flat bottom. It has a bent steel strap around it which is peened in place at the ends of the cast steel bar. The Belt Retainer slides into the Buckle Back (after parts 3 & 4 are in place), The seat belt goes up through the slot in the buckle back, then between the strap and bar of the retainer, around the bar, and then back through the slot in the buckle back.
3. Upper middle - Pawl Plate. This is a pressed steel plate which wedges into and pivots along the tongue side of the buckle back. The raised edge along the rectangular hole in the Pawl Plate engages the tongue of the other side of the belt.
4. Lower middle- Pawl Spring. This is a complicated spring steel bent assembly which goes under the pawl plate and holds the Pawl Plate in an upward position to engage the tongue. Compressing the Pawl Plate and spring downward releases the tongue.
The Pawl Spring also has a couple of spring ears on the lower vertical part which bear against the strap on the belt retainer and hold the belt to a locked position around the belt retainer and to the buckle back.
5. Upper right- Button Insert. The button insert is a decorative painted metal piece which has a riveted-on logo. I believe that most Corvettes have the Chevrolet Bowtie along there are some reports of the Fisher Body logo in the Judging Manual. I believe that the Bowtie is probably unique to the Corvette, as all the other passenger car buckles I’ve seen with the same model buckle have either Fisher Body or GM logo on them. The Button Insert pivots along the edge of the Buckle Top and sits on top of the Pawl Plate.
6. Lower right- Buckle Top. The Buckle Top, although it looks like solid stainless steel, is of plated steel with stainless steel brushed satin finish. Try a magnet on them. The Buckle Top pivots around two tabs in the Buckle Back at the tongue end and then snaps over the opposite end with a pressure fit.
REASSEMBLY
The parts go back together in reverse order of disassembly. The Pawl Plate is assembled to the top of the Pawl Spring first. This assembly is then slid into the Buckle Back. The Belt Retainer is then slid into the back, with the strap against the Pawl Spring, and the rounded surface to the top. The seat belt is then brought up through the slot in the Buckle Back, between the strap and bar of the retainer, around the retainer bar, and then back through the slot in the Buckle Back. The button insert is then inserted into the pivot groove in the Buckle Top at the tongue end. Then hold the buckle vertical with the tongue end down, and align the groove on the top with the tabs on the back and get ready to snap the top (with the insert in place) over the upper end of Buckle Back. Before you snap it shut, test the button to make sure it moves against the pawl plate and spring free and clear. If so, snap it shut by squeezing the buckle together.
I sewed the belt end back together in a triple fold using an antique (50's vintage) Singer sewing machine. I used a size 110/18 needle, heavy upholstery thread, and did two straight stitches at ½" apart, 10 stitches per inch through the 3 layers of belt.
FINISHES
1. Buckle Back Luckily, the outside of the buckle back was in fairly good shape although I had some rust and corrosion on the inside from the Pawl Spring. I wire brushed the corrosion off with a Dremel wire brush, and then applied a Simichrome Polish to the inside and outside.
2. Belt Retainer. On the first belt, this part was so rusted I couldn’t tell what the original finish was so I assumed bare metal. On the passenger side buckle, I found remnants of a gold dichromate or anodizing. I soaked these parts in Naval Jelly and Jasco Metal Etch. Then I wire brushed them with a wheel on a drill, and then with a Dremel wire brush, to bare shiny metal. I then sprayed them with Eastwood gold dichromate base.
The proper finish here would be zinc or cad plating with a dip in yellow dichromate.
3. & 4. Pawl Plate and Pawl Spring. The Pawl Plate and Pawl Spring had a flat black finish, probably black phosphate on the plate and enamel on the spring. I soaked these in lacquer thinner, followed by metal etch, cleaned them up, and spray painted them with flat black Rustoleum.
5. Button Insert. I spent the most time with the Button inserts mainly trying to find the right color blue for the Bowtie. Working from a pictures of original buckles and restored ones, as well as my original buckles, I experimented with no less then six shades of nail polish (OPI Aruba Blue was close), Ford and Chrysler touchup paint, with no cigars. I went to the local hardware store for the spray paint color charts. I found that Denim Blue was about the right color although too light, and Royal Blue was too dark, so I bought a can of each and decided to mix.
After stripping all of the paint from the inserts by soaking in lacquer thinner, I then mixed the two spray paint colors by spraying into jar, first the lighter color and then the dark, and thinning with lacquer thinner. At about 50-50 I finally got what I thought was the right shade.
Then with a very fine brush, I flooded the Bowtie with the mix on a horizontal surface. Once that dried, I then rubbed off the paint on the edges of the Bowtie and on the Chevrolet lettering, first with a flat piece of wood and then with a exacto knife.
Next step was to mask the Bowtie with blue painters take, and cutting around the Bowtie with an exacto knife. Once masked, I spray painted the insert with semi-flat black dash paint. Photo 3 is a picture of the finished insert posted on the NCRS forum:
Got to admit, that the insert was a little banged up to begin with, but they are hard to find. The bowtie is cast metal, riveted or staked to the insert plate. Another NCRS member has told me that he removed it from the insert plate, sprayed all the parts, and JB welded it back on.
6. Buckle Tops. My buckle tops were badly pitted with the lower plating showing through, and one was even bent and cracked. If they are pitted or heavily scratched, there is not much you can do with them, except send them out for replating or look for replacements from Corvettes or passenger cars at junkyards. Since one of mine was bent and cracked I opted for the latter. As I was scheduling a junkyard expedition, another NCRS member seeing my post of the insert, offered me a pair of 1976 service replacement belts with buckles in good shape, and I took it.
SERVICE REPLACEMENT SEAT BELT BUCKLES
I found that the RCF-65 seat belt buckles on the 1976 service replacement seat belt buckles were slightly different then my original 1967 buckles although all parts were readily interchangeable. They were different as follows:
a. The belt retainer was now one rectangular cast piece in the shape of a capital “I” with no side strap. The elimination of the strap allows taking the buckle off the belt without unstitching the end of the belt. The belt seemed to adjust more freely with this new retainer.
b. The pawl spring seemed to be a little stronger and higher, and the pawl plate had a slightly broader ridge where the tongue engages the pawl plate. The little ears on the pawl spring which would bear against the strap on the old belt retainer, were also eliminated, as they would now bear against the belt itself with the new retainer. I believe that the design changes to the pawl spring and pawl plate were probably a correction of a problem with the RCF-65, known as “inertial unlatching”. Inertial unlatching is the tendency of the seat belt to unlatch due to a sudden shock, and can be demonstrated by latching the belt, holding the belts tight, and then slapping the back of the buckle against a hard surface. The momentum of the pawl plate compresses the spring, and the belt buckle unlatches. I tried this with my original belts a number of times against a piece of wood and they unlatched every time. With the service replacement buckles on the same test they stayed latched every time.
So, if you have a soft belly, there’s probably no worry about inertial unlatching. But if you have a six pack down there, or want the ultimate in safety as far as lap belts go, then you should go to the newer pawl spring and pawl plate. I put the service replacement spring, plate, top and insert button (after refinishing), on my original belts.
Photo 4 is the finished product. I left my original tattered labels on as they were original, and only one was stamped 7E67 which is the 7th week of 1967. This is quite a lag to my June 29th 1967 assembly date, so I guess they were scraping the bottom of the barrel for mine. If I ever change the belting I’ll get reproduction labels, but these belts washed in Simple Green looked pretty good to me:
The Numbers
On each of the buckle parts except the pawl spring, there are these three or four digit numbers which I could not make any sense of as to whether they were a date code or some kind of serial number. My original buckles had an equivalent number on each part between the two. Others I have seen have different numbers on the backs between pairs. I surmise that the numbers are production run numbers, and somewhere in parts heaven (or on Joe Lucia’s bookshelf), there is a book of production numbers with corresponding dates.
This story is getting a little long, so I guess I’ll break it here. Next one will be on the retractor ends.
Jerry Fuccillo
#42179
Anatomy of an RCF-65 Seat Belt Buckle (C2: 66L-67 Seatbelts)
By Jerry Fuccillo NCRS #42179
The lap seatbelts on my 1967 Corvette Convertible were in terrible shape with rust stains on the buckle ends, and the inability to easily adjust the seat belts. With every new passenger, especially my wife, it became a long protracted affair to get the belt properly adjusted. With my wife, the solution was usually “Oh, forget about it, Let’s take my car.”
So, I decided to put the seat belts on my list of Corvette projects. Rather then send them out for some expensive restoration job, and having the desire to tinker with things, I took on the restoration myself. I asked a lot of questions on the NCRS Technical Discussion Board, researched the archives and the Restorer CD, and did some other research on the history of seat belts, and this particular model of seat belt buckle.
The RCF-65 Seat Belt Buckle was used on late1966 and 1967 Corvettes, as well as 1966-67 GM passenger cars (Chevelles, Impalas, GTOs, Buicks, Cadillacs, etc.) as deluxe seat belts. They may have been used on passenger cars in 1968 and after, although seat belts in Corvettes I believe were changed in 1968. The RCF-65 was invented by Robert C. Fisher, thus RCF, and was patented in 1965. Robert C. Fisher was a GM employee, and holds numerous patents on seatbelts and parts of seatbelt assemblies up though 1977. There is an RCF-67 seatbelt buckle which was a smaller version of the RCF-65, used through the 1970's and which was probably the most numerous seatbelt buckle used.
DISASSEMBLY
In beginning my restoration project, the first thing I had to figure out was how to get the buckle apart without breaking anything. I posted a question on the NCRS Board and had my answer by the end of the day. You insert a small flat blade screwdriver between the buckle top and back on the end opposite the tongue receiving end, and then pry up and out on both sides. The buckle top then pops off with the button insert.
Photo 1 is a photograph showing the prying position with the top partially off:
To disassemble the other parts from the buckle back, it’s easiest to unstitch the end of the belt. The belt retainer has a strap around it whereby a triple fold of the belt will not fit through. It is possible to remove the pawl plate and pawl spring without removing the belt from the retainer with a little work, but my belt retainer was the most rusted part and you have to remove the belt to get to that part. Once the belt is removed, the belt retainer, pawl plate and pawl spring just slide out of the buckle back.
THE PARTS
Photo 2 is a photograph of a disassembled RCF-65 Seat Belt Buckle showing the six refinished parts to it:
The six parts (in my terminology) are:
1. Upper left- the Buckle Back. This part is chrome steel and has the Hamill RCF-65 on the underside with use instructions.
2. Lower left - Belt Retainer. This is a cast steel bar with rounded top and flat bottom. It has a bent steel strap around it which is peened in place at the ends of the cast steel bar. The Belt Retainer slides into the Buckle Back (after parts 3 & 4 are in place), The seat belt goes up through the slot in the buckle back, then between the strap and bar of the retainer, around the bar, and then back through the slot in the buckle back.
3. Upper middle - Pawl Plate. This is a pressed steel plate which wedges into and pivots along the tongue side of the buckle back. The raised edge along the rectangular hole in the Pawl Plate engages the tongue of the other side of the belt.
4. Lower middle- Pawl Spring. This is a complicated spring steel bent assembly which goes under the pawl plate and holds the Pawl Plate in an upward position to engage the tongue. Compressing the Pawl Plate and spring downward releases the tongue.
The Pawl Spring also has a couple of spring ears on the lower vertical part which bear against the strap on the belt retainer and hold the belt to a locked position around the belt retainer and to the buckle back.
5. Upper right- Button Insert. The button insert is a decorative painted metal piece which has a riveted-on logo. I believe that most Corvettes have the Chevrolet Bowtie along there are some reports of the Fisher Body logo in the Judging Manual. I believe that the Bowtie is probably unique to the Corvette, as all the other passenger car buckles I’ve seen with the same model buckle have either Fisher Body or GM logo on them. The Button Insert pivots along the edge of the Buckle Top and sits on top of the Pawl Plate.
6. Lower right- Buckle Top. The Buckle Top, although it looks like solid stainless steel, is of plated steel with stainless steel brushed satin finish. Try a magnet on them. The Buckle Top pivots around two tabs in the Buckle Back at the tongue end and then snaps over the opposite end with a pressure fit.
REASSEMBLY
The parts go back together in reverse order of disassembly. The Pawl Plate is assembled to the top of the Pawl Spring first. This assembly is then slid into the Buckle Back. The Belt Retainer is then slid into the back, with the strap against the Pawl Spring, and the rounded surface to the top. The seat belt is then brought up through the slot in the Buckle Back, between the strap and bar of the retainer, around the retainer bar, and then back through the slot in the Buckle Back. The button insert is then inserted into the pivot groove in the Buckle Top at the tongue end. Then hold the buckle vertical with the tongue end down, and align the groove on the top with the tabs on the back and get ready to snap the top (with the insert in place) over the upper end of Buckle Back. Before you snap it shut, test the button to make sure it moves against the pawl plate and spring free and clear. If so, snap it shut by squeezing the buckle together.
I sewed the belt end back together in a triple fold using an antique (50's vintage) Singer sewing machine. I used a size 110/18 needle, heavy upholstery thread, and did two straight stitches at ½" apart, 10 stitches per inch through the 3 layers of belt.
FINISHES
1. Buckle Back Luckily, the outside of the buckle back was in fairly good shape although I had some rust and corrosion on the inside from the Pawl Spring. I wire brushed the corrosion off with a Dremel wire brush, and then applied a Simichrome Polish to the inside and outside.
2. Belt Retainer. On the first belt, this part was so rusted I couldn’t tell what the original finish was so I assumed bare metal. On the passenger side buckle, I found remnants of a gold dichromate or anodizing. I soaked these parts in Naval Jelly and Jasco Metal Etch. Then I wire brushed them with a wheel on a drill, and then with a Dremel wire brush, to bare shiny metal. I then sprayed them with Eastwood gold dichromate base.
The proper finish here would be zinc or cad plating with a dip in yellow dichromate.
3. & 4. Pawl Plate and Pawl Spring. The Pawl Plate and Pawl Spring had a flat black finish, probably black phosphate on the plate and enamel on the spring. I soaked these in lacquer thinner, followed by metal etch, cleaned them up, and spray painted them with flat black Rustoleum.
5. Button Insert. I spent the most time with the Button inserts mainly trying to find the right color blue for the Bowtie. Working from a pictures of original buckles and restored ones, as well as my original buckles, I experimented with no less then six shades of nail polish (OPI Aruba Blue was close), Ford and Chrysler touchup paint, with no cigars. I went to the local hardware store for the spray paint color charts. I found that Denim Blue was about the right color although too light, and Royal Blue was too dark, so I bought a can of each and decided to mix.
After stripping all of the paint from the inserts by soaking in lacquer thinner, I then mixed the two spray paint colors by spraying into jar, first the lighter color and then the dark, and thinning with lacquer thinner. At about 50-50 I finally got what I thought was the right shade.
Then with a very fine brush, I flooded the Bowtie with the mix on a horizontal surface. Once that dried, I then rubbed off the paint on the edges of the Bowtie and on the Chevrolet lettering, first with a flat piece of wood and then with a exacto knife.
Next step was to mask the Bowtie with blue painters take, and cutting around the Bowtie with an exacto knife. Once masked, I spray painted the insert with semi-flat black dash paint. Photo 3 is a picture of the finished insert posted on the NCRS forum:
Got to admit, that the insert was a little banged up to begin with, but they are hard to find. The bowtie is cast metal, riveted or staked to the insert plate. Another NCRS member has told me that he removed it from the insert plate, sprayed all the parts, and JB welded it back on.
6. Buckle Tops. My buckle tops were badly pitted with the lower plating showing through, and one was even bent and cracked. If they are pitted or heavily scratched, there is not much you can do with them, except send them out for replating or look for replacements from Corvettes or passenger cars at junkyards. Since one of mine was bent and cracked I opted for the latter. As I was scheduling a junkyard expedition, another NCRS member seeing my post of the insert, offered me a pair of 1976 service replacement belts with buckles in good shape, and I took it.
SERVICE REPLACEMENT SEAT BELT BUCKLES
I found that the RCF-65 seat belt buckles on the 1976 service replacement seat belt buckles were slightly different then my original 1967 buckles although all parts were readily interchangeable. They were different as follows:
a. The belt retainer was now one rectangular cast piece in the shape of a capital “I” with no side strap. The elimination of the strap allows taking the buckle off the belt without unstitching the end of the belt. The belt seemed to adjust more freely with this new retainer.
b. The pawl spring seemed to be a little stronger and higher, and the pawl plate had a slightly broader ridge where the tongue engages the pawl plate. The little ears on the pawl spring which would bear against the strap on the old belt retainer, were also eliminated, as they would now bear against the belt itself with the new retainer. I believe that the design changes to the pawl spring and pawl plate were probably a correction of a problem with the RCF-65, known as “inertial unlatching”. Inertial unlatching is the tendency of the seat belt to unlatch due to a sudden shock, and can be demonstrated by latching the belt, holding the belts tight, and then slapping the back of the buckle against a hard surface. The momentum of the pawl plate compresses the spring, and the belt buckle unlatches. I tried this with my original belts a number of times against a piece of wood and they unlatched every time. With the service replacement buckles on the same test they stayed latched every time.
So, if you have a soft belly, there’s probably no worry about inertial unlatching. But if you have a six pack down there, or want the ultimate in safety as far as lap belts go, then you should go to the newer pawl spring and pawl plate. I put the service replacement spring, plate, top and insert button (after refinishing), on my original belts.
Photo 4 is the finished product. I left my original tattered labels on as they were original, and only one was stamped 7E67 which is the 7th week of 1967. This is quite a lag to my June 29th 1967 assembly date, so I guess they were scraping the bottom of the barrel for mine. If I ever change the belting I’ll get reproduction labels, but these belts washed in Simple Green looked pretty good to me:
The Numbers
On each of the buckle parts except the pawl spring, there are these three or four digit numbers which I could not make any sense of as to whether they were a date code or some kind of serial number. My original buckles had an equivalent number on each part between the two. Others I have seen have different numbers on the backs between pairs. I surmise that the numbers are production run numbers, and somewhere in parts heaven (or on Joe Lucia’s bookshelf), there is a book of production numbers with corresponding dates.
This story is getting a little long, so I guess I’ll break it here. Next one will be on the retractor ends.
Jerry Fuccillo
#42179
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